Clinical Dentistry

CHURCHILL’S POCKETBOOKS Clinical Dentistry This page intentionally left blank CHURCHILL’S POCKETBOOKS Clinical Dentistry 4th EDITION Edited by Professor Crispian Scully CBE MD, PhD, MDS, MRCS, BSc, FDSRCS, FDSRCPS, FFDRCSI, FDSRCSE, FRCPath, FMedSci, FHEA, FUCL, FSB, DSc, DChD, DMed (HC), Dr.hc Co-Director, WHO Collaborating Centre for Oral Health-General Health; Emeritus Professor, UCL (London) and Visiting Professor, Universities of Athens, Edinburgh, Helsinki, Hertfordshire, Middlesex and Plymouth Edinburgh London New York Oxford Philadelphia St Louis Sydney Toronto 2016 © 2016 Elsevier Ltd. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein). First edition 1998 Second edition 2002 Third edition 2007 Fourth edition 2016 ISBN 978-0-7020-5150-0 International ISBN 978-0-7020-5149-4 Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Content Strategist: Alison Taylor Content Development Specialist: Lynn Watt Project Manager: Julie Taylor Designer: Miles Hitchen Illustration Manager: Emily Costantino Printed in China Last digit is the print number: 9 8 7 6 The publisher’s policy is to use paper manufactured from sustainable forests 5 4 3 2 1 Preface to the Fourth Edition As initiators of Clinical Dentistry, and editors of the first three editions, we are not only pleased to note the impressive success of the book internationally but, in our increasingly busy senior academic roles, are also delighted to pass the reins to our long-time colleague and friend, Professor Crispian Scully CBE, and wish him and the contributors continued success with the 4th edition. Professor Ivor Chestnutt Cardiff Professor John Gibson Glasgow The primary objective of this Pocketbook was to provide a readily accessible source of information when it is most needed, as an aidemémoire prior to carrying out clinical tasks or to enable students (at undergraduate and postgraduate level) to apprise themselves of important details prior to tutorials and seminars. Those aims remain. In a publication of this nature, information must be presented in a concise and, at times, didactic fashion. The intent is to include sufficient basic information to permit examinations to be passed. However, the desire of an educationalist is always to promote deep learning and the layout and content of the text are intended to motivate and guide the reader to the appropriate parts of more substantive texts, many of which have proven both inspirational and motivational for the editors and contributors of this book throughout their careers. This textbook is widely used by more and more undergraduate dental students, vocational dental practitioners, general professional trainees, dental surgeons in primary care and in the hospital service, as well as dental care professionals in-training and post-qualification. I was requested to take on the editing of the 4th edition. For this edition I have expanded the size and type of authorship. Although a large proportion of current contributors were involved in earlier editions, some previous authors were unavailable to help, so we have also recruited a range of other top people in their fields. The current authors are all experienced clinicians, teachers and/or managers within their individual specialties and emphasis has been given to information of practical clinical significance. Descriptions of rarely encountered conditions and situations have been deliberately minimized. vi • Preface to the Fourth Edition In updating this edition, each author has addressed significant changes within his or her areas of expertise and I am grateful to them for their enthusiasm and great industry and particularly for complying with deadlines. Thus this new 4th edition has not only been invigorated and enhanced but also the chapter order has been rearranged. We have also expanded on practical aspects related to the regulator – the General Dental Council; and on the dental team roles, and practice management. The book has been written to be used in conjunction with Scully’s Handbook of Medical Problems in Dentistry (Elsevier 2016) and now includes issues related to overseas dental staff, access for disabled, advertising, aetiopathogenesis of dental disease, assaults on staff, behaviour at work and outside (GDC standards), building design, chaperoning, clothing, finance management, foundation and vocational training, governance, health and safety, hiring and firing, identifying staff, independent practice, infection control, information technology, management skills, marketing, NHS regulations, overseas staff, professionalism, protected characteristics, significant event analysis, time-keeping and things staff must do before starting work and leaving a job. The aims and objectives remain the same – to educate and inspire each member of the whole dental team, whether in-training or post-qualification. I am indebted for support from the authors, Professor Ivor Chestnutt, Professor John Gibson, Professor Justin Stebbing and at Elsevier, Mrs Lynn Watt and Mrs Alison Taylor. Our thanks are also due to former contributors, including Iain. B. Buchanan, Barbara. L. Chadwick, Ivor. G. Chestnutt, John Gibson, Jason Leitch, Joe McManners, Jeremy Rees and Dave Stenhouse. Crispian Scully London, 2016 Contributors Stephen Barter BDS MSurgDent RCS Specialist Oral Surgeon Perlan Specialist Dental Centre Hartfield Road Eastbourne, UK Stephen Barter is Clinical Director of Perlan Specialist Dental Centre, Eastbourne; Specialist in Oral Surgery and Hon. Lecturer in the Department of Periodontology, UCL Eastman Dental Institute, London; ITI Fellow and past Chairman of the UK and Ireland ITI Section and has been involved in the teaching and development of dental implantology for over 20 years. John A.D. Cameron BDS DGDP LLB (Hons) Senior Clinical/Dental Adviser Practitioner Services NHS National Services Scotland Edinburgh; University of Aberdeen Dental School Aberdeen, UK John Cameron is Senior Dental Adviser at NHS National Services Scotland, Senior Clinical Lecturer at the University of Aberdeen Dental School, Lead for Law, Ethics and Professionalism. He is also Chairman of the Dentists Health Support Programme and Trust. viii • Contributors Iain Chapple BDS FDSRCPS PhD FDSRCS CCST (Rest Dent) Periodontal Research Group and MRC Centre for Immune Regulation School of Dentistry College of Medical and Dental Sciences University of Birmingham Birmingham, UK Professor Iain Chapple is Head of Periodontology at the University Birmingham’s School of Dentistry and Clinical Lead for an NHS service base of 6 million. He is Associate Editor of Journal of Clinical Periodontology and Periodontology 2000 and former Scientific Editor of the British Dental Journal and former Associate Editor of Journal of Periodontal Research. President of The British Society of Periodontology (2014–2015), President of The Periodontal Research Group of the International Association of Dental Research (2007), Treasurer and Executive Committee member of the European Federation of Periodontology (EFP) (2007–2013), EFP Scientific Advisory Committee Chairman (2013–2015), Secretary General (2016–), EFP Workshop Co-Chairman (2009–current). He has written and edited seven books and 16 book chapters and published over 140 full papers on Medline. He was awarded the Tomes Medal by the Royal College of Surgeons of England in 2012. Fiona Cox B.Ed MInstLM Ferndale Dental Clinic Ltd Devizes, UK Fiona Cox is co-owner at Ferndale Dental Implant and Cosmetic Clinic. She has a wide experience in management within the private health sector and the NHS dental and medical health fields. Contributors • ix Martyn Cox BSc (Hons) BDS MFGDP RCS (Eng) FRSM, PhD Clinical Director Ferndale Dental Implant Clinic Implant mentor and tutor Dentale Advanced Implant course, Honorary Specialist Oral Surgeon, Solihull Hospital Lecturer Martyn Cox is the Clinical Director at Ferndale Dental Implant and Cosmetic Clinic, Devizes. He is a clinical trainer/lecturer and mentor in Advanced Implantology in Bristol and Shrewsbury, an Honorary Oral Surgeon at Solihull Hospital, Birmingham and a lecturer on the FGDP Oral Surgery course. Martyn has been awarded numerous research prizes in the UK and has published widely in both UK and international peer-reviewed journals including several oral cancer textbooks and has lectured on implantology, oral cancer and human papilloma virus genetics in the UK, Europe and the USA. Daljit Gill BDS BSc MSc FDS RCS MOrth FDS (Orth) RCS (Eng) UCLH Eastman Dental Hospital London, UK Dr Daljit Gill is a Consultant Orthodontist at Great Ormond Street NHS Foundation Trust and UCLH Eastman Dental Hospital. He has written a number of textbooks and is involved in training orthodontists, therapists and nurses. x • Contributors Nikos Donos DDS MS FHEA FDSRCSEngl PhD Head Centre for Oral Clinical Research Professor and Chair Periodontology and Implant Dentistry Honorary Professor, UCL Eastman Dental Institute, UK Honorary Professor, University of Hong Kong Honorary Professor, Griffith University, Australia Centre for Clinical Oral Research Institute of DentistryBarts and The London School of Medicine and DentistryQueen Mary University of London (QMUL) Awarded the title of Honorary Professor at the Faculty of Dentistry in Hong Kong (2009) and the title of Adjunct Professor at the Dental School, Griffith University, Australia (2012), Professor Donos is involved as editorial board member in a number of international and national peer-reviewed journals in the field of Periodontology and Implant Dentistry and has published extensively. In 2011, he was awarded the prestigious annual IADR-Periodontology Group Award in Periodontal Regenerative Medicine. His clinical expertise is in the field of Periodontics and Implant Dentistry and he has significant experience in periodontal/bone regeneration and implant related surgical procedures as well as treatment of peri-implantitis, topics which he regularly lectures on at a national and international level. David H. Felix BDS MB ChB FDS RCS (Eng) FDS RCPS (Glasg) FDS RCS(Ed) FRCP(Ed) Dean of Postgraduate Dental Education NHS Education for Scotland Edinburgh, UK Dr David H. Felix is Postgraduate Dental Dean, NHS Education for Scotland and Chair of the Joint Committee for Postgraduate Training in Dentistry. Previously Consultant in Oral Medicine Glasgow Dental Hospital and School. He is a former Dean of the Faculty of Dental Surgery of The Royal College of Surgeons of Edinburgh and a former President of the British Society for Oral Medicine. Mark Griffiths MBBS FDS RCS BDS Visiting Professor, UCL (Eastman Dental Institute); Honorary Research Fellow, School of Physiology, Pharmacology and Neuroscience University of Bristol Bristol, UK Mark Griffiths is Visiting Professor, UCL (Eastman Dental Institute), London, UK and Honorary Research Fellow, School of Physiology, Pharmacology and Neuroscience at the University of Bristol. He is a retired NHS Consultant in Special Care Dentistry at the Bristol Dental Hospital. Holder of Patent: Monitoring electrical activity (Electroencephalograph) and Member of University of Bristol Neuroscience Community. Contributors • xi Athanasios Kalantzis DipDS MFDSRCS MBChB MRCS FRCS (OMF) Oral and Maxillofacial Surgery Consultant Central Manchester Foundation Trust Manchester, UK After qualifying in Dentistry in Athens, Greece and in Medicine in Sheffield, UK, Mr Kalantzis trained in Oral and Maxillofacial Surgery at the Oxford University Hospitals and served as Members Representative and Fellows in Training Representative of the British Association of Oral & Maxillofacial Surgeons as well as Officer of the Junior Trainees Group. He is a member of the Royal College of Surgeons of England and has taught oral and maxillofacial trainees for several years. He has presented papers nationally and internationally and has experience in organizing as well as chairing national and international conferences. Mr Kalantzis is co-author of the books Oxford Handbook of Dental Patient Care 2e and the Oxford Specialist Handbook of Medicine and Surgery for Dentists and is on the Editorial Board of Medical Problems in Dentistry 6e, and is a regular reviewer for journals such as Oral Oncology and British Journal of Oral & Maxillofacial Surgery. Tatiana Macfarlane BSc PhD MICR FHEA Senior Research Fellow University of Aberdeen, Dental School Aberdeen, UK Dr Tatiana Macfarlane is a Senior Research Fellow at the University of Aberdeen Dental School, UK. She previously worked at the University of Manchester in England, European Institute of Oncology in Italy and International Agency for Research of Cancer in France. Her main research interests are in epidemiology of head and neck cancer and oral health epidemiology. She has been involved in major international collaborations such as Alcohol-related Cancers and Genetic Susceptibility in Europe (ARCAGE) and International Head and Neck Cancer Epidemiology Consortium (INHANCE). She is a Fellow of the Royal Statistical Society (RSS), Fellow of the Institute of Learning and Teaching in Higher Education (ILTHE), member of the International Epidemiological Association (IEA), member of the American Association for Cancer Research (AACR) and professional member of the Institute of Clinical Research (ICR). She has authored over 120 peer-reviewed papers. xii • Contributors Avril Macpherson BDS (Edin) FDS RCSEd MFDS RCSEd MSND RCSEd DipConSed (N’castle) PGCTLCP (Edgehill) FHEA Clinical Director Liverpool University, Dental Hospital Liverpool, UK Avril Macpherson was appointed Consultant/Honorary Senior Clinical Lecturer in Special Care Dentistry, Liverpool University Dental Hospital and School of Dentistry, in 2010. She is a member of the British Society of Disability and Oral Health Executive Committee, the Specialty Advisory Committee in Special Care Dentistry (RCSEng), the Specialty Advisory Board in Oral Medicine and Special Care Dentistry (RCSEd) and is a Regional Specialty Advisor in Special Care Dentistry (RCSEng). Avril teaches widely in conscious sedation and special care dentistry and is a member of teaching faculty of the Society for the Advancement of Anaesthesia in Dentistry and a Resuscitation Council Advanced Life Support instructor. She is a RCSEd examiner for MFDS and MSCD examinations. Jasmine Murphy BDS (Hons) MSt (Camb) MFGDP UK MFDS RCS (Edin) MFDS RCS (Eng) MRes (Manc) FDS RCS (Eng) FFPH Consultant in Public Health (Children and Young People, Sexual Health, Dental Public Health) Leicester City Council Leicester, UK Jasmine Murphy is a Consultant in Public Health at Leicester City Council and registered as a Specialist in Dental Public Health with the General Dental Council. Children in Leicester have been reported to have the worst level of dental health in England and therefore Jasmine established the Oral Health Promotion Partnership Board and is driving forward the implementation and mobilization of Leicester’s first Oral Health Promotion Strategy for pre-school children. Leicester’s dental public health programme ‘Healthy Teeth, Happy Smiles!’ is an early intervention programme that is modelled on Scotland’s ChildSmile. Jasmine also contributed to Public Health England’s ‘Commissioning Better Oral Health’ guidance, is a core member of the National Institute of Health and Care Excellence (NICE) Public Health Advisory Committee and is also currently contributing to NHS England’s Commissioning Guide on Paediatric Dentistry. Jasmine has also recently been invited to join the Editorial Board of Oral Diseases journal. Contributors • xiii Farhad B. Naini BDS (Guy’s) MSc (Lond) PhD (KCL) FDSRCS (Eng) MOrthRCS (Eng) FDSOrth.RCS (Eng) GCAP(KCL) FHEA Consultant Orthodontist Maxillofacial Unit Kingston Hospital and St George’s Hospital London, UK Dr Naini is the Consultant Orthodontist in the Maxillofacial Units at Kingston Hospital and St George’s Hospital, Chair of the multidisciplinary Cranio-OrbitoFacial Surgery Group and Research Lead for Dentistry and Orthognathic Surgery. He has over 80 peer-reviewed publications and is editor of major textbooks on orthodontics and orthognathic surgery. He is also author of the reference textbook Facial aesthetics: concepts and clinical diagnosis. Tim Newton BA PhD CPsychol AFBPsS CSci Unit of Social and Behavioural Sciences King’s College London, Dental Institute Guy’s Hospital London, UK Professor of Psychology as Applied to Dentistry and Honorary Consultant Health Psychologist at King’s College London Dental Institute, Tim has worked in the behavioural sciences in relation to dentistry for over 20 years, and his particular interests include the management of dental anxiety, interventions to enhance oral health related behaviour and the working life of the dental team. He has published over 250 peer-reviewed articles in scientific journals. Paul P. Nixon BDS FDSRCS (Eng) DDRRCR Consultant in Maxillofacial Radiology School of Dentistry Liverpool University, Dental Hospital Liverpool, UK Paul Nixon is Consultant in Maxillofacial Radiology in Royal Liverpool University Hospital, clinical lead in the Dental Radiology Department and is also a specialist in Oral Surgery. He is an honorary clinical lecturer of the University of Liverpool and has an honorary contract at Alder Hey Children’s Hospital. He has authored or coauthored 26 publications. He is on the council of the British Society of Dental and Maxillofacial Radiology where he is audit lead and is responsible for their website. He recently served as external examiner for the MSc in Maxillofacial radiology at King’s College London for 6 years, is an examiner for the MJDF examination of the Royal College of Surgeons of England and is a member of the Royal College of Radiologists. xiv • Contributors Will Palin BMedSc MPhil PhD FADM Biomaterials Unit, The School of Dentistry College of Medical and Dental Sciences University of Birmingham Birmingham, UK Will Palin is a Reader in Biomaterials at the School of Dentistry, University of Birmingham. With a background in materials science, his developmental research for both dental and wider medical applications has attracted grant funding from the EPSRC, BBSRC, NIHR, Ministry of Defence and various industrial partners. He has authored over 70 publications and six book chapters. He is Editor of the European Journal of Prosthodontics and Restorative Dentistry, Subject Editor for Biomaterials Adhesion, International Journal of Adhesion and Adhesives and Board Member for Journal of Biomaterials Applications, Dental Materials and Journal of Dentistry. Andrew Paterson LLM BDS (Hons) FDSRCPS DRDRCS (Edin) MRDRCS (Edin) Consultant in Restorative Dentistry, NHS Ayrshire and Arran; Honorary Clinical Senior Lecturer, University of Glasgow; Maxillofacial Unit The University Hospital Crosshouse Kilmarnock, UK Andrew Paterson is a Consultant in Restorative Dentistry mainly involved in the prosthodontic management of head and neck cancer, trauma and hypodontia patients in a District General Hospital. Formerly an NHS Consultant at Glasgow Dental Hospital with 20 years’ experience in a private specialist restorative and prosthodontics referral practice dealing with all aspects of restorative dentistry. Part-time associate dento-legal adviser with an indemnity insurer. Contributor to all previous editions of this textbook. Crispian Scully CBE PhD MD MDS MRCS FDSRCPS FFDRCSI FDSRCS FDSRCSE FRCPath FmedSci FHEA FUCL FSB DSc DChD DMed (HC) Dr HC Emeritus Professor University College London London, UK Professor Crispian Scully is a Director of the WHO Collaborating Centre in Oral Health-General Health; journal Founder and Editor of Oral Oncology and Oral Diseases; and author or editor of 50 books, 200 book chapters and over 1000 papers on MEDLINE. He is UCL Professor Emeritus, has been Dean at UCL and Bristol, and president of several international and UK societies and has medals from Universities of Helsinki, Santiago de Compostela and Granada; Fellowship of UCL; and Doctorates from Universities of Athens, Granada, Helsinki and Pretoria. Contributors • xv John C. Steele MB ChB BDS MFDS RCSEd FDS (OM) RCSEd Dip Oral Med PGCTLCP FHEA Consultant and Specialist in Oral Medicine The Leeds Teaching Hospitals NHS Trust; Honorary Senior Lecturer in Oral Medicine Faculty of Medicine & Health University of Leeds Leeds, UK Dr John C. Steele is dual qualified in both medicine and dentistry and is currently Consultant, Honorary Senior Lecturer and Specialist in Oral Medicine based in Leeds. He has previously worked in a number of medical and surgical posts including emergency medicine. He has co-authored 14 articles published in peer-reviewed journals and has reviewed manuscripts for five national and international dental and medical journals. He is a current member of Council of the British Society for Oral Medicine. Damien Walmsley PhD MSc BDS FDSRCPS The School of Dentistry College of Medical and Dental Sciences University of Birmingham Birmingham, UK Professor Walmsley is a recognised both for his research and teaching. His research is on the the use of ultrasonics in dentistry including its use in periodontology, endodontics and its healing effects in repairing teeth. His present research funding includes imaging biofilm and observing its real time removal via ultrasonic instruments. He is very active in Interdisciplinary doctoral training centres at the University of Birmingham and is Graduate Director for Dentistry. He publishes his work in high impact scientific journals which has resulted in research and advisory roles for all the major dental companies. He is a well respected educator in Prosthodontics and also contributes to courses on Information Technology and Law/ethics courses. Clinically his work evolves around Prosthodontics and he is the leader of a busy NHS department. He is Scientific Advisor to the British Dental Association and enjoys a high profile in the media. He is a past President of the British Prosthodontic Society. International roles include Past President of the Association for Dental Education in Europe and deputy chair of U21 Health Sciences. Editorial duties include past Editor of the Journal of Dentistry and he is on the Editorial boards of the BDJ, European Journal of Dental Education, Journal of Dental Education, Journal of Endodontics. European Journal of Restorative Dentistry and Dental Update. xvi • Contributors Richard Welbury Professor of Paediatric Dentistry School of Dentistry University of Central Lancashire Preston, UK Richard Welbury is Professor of Paediatric Dentistry at the University of Glasgow Dental School and currently Dean of the Dental Faculty and VicePresident of the Royal College of Physicians and Surgeons of Glasgow. Paul H.R. Wilson BSc BDS MSc FDSRCPS FDS(RestDent) DipDSed Consultant in Restorative Dentistry Oxford University Hospitals NHS Foundation Trust, Headington, Oxford UK The Circus Dental Practice Bath, UK Paul H.R. Wilson is Consultant in Restorative Dentistry at Oxford University Hospitals NHS Foundation Trust and he works in private specialist dental practice in Bath. He is visiting Senior Clinical Lecturer at the Universities of Aberdeen and Bristol. He completed postgraduate training at Guy’s & St Thomas’ Hospitals, London and King’s College London. Graeme Wright BDS FDS(Paed Dent) RCPSG MPaed Dent RCSEd PGCLTHE FHEA Consultant in Paediatric Dentistry Royal Hospital for Sick Children Edinburgh, UK Graeme Wright is Consultant in Paediatric Dentistry at Edinburgh Royal Hospital for Sick Children. He is an Executive Board member of BSPD, organizer of the IAPD 2015 International Congress and editorial board member of ‘Dental Traumatology’. His sub-specialty interests are Dental Traumatology and Oncology/Haematology related to dentistry. Contents Preface to the Fourth Edition Contributors 1. Dental public health, epidemiology and prevention Tatiana Macfarlane, Jasmine Murphy v vii 1 2. Social and psychological aspects of dental care Tim Newton 27 3. Dental disease Crispian Scully 39 4. The dental team Crispian Scully, John Cameron 71 5. Law, ethics and quality dental care John Cameron 93 6. Practice management Fiona Cox, Martyn Cox 121 7. History and examination Mark Griffiths 167 8. Dental and maxillofacial radiology Paul Nixon 175 9. Pain and anxiety management Avril Macpherson 201 10. Drug prescribing and therapeutics Mark Griffiths 223 11. Dental materials William Palin, Damien Walmsley 237 xviii • Contents 12. Implantology Stephen Barter, Nikos Donos 269 13. Oral medicine David H. Felix 289 14. Oral and maxillofacial surgery Athanasios Kalantzis 337 15. Orthodontics Daljit Gill, Farhad Naini 391 16. Paediatric dentistry Graeme Wright, Richard Welbury 429 17. Periodontology Iain Chapple 461 18. Removable prosthodontics Andrew Paterson 475 19. Operative dentistry Paul H.R. Wilson 513 20. Special care dentistry Avril Macpherson 577 21. Emergencies John Steele 621 Appendices Appendix A: Average dates of mineralization and eruption of the primary dentition Appendix B: Tooth notation Appendix C: Tooth eruption 637 Index 643 638 640 640 Dental public health, epidemiology and prevention Dental public health 1 Oral health epidemiology 3 The prevention of oral diseases 4 The wider determinants of health 5 Oral health promotion 6 Common risk factors 6 Barriers to healthy behaviours 7 Changing disease levels 8 Caries risk 9 Diet and dental caries 10 Fluoride 12 Modes of action 12 Smoking and oral health 16 Smokeless tobacco and oral health 17 Electronic cigarettes and oral health 18 1 Hookah (shisha) and oral health 19 Alcohol consumption and oral health 19 Other substance abuse and oral health 21 HIV infection and oral health 21 Prevention of dental neglect 22 Sport trauma 23 Temporomandibular disorders 23 Frequency of dental attendance 23 Routine scale and polish 23 Prevention in older patients 24 Pregnancy and oral health 25 Oral health in special population groups 25 Conclusion 26 Dental public health Definition This is a non-clinical specialty involving the science and art of preventing oral diseases, promoting oral health to the population rather than the individual. It involves the assessment of dental health needs, developing policy and strategy and ensuring appropriate dental health services to meet the needs of the population. Dental Public Health (DPH) is concerned with the oral health of a population rather than individuals and has been defined as the science and art of preventing oral diseases, promoting oral health and improving the quality of life through the organized efforts of society. Dental public health practice requires an understanding of the challenges in the delivery, planning and management of health services in order to ensure that the provision of health services meets the needs of the population. This dental specialty requires specific skills in undertaking oral health needs assessments and developing specific oral health policies and strategies that protect and promote 2 • C L I N I C A L D E N T I S T RY population level oral health. It also involves a comprehensive understanding and appreciation of the principles and methods that underpin oral health promotion, oral health inequalities, the wider determinants of health and health behaviour. Oral health has improved in the UK over the last 30 years, but there is evidence that inequalities have widened. With limited funding and the ever-growing evidence base for interventions, dental public health specialists must make decisions, develop policies and implement strategies that are based on the best available scientific evidence in order to meet oral health goals, reduce oral health inequalities and sustain necessary resources. Such activities also involve the systematic use of data and information systems, application of programme planning frameworks, engagement with the communities in the decision-making process, conducting sound evaluation and disseminating lessons that have been learnt. The evidence-based decision-making process which is applied in dental public health integrates best available research evidence, practitioner expertise and other available resources including the characteristics, needs, values and preferences of those who will be affected by the intervention. Once health needs are identified through a community assessment, the scientific literature can identify programmes and policies that have been effective in addressing those needs. However, the amount of available evidence can be overwhelming. There are many types of evidence (e.g. randomized controlled trials, cohort studies, qualitative research) and the best type of evidence depends on the question being asked. Not all types of evidence (e.g. qualitative research) are equally represented in reviews and guidelines. The concept of a ‘hierarchy of evidence’ can be problematic when appraising the evidence for public health interventions as not all populations, settings and health issues are necessarily represented in evidence-based guidelines and/or systematic reviews. An important objective for those engaged in evidence-based dental public health is to improve the quality, availability and use of evidence in public health decision-making. The wide-scale implementation of evidence-based dental public health requires not only a workforce that understands and can implement the evidence base for dental public health efficiently but also sustained support from health department leaders, practitioners and policy makers. Evidence-based practice guidelines are based on systematic reviews and/or meta-analyses of research-tested interventions and can help practitioners select interventions for implementation. • Systematic reviews use explicit methods that focus on a particular research question which locates and critically appraises all high quality research evidence relevant to that question. They result Dental public health, epidemiology and prevention • • 3 in reports and recommendations that summarize the effectiveness of particular interventions, treatments or services and often include information about their applicability, costs and implementation barriers. Meta-analysis is a statistical technique to combine pertinent data from several studies to develop a single conclusion that has greater statistical power. The benefits of meta-analysis include a consolidated and quantitative review of the large, complex and sometimes conflicting body of literature. The Cochrane Library (http://www.cochranelibrary.com) is an online collection of databases that contain different types of highquality, independent evidence to inform healthcare decision-making. The Centre for Evidence-based Dentistry (CEBD; http://www.cebd.org) sets out an approach to systematizing the evidence for different research questions, with the highest level of evidence being systematic reviews and randomized clinical trials, with case series and expert opinion as the lowest level of evidence. To find evidence tailored to their own context, practitioners may need to search resources that contain original data and analysis. Peer-reviewed research articles, conference proceedings and technical reports can be found for example in PubMed (http://www.ncbi .nlm.nih.gov/pubmed). Maintained by the US National Library of Medicine, PubMed is the largest and most widely available bibliographic database of biomedical literature. Oral health epidemiology Epidemiology, which is defined as the study of disease distribution and its determinants in specified populations, is the basic science of public health because it studies the patterns, causes and effects of health and disease conditions in human populations. It is the cornerstone of public health and informs policy decisions and evidencebased practice by identifying risk factors for disease and targets for preventive health care. Furthermore, epidemiology has been used to generate much of the information required by public health professionals to develop, implement and evaluate effective intervention programmes for the prevention of disease and promotion of health, such as the eradication of smallpox, the anticipated eradication of poliomyelitis, and prevention of diphtheria, tetanus, measles, meningitis and mumps, heart disease and cancer. The ‘art’ of epidemiology is knowing when and how to apply the various epidemiological strategies to answer specific health questions. Such designs include descriptive epidemiological studies (such as cross-sectional or surveys) and analytical (such as cohort studies, case-control studies and randomized clinical trials). 4 • C L I N I C A L D E N T I S T RY Dental caries is a public health concern and collecting data on its prevalence, incidence and trends is an important field in oral health epidemiology. Definitions used include: • Prevalence: the proportion of individuals with disease (cases) in a population at a specific point in time. Incidence: the number or proportion of individuals in a population who experience new disease during a specific time period. Trend: the changes or differences in the prevalence or incidence of disease with respect to time. • • The prevention of oral diseases The major oral diseases – dental caries, periodontal disease and mouth cancer (see Chapter 3) – are not inevitable, but are to a large extent influenced by the wider determinants of health, i.e. psychosocial, economic, political, environmental, social and lifestyle factors. The aetiology of these conditions is increasingly well understood and prevention is largely possible if appropriate policies and strategies are in place which influence or assist people in adopting appropriate changes in behaviour. Prevention is defined in three stages: • • • Primary prevention – steps taken to ensure disease does not occur Secondary prevention – promoting early intervention in those already affected to halt progression at incipient stage of disease Tertiary prevention – treatment of well-established disease to restore function and avoid further episodes The prevention of oral diseases can also be regarded as measures applied either on a population basis, or at an individual level. Examples of measures applied on a population basis include water fluoridation and health promotion campaigns. Preventive measures on an individual basis can be applied either by a dental professional (e.g. fluoride varnish, fissure sealants, diet counselling, smoking cessation) or by the individual, e.g. tooth-brushing. In the developed world, dentistry has traditionally taken a ‘treatment-oriented’ approach, with the view that individuals were reliant on dental professionals for maintenance of oral health, but recent decades have seen a change to a more ‘preventive-oriented’ approach. Factors influencing this transition include: • • increased understanding of the nature of dental caries, periodontal disease and other oral diseases increased appreciation of the shortcomings of traditional restorative dentistry Dental public health, epidemiology and prevention • • increased evidence based on preventative approaches changing aspirations of patients (perhaps of importance). • 5 greatest The wider determinants of health Oral health and general health are determined by a complex interaction between individual characteristics, lifestyle and the physical, social and economic environment. People living in poorer areas tend to have worse oral and general health when compared to those living in more affluent areas. Given the close links between oral health and other indicators such as family income, there is increasing pressure to tackle the wider social determinants of health through the implementation of appropriate interventions. The wider social determinants of health (Figure 1.1) are the circumstances in which people are born, grow up, live, work, and age. These circumstances are in turn shaped by a wider set of forces: economics, social policies and politics. Oral health inequalities are the ‘differences in oral health status between different population groups’. Inequalities in oral health exist between social classes, countries within the United Kingdom and among certain minority ethnic and population groups. Oral health inequalities can only be reduced through the implementation of effective and appropriate oral health promotion policies and strategies which tackle the wider social determinants of health. The General socioeconomic, cultural and environmental conditions Living and working conditions Social and community networks Individual lifestyle factors • • • • Work environment Unemployment Education Healthcare services Individuals (age, gender and genetic factors) • Housing • Water and sanitation • Agriculture and food production Figure 1.1 Determinants of health (based on Dahlgren G & Whitehead M 1991 Policies and strategies to promote social equity in health. Institute for Future Studies, Stockholm (Mimeo). 6 • C L I N I C A L D E N T I S T RY improvements in oral health over the last 30 years have been largely a result of fluoride toothpaste and social, economic and environmental factors. Oral health promotion Health promotion is the process of enabling people to increase control over, and to improve their health (World Health Organization [WHO]). It moves beyond a focus on individual behaviour towards a wide range of social and environmental interventions. Health promotion describes activities and actions designed to enhance positive health and prevent ill-health by a combination of prevention, health education and health protection. There are a number of approaches that can be chosen when planning an oral health promotion initiative including: settings (e.g. nurseries, schools, care homes), population group (e.g. children, pregnant women, adults, vulnerable groups) and topic based (e.g. dental caries, periodontal disease, oral cancer). Prevention. Described above. Health education. Any combination of learning experiences designed to help individuals and communities improve their health by increasing their knowledge or influencing their attitudes (WHO). It involves the provision of information aimed at influencing beliefs, attitudes and behaviour relating to oral and dental health. In its widest sense, it also includes provision of information about access to and appropriate use of health services. The key messages for oral health (see Chapter 3) are: reduce the intake of sugar-containing food and drink, particularly the frequency of sugar consumption and avoid between-meal sugar snacks; brush teeth twice daily with a toothpaste containing fluoride; attend the dentist regularly; do not use tobacco; reduce alcohol consumption. Health protection. The practice of a nation to protect, improve and restore health of individuals in a community or entire populations. It functions through collective societal activities, programmes, services and institutions aimed at improving health of people. It comprises laws, regulations, policies and voluntary codes of practice aimed at preventing disease and enhancing health, e.g. legislation making use of car seat-belts compulsory, thereby reducing the prevalence of maxillofacial injuries due to road traffic accidents. Common risk factors Traditionally, there has been an emphasis on dental health education, either with individuals or groups, which has focused on imparting knowledge. It has been shown that conventional oral health Dental public health, epidemiology and prevention • 7 Risk conditions Risk factors Diet Diseases Obesity Risk factors Tobacco Cancers School Stress Heart disease Alcohol Respiratory disease Control Dental caries Workplace Exercise Periodontal disease Policy Hygiene Political environment Trauma Physical environment Injuries Housing Social environment Figure 1.2 Common risk approach. Reproduced from Watt RG, Sheiham S 2000 The common risk factor approach: a rational basis for promoting oral health. Community Dentistry and Oral Epidemiology 28(6):399–406 with permission from John Wiley. education is neither effective nor efficient (Kay and Locker, 1996), especially if these oral health programmes only concentrate on individual behaviour change and do not take into account the influence of socio-political factors as the key determinants of health. The common risk factor approach (Figure 1.2) takes a broader perspective and targets risk factors common to many chronic conditions and their underlying social determinants. The key concept of this approach is that concerted action against common health risks and their underlying social determinants will achieve improvements in a range of chronic health conditions more effectively and efficiently than isolated, disease-specific approaches. This approach acknowledges that many diseases have common predisposing risk factors to oral health. A poor diet that is high in sugars, and smoking are examples of behaviours which impact adversely upon oral as well as general health. As these causes are common to a number of other chronic diseases, adopting a collaborative approach is more rational than one that is disease specific. It also recognizes that engendering lasting changes in individual ‘lifestyle’ behaviours requires supportive social, economic and political environments. Barriers to healthy behaviours The principle of health education is that by provision of appropriate information and circumstances, beliefs and attitudes of individuals 8 • C L I N I C A L D E N T I S T RY Upstream Stop! Do not jump in ‘Causes of the causes’ General politics Midstream Help Help Social policy Public health policy + strategy Health promotion Health care and services Downstream Economy Life chances Lifestyle and environment Health Quality of life Figure 1.3 Upstream and downstream approaches. will be affected sufficiently to result in the adoption of behaviour likely to enhance health and diminish the chance of disease. However, dental disease is heavily influenced by socioeconomic and other constraints that may restrict the choices available. Whilst parents may realize that fresh fruit is preferable to chocolate bars, non-availability or price may preclude its provision. Similarly, sugar-containing foodstuffs are often given to children not only when they are hungry but also as a reward or a pacifier. The dominant preventive approach in dentistry, i.e. narrowly focusing on changing the behaviours of high-risk individuals, has failed to effectively reduce oral health inequalities, and indeed may have increased the oral health equity gap. A conceptual shift is needed away from this biomedical/behavioural ‘downstream’ approach, to one addressing the ‘upstream’ underlying social determinants of population oral health (Figure 1.3). Failure to change our preventive approach is a dereliction of ethical and scientific integrity (Public Health England, 2014). Changing disease levels Dental disease levels in the UK population have reduced significantly in the last three decades. Dental public health, epidemiology and prevention • 9 The 2009 Adult Dental Health Survey demonstrated that the proportion of edentulous adults fell dramatically from 30% in 1978 to 6% in 2009. However, the survey also showed that stark inequalities exist. For example, people from managerial and professional occupation households had better oral health (91%) compared with people from routine and manual occupation households (79%) (The Health and Social Care Information Centre, 2011). The 2013 National Children’s Dental Health Survey (Office for National Statistics, 2015) showed that there were reductions in the extent and severity of tooth decay present in the permanent teeth of 12 and 15 year olds overall in England, Wales and Northern Ireland between 2003 and 2013. Large proportions of children, however, continue to be affected by disease, and the burden of disease is substantial in those children that have it. In 2013, nearly a half (46 per cent) of 15 year olds and a third (34 per cent) of 12 year olds had “obvious decay experience” in their permanent teeth. This was a reduction from 2003, when the comparable figures were 56 per cent and 43 per cent respectively. Furthermore, nearly a third (31 per cent) of 5 year olds and nearly a half (46 per cent) of 8 year olds had obvious decay experience in their primary teeth. Untreated decay into dentine in primary teeth was found in 28 per cent of 5 year olds and 39 per cent of 8 year olds. Overall, 58 per cent of 12 year olds and 45 per cent of 15 year olds reported that their daily life had been affected by problems with their teeth and mouth in the past three months. Caries still affects a large number of children in lower socioeconomic groups and within some ethnic minorities, as do its sequelae (odontogenic infections; Chapter 3). There is a threefold difference in levels of caries between the least and most deprived communities. Upstream action addressing risks, beliefs, behaviours and the living environment by ensuring appropriate policies and strategies are in place are probably as important as affordable access to professional treatment. This follows the sentiment of the Marmot Review ‘Fair Society, Healthy Lives’, which dominates the wider public health agenda of tackling avoidable differences in health using an ‘upstream’ approach. An upstream approach is when trying to change people’s individual behaviours (such as encouraging the use of fluoride toothpaste with tooth brushing or adding fluoride to the water supply), leads to beneficial effects flowing ‘downstream’ in the reduction in dental treatment required due to a reduction in caries prevalence in the population. Caries risk The ability to determine susceptibility to dental caries on either a population or individual patient basis would offer a number of advantages. 10 • C L I N I C A L D E N T I S T RY Population basis. Permits developing appropriate policies and strategies which seek to target resources, the location of clinics and the implementation of preventive programmes. Individual basis. Determines the need for caries control measures such as socioeconomic factors, existing caries status, clinical judgement of dental professional, the timing of dental recall appointments, decisions as to suitability for advanced restorations, suitability for orthodontic treatment. Various tests have been devised for determining caries risk such as: • • counts of salivary lactobacilli (Dentocult LB), mutans streptococci (Dentocult SM) tests of salivary buffering capacity (Dentobuff). These tests have met with limited success as, due to the multifactorial aetiology of dental caries, variation precludes accuracy and consistent estimation of the caries susceptibility of an individual patient at the chairside. The clinical judgement of the dental clinician, current caries experience and socioeconomic factors of the patients have proven the most reliable indicators of caries risk assessment. Determination of disease risk is an important factor in determining how frequently patients should attend for preventive dental care such as fluoride varnish applications, fissure sealants, etc. Diet and dental caries (see also Chapter 3) Evidence that sugar causes caries There is clear and extensive evidence of the relationship between the frequency and amount of sugar consumption and the prevalence and severity of dental caries: • • • • • epidemiological data show a correlation between sugar consumption and caries on a national basis caries prevalence is higher in communities with high sugar intake, e.g. sugar cane and confectionery industry workers caries prevalence increases following introduction of a sugarcontaining diet in isolated communities, e.g. the Inuit, island communities such as Tristan da Cunha experimental clinical studies (such as Vipeholm Study) investigating the relationship between sugar intake and dental caries show positive correlation between consumption of sugar (between meals and at meals) and caries increment caries decreases following restriction of sugar, e.g. wartime diets. Recently a number of research papers have argued that the increased availability of fluoride has lessened the impact of sugar in the aetiology of dental caries. However, there can be little doubt that a diet rich Dental public health, epidemiology and prevention pH • 11 Plaque pH Critical pH 5.5 Net loss of calcium and phosphate ions below critical pH Safe zone Danger zone 6 Bottle 7 8 Breakfast 9 10 11 Snack Sippy cup Sippy cup 12 Lunch Figure 1.4 The effect of repeated sugar consumption. in sugar, particularly if consumed at frequent intervals, will result in caries development. Factors influencing cariogenicity of foods Cariogenic potential is related to consistency: sticky retentive foods are more cariogenic than liquid non-retentive forms, e.g. toffee is more cariogenic than chocolate. The frequency of consumption is crucial. Snacking or ‘grazing’ results in plaque pH being below the point where net outflow of calcium and phosphate ions from the tooth surface occurs for prolonged periods (Figure 1.4). Dietary advice The factors related to changing behaviour are particularly important in encouraging patients to adopt a less cariogenic diet. Effective dietary counselling requires knowledge of a patient’s habits relating to non-milk extrinsic sugar consumption. Diet diary • • • • • • Useful for those with high caries experience Must encourage patient to complete accurately Should cover a 3-day period including either Saturday or Sunday When completed, analyse with patient; highlight cariogenic foodstuffs, particularly hidden sugars Allows formulation of personal advice for each individual Where possible, advise patient (and parent) in both written and verbal form. The ultimate message is ‘eat less sugar and eat sugar less often’. 12 • C L I N I C A L D E N T I S T RY Non-sugar sweeteners. Non-cariogenic and useful sugar substitutes. Bulk sweeteners, e.g. sorbitol and xylitol, provide calories and bulk; useful as sugar substitutes in confectionery, chewing gum and medicines. Intense sweeteners, e.g. saccharin and aspartame are calorie free; popular in ‘slimmers’ foods’. From a dental point of view, whilst bulk and intense sweeteners are non-cariogenic and therefore useful sugar substitutes, use of artificial sweeteners also perpetuates the craving for sweet foods. ‘Tooth-friendly’ sweets. Identified by the ‘tooth-friendly’ logo, these sweets contain non-sugar sweeteners. Their use should be restricted in small children due to possible adverse effects on the gastrointestinal system (e.g. diarrhoea). Chewing-gum. Sugar-free chewing-gum stimulates saliva and thus increases salivary buffers and enhances washout of sugar. May be of benefit in some patients, but should not be viewed as a prime cariespreventive measure. Carbonated beverages. Carbonated drinks have a pH of 2–3 and can cause marked loss of tooth structure via erosion – an increasing problem in teenagers. Even ‘diet’ varieties can lead to erosion. Detersive foodstuffs. Contrary to previous beliefs, detersive foods are of little or no benefit in removal of plaque. Effective plaque removal is dependent on tooth-brushing. However, carrots, apples, etc. are preferable to high-sugar snacks. Fluoride Evidence for the efficacy of fluoride in the prevention of dental caries is incontrovertible. A series of systematic reviews published by the Cochrane Library have concluded that children who brush their teeth at least once a day with toothpaste that contains fluoride will have less tooth decay. These reviews have also shown that fluoride has a caries preventive action when delivered in vehicles other than toothpaste. Public Health England (PHE) has published a report ‘Water fluoridation health monitoring report for England 2014’. The report provides further reassurance that water fluoridation is a safe and effective public health measure. PHE continues to keep the evidence base under review. Modes of action Systemic (pre-eruptive) effect. Fluoride ions are incorporated into enamel structure in the form of fluor-apatite during tooth formation. This decreases the mineral solubility. Dental public health, epidemiology and prevention • 13 Topical (post-eruptive) effect. Fluoride ions are associated with the tooth surface post eruption. The fluoride interaction with hydroxylapatite is complex; fluoride interacts with the tooth structure either by incorporation into the crystal lattice or by binding to crystal surfaces. Calcium fluoride at the tooth surface not only reduces the solubility of the apatite but also encourages remineralization. Whilst fluoride may also cause decreased acid production by cariogenic bacteria, its effect on mineral solubility is of much greater clinical significance. Historically it was thought that fluoride availability during tooth formation for incorporation into the hydroxyl-apatite was most important. It is now realized the topical effect at the tooth surface post eruption is very important. Thus, methods that apply fluoride on a regular (daily) basis are most effective against caries. Evidence that fluoride prevents caries • • • • • Caries prevalence is lower in areas where fluoride is present naturally in the water supply at the optimum level of 1 ppm (part per million). Addition of fluoride to the water supply to the optimum level of 1 ppm is effective in reducing the prevalence of dental caries. Fluoride-containing toothpastes are effective in preventing caries. Fluoridated milk is beneficial to school children, especially their permanent dentition Supervised regular use of fluoride mouth-rinse is associated with a reduction in caries increment in children. Mechanisms for delivering fluoride Water fluoridation Fluoridation of the public water supply at 1 ppm has been shown in numerous studies to reduce caries incidence. It is more effective against caries on smooth surfaces of teeth than in pits and fissures. However, in the UK, despite its proven benefits and safety, only 10% of the population receive fluoridated water. Fluoride toothpaste The main mechanism whereby fluoride is delivered is via toothpaste (dentifrice). Most formulations contain sodium fluoride (NaF) or sodium monofluorophosphate (SMFP) or a combination of both, at a concentration of either 1000 or 1500 ppm. Used twice daily, these can reduce caries incidence by around 30%. Restrict the amount of toothpaste used by children under the age of three to a smear of toothpaste at each brushing. The amount of toothpaste can be increased to a pea-sized amount for children aged three to six years. 14 • C L I N I C A L D E N T I S T RY Children’s formulations containing either 125 or 550 ppm F− are available, but there is little evidence that at this concentration these formulations are truly effective in preventing caries, particularly in high-risk children, and therefore they are not recommended. Children under the age of three years should be using fluoridated toothpaste with at least a minimum of 1000 ppm F− and those over the age of three should be using more than 1000 ppm F−. All children over the age of six and all adults should be recommended to use fluoridated toothpaste with at least 1350 ppm fluoride. For those 10+ years with active caries and at continual high risk, 2800 ppm fluoride toothpaste can be prescribed by dentists. For those 16+ years with active disease and at continual high risk, dentists can prescribe either 2800 ppm or 5000 ppm fluoride toothpaste. Toothpastes are available in mild minty taste or fruity flavours but mint flavours are preferred in order to discourage children from eating the paste. Fluoride drops and tablets Given during the period of tooth formation, fluoride drops and tablets can exert both a systemic and topical effect. Dosage is related to age and the fluoride content of the local water supply. The regimen currently recommended in the British National Formulary (BNF) is shown in Table 1.1. Give fluoride tablets last thing at night and allow to dissolve slowly in the mouth. If using fluoride toothpaste, any additional supplementation is required only in those judged at high risk of developing caries. However, to be effective, supplements must be given over a prolonged period and compliance can be problematic. Fluoridated salt Fluoridated salt has been used successfully as a caries preventive measure in Switzerland and France. However, given the general TABLE 1.1 Recommended daily dosage of fluoride tablets and drops (mg F/day), related to age and concentration of fluoride in the drinking water Age Water F (ppm) <0.3 Water F (ppm) 0.3–0.7 Water F (ppm) >0.7 0–6 months 0 0 0 6 months–3 years 0.25 0 0 3–6 years 0.5 0.25 0 Over 6 years 1 0.5 0 Dental public health, epidemiology and prevention • 15 health promotion message of decreased salt intake and the fact that most salt is added during the manufacturing process, this is unlikely to be a realistic mechanism for community fluoridation. Fluoridated milk/fruit juices Whilst proven to be successful vehicles for fluoride delivery, these are difficult to implement as a public health measure. A recent systematic review concluded that while there were insufficient studies with good quality evidence examining the effects of fluoridated milk in preventing dental caries, the included studies suggested that fluoridated milk was beneficial to school children, especially their permanent dentition. The data need to be supplemented by further RCTs (randomized controlled trials) to provide the highest level of evidence for practice. The disadvantage of fruit juices is that they are acidic. Fluoride gels Topically applied in individual trays. Given current views on the importance of the frequency of fluoride application, if fluoride therapy is required in addition to toothpaste, mouthwashes are preferred. Fluoride mouthwashes Most contain NaF at 0.05% for daily use or 0.2% for weekly use, although daily use is preferred. Patients should be advised to use fluoride mouth rinse at a different time to brushing. Indications. Teenagers with high caries activity; patients prone to root caries, e.g. xerostomia; non-carious tooth surface loss; dentine hypersensitivity. However, there is some concern and evidence that alcohol-containing mouthwashes may be carcinogenic. Fluoride varnishes Contain F− in an alcoholic solution of natural varnishes at 2.2% NaF (Duraphat®). Fluoride varnishes applied professionally two to four times a year have the ability to substantially reduce tooth decay in children. Fluoride varnish is one of the best options for increasing the availability of topical fluoride, regardless of the levels of fluoride in the water supply. A number of systematic reviews conclude that applications two or more times a year produce a mean reduction in caries increment of 37% in the primary dentition and 43% in the permanent. Fluoride foams Used in a similar form to fluoride varnishes, these are professionally applied to promote remineralization of early enamel caries and to encourage remineralization of exposed dentine. 16 • C L I N I C A L D E N T I S T RY Fluorosis Fluorosis or mottled enamel may occur due to excessive intake of fluoride during tooth formation. In the UK, fluorosis is most likely to occur due to excessive consumption of fluoridated toothpaste. For this reason, it is vital that the volume of toothpaste used by children should be restricted to a pea size/smear amount (according to age) at each brushing and children discouraged from swallowing paste. Fluorosis results in hypomineralization and affects mainly the permanent dentition. Effects range from barely noticeable ‘white flecks’, to brown stains in more severe cases. Mild forms may diminish with time but can be markedly improved by etching and polishing. Most severe cases may require veneers. Safety of fluoride The safety of fluoride at 1 ppm in the public water supply has been the subject of numerous studies and has been established. However, acute toxicity (particularly from the ingestion of fluoride toothpaste) may occur above 5 mg F−/kg body weight. Antidote. <5 mg F−/kg body weight – drink large volume of milk and seek medical advice; >5 mg F−/kg body weight – refer to hospital for gastric lavage without delay. Fluoride tablets, toothpaste and mouthwashes should always be stored and kept out of the sight and reach of children or people with learning impairment. Smoking and oral health The adverse impact of smoking on health is well recognized. Smoking can have many adverse effects on oral health (Box 1.1). Cigarette smoking is the greatest single cause of illness and premature death in the UK: about 100 000 people in the UK die each year due to smoking. Long-term smokers, on average, have life expectancy about 10 years less than non-smokers. Worldwide, tobacco use causes more than 5 million deaths per year and current trends show that tobacco use will cause more than 8 million deaths annually by 2030. Prevalence of smoking may be decreasing in some people in the developed world but is increasing in the developing world. Stopping smoking has significant benefits both for general and oral health. The dental team has a key role to play in helping smoking cessation. As smoking has such a dramatic effect on the patients’ oral health, the most effective way of ensuring they can access local stop smoking services is to give very brief advice (30 seconds). ‘Ask, Advise Dental public health, epidemiology and prevention • 17 Box 1.1 The effects of smoking on oral health • • • • • • • • • • • • • • • There is a dose–response relationship between tobacco use and risk of mouth cancer There is some evidence that stopping smoking after diagnosis improves mouth cancer survival White patches occur on the oral mucosa six times more frequently in smokers than non-smokers Smoking causes cellular changes within the oral epithelium, which most commonly presents clinically as smokers’ keratosis Smokers are 2.5 to 5 times more likely to develop periodontal disease than non-smokers. These odds may be even higher in younger people There is evidence of a direct correlation between the number of cigarettes smoked and the risk of developing periodontitis Reduced gingival redness and oedema in smokers (due to the vasoconstrictive effects of nicotine) may mask underlying attachment loss Acute necrotizing ulcerative gingivitis occurs predominantly in smokers Sinusitis occurs 75% more frequently in smokers than in non-smokers Taste and olfactory senses are dulled in smokers Tooth staining is more common in smokers Smokers are predisposed to halitosis Wound healing is delayed in smokers – dry sockets occur more commonly in smokers Osseointegrated implants are significantly more likely to fail in patients who smoke The outcome of most forms of periodontal therapy, including root planing, flap surgery, guided tissue regeneration and local antimicrobial therapy, is less favourable in smokers than in non-smokers and Act’ will give them the best chance to successfully stop smoking (PHE 2014): 1. Establish and record smoking status (ASK) 2. Advise on the personal benefits of quitting (ADVISE) 3. Offer help by signposting to local stop smoking service (ACT) Follow-up of patients is important and the dental team is well placed to assist with this because of their ongoing and regular contact with patients (Figure 1.5). There is good evidence that Nicotine Replacement Therapy (NRT) in the form of patches, chewing-gum and nasal sprays increases the quit success rates. Other drugs, such as bupropion and varenicline, may also help smokers quit. Smokeless tobacco and oral health Smokeless tobacco (ST) products are those that are chewed, sucked or inhaled. There is no scientific evidence that using ST either helps a person quit smoking or is a safer alternative to smoking. ST contains carcinogens, and therefore increases the risk of mouth cancer, 18 • C L I N I C A L D E N T I S T RY Precontemplation Maintenance Action Contemplation Preparation Figure 1.5 Stages of behavioural changes. potentially malignant disorders and gingival recession. Many forms of ST also contain sugar and its use is associated with tooth discoloration and halitosis. The use of ST is particularly common amongst south Asian communities (e.g. people with ancestral links to Bangladesh, India, Nepal, Pakistan or Sri Lanka), in particular chewing tobacco which is either chewed alone or with betel quid/paan. NICE has published guidelines on ST cessation in South Asian communities (https://www.nice.org .uk/guidance/ph39). The recommendations were developed by the Public Health Interventions Advisory Committee (PHIAC) and are based on the best available scientific evidence. Dental professionals have a crucial role to play in raising awareness of the dangers to oral health associated with the use of ST and should ensure the very brief advise ‘Ask, Advise and Act’ is also implemented for these patients as local stop smoking services will usually also help these patients quit, too. Electronic cigarettes and oral health E-cigarettes, short for electronic cigarettes, are battery-powered devices that look like conventional cigarettes, but more commonly look very different, as the technology develops. E-cigarettes provide doses of vaporized substances to the user in an aerosol form. The devices contain a heating element that vaporizes a liquid solution. Depending on the brand of e-cigarettes, the liquid solutions may contain nicotine and flavourings. Whilst e-cigarettes are certainly much lower in the amount of toxins that they contain compared to a standard cigarette, they are certainly not free of all chemicals. The overall effect of e-cigarette use Dental public health, epidemiology and prevention • 19 on public health is estimated to be at least 95% less than smoking tobacco cigarettes (Public Health England 2015). There is also no current evidence that e-cigarette emissions cause any significant environmental harm to others. There is little documented evidence regarding the oral effects of e-cigarette use. Systemic effects of e-cigarette use need further research. Hookah (shisha) and oral health A hookah (also known as a water pipe, nargeela, shisha, okka, kalyan, ghelyoon or hubble-bubble) is a device for smoking. The hookah operates by water-filtration and indirect heat. It is commonly used in peoples from the Arabian Peninsula, Turkey, India, Pakistan and some regions of China, and is becoming more popular in younger generations with the establishment of special bars in the UK and elsewhere. Hookah smoking is often considered a safe and harmless alternative to cigarette smoking. As a result more and more people are smoking shisha, particularly students and people in higher education. Smoking through water, using flavoured tobacco and at lower temperatures does not mean that water-pipe smoking is harmless. Hookah smoking (including flavoured products) causes raised carbon monoxide in the atmosphere (CO) and in blood levels (COHb) that are known to be harmful in cigarette smoking and can cause cardiovascular disease, respiratory problems and have an effect on those who are in the same environment. Sharing nozzles can also contribute to spread of infections. At the moment there is no national policy to raise awareness about hookah smoking and many people do not understand that it may have a harmful effect on their own and other people’s health around them. It is important that dental practitioners help to dispel myths about shisha’s alleged safety as it can cause mouth cancer and infections. Alcohol consumption and oral health High alcohol intake is associated with an increased risk of developing mouth cancer, potentially malignant disorders, periodontal disease, caries and xerostomia. Used in combination, alcohol and tobacco exert a synergistic effect that substantially increases the risk for mouth cancer. Alcoholism may lead to trauma, and can damage the liver and bone marrow resulting in excessive bleeding during dental treatment. Dental anaesthetics may not work as well in the alcohol abuser and may be carried into the bloodstream more rapidly, requiring additional injections. Both the Royal College of General Practitioners and NICE (the National Institute for Health and Care Excellence) recommend that 20 • C L I N I C A L D E N T I S T RY primary medical practitioners screen all patients for alcohol misuse using a questionnaire. It has been suggested that a similar type of questionnaire could be asked by a dentist (Figure 1.6). Typical questions might be: • • How often do you have a drink containing alcohol? How many units of alcohol do you drink on a typical day? Please tell us about your alcohol consumption Unit scoring system Questions (please circle your answers) 0 1 2 3 4 Never Monthly or 2 – 4 times 2 – 4 times (go to Page 4) per month per week less How often do you have a drink containing alcohol? How many units of alcohol do you drink on a typical day when you are drinking? 1–2 3–4 How often have you had 6 or more units if female, or 8 or more if male, on a single occasion in the last year? Never Less than monthly How often during the last year have you found that you were not able to stop drinking once you had started? Never How often during the last year you failed to do what was normally expected from you because of your drinking? 7–9 10+ Monthly Weekly Daily or almost daily Less than monthly Monthly Weekly Daily or almost daily Never Less than monthly Monthly Weekly Daily or almost daily How often during the last year have you needed an alcoholic drink in the morning to get yourself going after a heavy drinking session? Never Less than monthly Monthly Weekly Daily or almost daily How often during the last year have you had a feeling of guilt or remorse after drinking? Never Less than monthly Monthly Weekly Daily or almost daily How often during the last year have you been unable to remember what happened the night before because you had been drinking? Never Less than monthly Monthly Weekly Daily or almost daily Have you or somebody else been injured as a result of your drinking? No Yes, but not in the last year Yes, during the last year Has a relative or friend, doctor or other health worker been concerned about your drinking or suggested you cut down? No Yes, but not in the last year Yes, during the last year 1 Unit 1.5 Units Normal beer half pint (284ml) 4% Small glass of wine (125ml) 12.5% 2 Units Strong beer half pint (284ml) 6.5% Single spirit shot Alcopops bottle Normal beer (25ml) 40% (275ml) 5.5% Large bottle/can (440ml) 4.5% 3 Units 5–6 4+ times per week 9 Units Medium glass Strong beer Bottle of wine of wine Large bottle/can (750ml) 12.5% (175ml) 12.5% (440ml) 6.5% 30 Units Bottle of spirits (750ml) 40% Large glass of wine (250ml) 12.5% Figure 1.6 Alcohol units scoring system. Adapted from http://www .alcohollearningcentre.org.uk/_library/AUDIT-C.doc with permission from Alcohol Learning Centre, Public Health England. Dental public health, epidemiology and prevention • • • • 21 How often do you have six or more units of alcohol in a single day? In the last year, have you failed to do something that you would normally do because of drinking too much alcohol? How often in the last year were you unable to remember what happened the previous night because of drinking too much alcohol? Scoring systems provided with the questionnaires would help dentists identify patients at risk who would benefit from intervention. Dental professionals could provide these patients with motivational advice and information leaflets. Those with more severe alcohol misuse would be referred to the patient’s medical practitioner. Other substance abuse and oral health Stimulants like ecstasy, amphetamines and cocaine are known to cause individuals to clench and grind their teeth, resulting in tooth wear, temporomandibular disorders, loose and cracked teeth and damage to the tooth roots and gums. Users of stimulants often also experience chronic dry mouth resulting in increased consumption of sugary drinks. Many drugs cause users to crave sweet foods but their lifestyle often ignores the importance of oral care. Methamphetamine causes the saliva glands to stop producing saliva resulting in an extremely dry mouth and enamel damage (‘meth mouth’). Heroin is known to cause serious oral health problems and in chronic longterm users, carious and missing teeth and periodontal disease are often evident. Dental practice setting has the potential to provide prevention of substance abuse through patient counselling on the hazards of drugs; this is most likely to occur when a problem already appeared to be present. It is also important to liaise with the patient’s medical practitioner if the patient has been prescribed methadone as a substitute for heroin: to ensure that the methadone being prescribed is sugar-free. Opioids are analgesics that have potential for misuse, abuse or addiction. As prescribers, dentists can minimize the potential for misuse or abuse through use of peer-reviewed guidelines for analgesia, patient education, careful patient assessment and referral for substance abuse treatment when indicated. HIV infection and oral health Oral problems can be common in people with HIV/AIDS, and the majority of oral conditions arise because of the immune defects. Oral disease is often the first manifestation of HIV infection. People with HIV are more susceptible to oral warts (which can also progress to 22 • C L I N I C A L D E N T I S T RY mouth cancer), herpes (‘cold sores’), oral hairy leukoplakia; candidiasis (thrush), ulcers and periodontal disease (periodontitis and gingivitis). In addition, bacterial infections that begin in the mouth can become more serious and, if not treated, spread into the bloodstream. This can be particularly dangerous for people living with HIV/AIDS who may have compromised immune systems. People with HIV/ AIDS may also experience dry mouth, which increases the risk of caries and candidiasis and can make chewing, eating, swallowing, and even talking difficult. Some HIV medications can cause dry mouth. Therefore dental practitioners must stress good oral hygiene, if necessary establish a plan for regular visits for oral examinations and periodontal therapy and treatment plan for dry mouth. In some countries, for example in the USA, some dental practitioners offer oral HIV tests on saliva. Prevention of dental neglect Dental neglect is a proxy indicator of broader neglect. Dental neglect is the wilful or persistent failure to meet a child’s or vulnerable person’s basic oral health needs by not seeking or following through with necessary treatment to ensure a level of oral health that allows function and oral health (freedom from pain and infection). Dental neglect can result in the impairment of oral or general health or development. Roles of dental professionals in the accurate, timely assessment of children for dental neglect means that they are potential catalysts in securing a child’s overall safety and well-being. In 2009, NICE guidelines officially recognized dental neglect as a type of child neglect, something that raised the profile of child oral health on the public health agenda. The NICE recommendations are related to two aspects of dental neglect: 1. the parent’s persistent failure to obtain NHS treatment for their child’s dental caries when such NHS dental services were available, and 2. the possibility of child maltreatment due to an absent or unjustifiable explanation for a child’s oral injury. Supervised neglect by dental professionals is a situation where a patient’s oral health has been allowed to deteriorate over a period of time, despite regular attendances to the dental clinician who is responsible for the patient’s care and treatment. Some dental clinicians mistakenly believe that damage to a child’s deciduous dentition is not worth repairing, despite the fact that the consequences could include high morbidity and knowingly putting the child at risk of pain and suffering. Every dental professional has a duty of care to exercise a reasonable level of skill and competence, when treating each patient under their care. Failing to provide necessary treatment is one way in which Dental public health, epidemiology and prevention • 23 this duty of care can be breached; recommending or providing unnecessary treatment falls at the other extreme, but is still a breach of a clinician’s duty of care. Sport trauma Dentistry plays an important role in preventing serious injury to the mouth during contact sports by advising patients to take care and to wear mouthguards which help protect against injuries to the cheeks, gums, jaws and teeth. Temporomandibular disorders Local mechanical factors such as teeth grinding may play an aetiological role in the development of temporomandibular disorders (TMD). Dentists should note evidence of toothwear and advise patients on measures to prevent trauma and bruxism. Night mouthguards can be prescribed to prevent future tooth wear (see Chapter 18; removable prosthodontics). Frequency of dental attendance An important consideration in the prevention of oral disease is the frequency with which patients should attend for a routine oral examination, or ‘check-up’. Traditionally patients were advised to visit the dentist on a 6-monthly basis. Currently there is no evidence to support or refute the practice of encouraging patients to attend for dental check-ups at 6-monthly intervals. However, it is recognized that patients differ in their risk of oral disease, and as oral health improves, a ‘one size fits all’ recall interval is no longer appropriate. Recall intervals should therefore be tailored to individual patients’ needs or circumstances. In England, NICE has issued guidance on the timing of dental recalls. This recommends that the interval between oral health reviews should be determined specifically for each patient and tailored to individual needs based on an assessment of disease levels and risk of or from dental disease. For patients younger than 18 years, recall intervals can vary between 3 and 12 months. For those over 18 years, intervals can range between 3 and 24 months. A guiding principle in deciding on recall intervals is to start with a short interval and then gradually increase if the patient’s oral health remains stable and risk factors remain constant or reduce. Routine scale and polish Currently there is insufficient evidence of clinical effectiveness and cost effectiveness of ‘routine scaling and polishing’ and the ‘optimal’ 24 • C L I N I C A L D E N T I S T RY frequency at which it should be provided for healthy adults. However some positive effects of dental scaling are found for chronic periodontal disease. As the magnitude of differences between 3-monthly and annual scaling after one year in published literature is small, evidence confirming these findings in the general dental population is required before a change in policy on dental scaling interval can be recommended. Prevention in older patients As oral health improves, an increasing number of older patients will retain their teeth for longer. In addition, demographic changes have seen the total number of people of pensionable age in the UK increase by 4.2% between 1985 and 2001. By 2025 this will have increased by 31.1%. Thus, care of the older patient is increasingly important to the dental profession. Furthermore, the independent review of NHS dental services in England (2009) also identified a growing population of older people who have experienced high levels of disease which have been treated by fillings and other restorations (the ‘heavy metal generation’) and who will have high maintenance needs as they age further. Factors complicating disease prevention in older patients Plaque control Gingival recession; migrated and tilted teeth increase the number of inaccessible surfaces. Partial dentures increase plaque retention. Poor eyesight and reduced dexterity make toothbrushing difficult. Polypharmacy is common in the older patient; some drugs reduce salivary flow. Diet Increased tendency to snacking – cakes and biscuits. Particularly prone to recurrent caries and root caries. Denture care Encourage removal of dentures at night and good denture hygiene. Emphasize the importance of annual dental examinations, even if edentulous, because this permits early detection of mucosal disease (e.g. mouth cancer). Advanced restorative care Improved quality of life at old age will demand tooth retention and consequently the need for restorative care. The growing older population may have acquired advanced restorative care such as crowns, Dental public health, epidemiology and prevention • 25 bridges and implants in their working age which requires maintenance in their older age (‘the heavy metal brigade’). Pregnancy and oral health Pregnant women require additional dental hygiene care due to hormonal changes which can affect oral health. Some pregnant women experience inflamed and bleeding gums, termed ‘pregnancy gingivitis’ which can start within the second month of pregnancy. Pregnant women are therefore more susceptible to developing periodontal disease during the time when hormonal fluctuations occur. Some women also experience a nodular inflammatory reaction on their gums known as a pregnancy granuloma. Dry mouth is another common complaint, but can be remedied by drinking plenty of water and using saliva stimulants available over the counter to stimulate saliva flow. Other oral health problems may include tooth erosion as a result of repeated gastric acid exposure from severe morning sickness. If pregnant women are experiencing severe and recurrent morning sickness, they should be advised to rinse the mouth afterwards with water or a fluoride mouthwash and wait for at least 30 minutes before toothbrushing. Women who suffer from morning sickness may also want to eat ‘little and often’ but should try to avoid sugary and acidic foods and drinks between meals to protect teeth against caries. It is a myth that calcium is lost from the mother’s teeth during pregnancy. The calcium a baby needs is provided by the mother’s diet. If dietary calcium were to be inadequate, however, the body accesses this mineral from bone stores. An adequate dietary intake of foods such as dairy products and green leafy vegetables will help to ensure sufficient calcium intake during pregnancy. Smoking and drinking in pregnancy can lead to an underweight baby and also affect the unborn baby’s dental health. Maternal smoking increases the risk of cleft lip/palate, as well as other birth defects, in the offspring. Maternal oral health may negatively affect pregnancy outcomes. Oral health in special population groups (see also Chapter 20) Patients in special population groups such as immunocompromised and hospitalized patients are at greater risk for general morbidity due to oral infections. Individuals with diabetes or inflammatory diseases such as rheumatoid arthritis and ankylosing spondylitis are at greater risk for periodontal disease and therefore require additional preventative measures. There may be an association between 26 • C L I N I C A L D E N T I S T RY periodontal diseases and cardiovascular disease and stroke, and a range of other systemic issues. Children with a cleft lip/palate are more vulnerable to tooth decay, so it is important to encourage them to practise good oral hygiene. Children and adults with impairments have the same entitlement to good oral health as the rest of the population but there is evidence that they are at risk from higher levels of oral health need and barriers to care (see Chapter 20). Valuing People’s Oral Health (DH 2007) best practice guidance specifically addresses their oral health needs and makes evidence-based recommendations on how oral health may be improved. Conclusion The dental profession has an important role in helping patients to adopt oral health-promoting behaviour. It is essential that dental professionals understand the need for prevention and provide evidence-based guidance and support. References DH, 2007. Valuing people’s oral health: a good practice guide for improving the oral health of disabled children and adults. DH Publications, London. Kay, E.J., Locker, D., 1996. Is dental health education effective? A systematic review of current evidence. Community Dent. Oral Epidemiol. 24 (4), 231–235. NICE, 2009. Child maltreatment: when to suspect maltreatment in under 16s (Update). NICE clinical guideline 89. <https://www.nice.org.uk/guidance/cg89> [NICE guideline]. Office for National Statistics. Social Survey Division, 2011. Children’s dental health survey, 2003. [data collection]. UK Data Service. SN: 6764, <http://dx.doi.org/ 10.5255/UKDA-SN-6764-1> (accessed 23.03.15.). Public Health England, 2014. Water fluoridation health monitoring report for England 2014. <https://www.gov.uk/government/publications/water -fluoridation-health-monitoring-report-for-england-2014> (accessed 23.03. 15.). Public Health England, 2015. https://www.gov.uk/government/uploads/system/ uploads/attachment_data/file/457102/Ecigarettes_an_evidence_update_A _report_commissioned_by_Public_Health_England_FINAL.pdf>. The Health and Social Care Information Centre, 2011. <http://www.hscic.gov.uk/ pubs/dentalsurveyfullreport09>. The Marmot Review, 2010. <http://www.instituteofhealthequity.org/projects/fair -society-healthy-lives-the-marmot-review>. Social and psychological aspects of dental care The social determinants of oral health 27 Communication and the dental team 29 Changing oral health-related behaviour 31 2 Dental anxiety and phobia 32 Psychological management of pain 35 The social determinants of oral health Oral health has been defined as ‘a complete state of physical, psychological and social well being’. Despite criticism of this definition as setting a standard of health which is unachievable, it does demonstrate that health comprises more than simply the absence of disease and encompasses physical and psychological well-being and the ability to engage in valued social activities (such as work and relationships). Oral health, and oral disease are not evenly distributed across the population, certain groups are more likely to experience oral disease than others, as discussed in Chapter 1. It is possible to characterize those who are most likely to experience caries, periodontal disease and other oral diseases on the basis of social factors (Watt & Sheiham 1999). These inequalities are considered unjust. 1. Social class Despite overall improvements in oral health over the last 50 years, individuals from lower social classes as classified by occupation, those who have lower levels of income, and those with less formal education are all on average more likely to experience dental disease (mainly caries and periodontal disease; Chapter 3) at all ages. 2. Gender Men generally have higher levels of active dental disease than women. Women are more likely to use preventive dental services. 3. Age Edentulousness increases with age. Periodontal disease also shows marked age-related trends. 28 • C L I N I C A L D E N T I S T RY 4. Disability status Individuals with a wide range of physical and mental disabilities have poorer oral health and access services less frequently than individuals without disabilities. 5. Ethnicity The effect of ethnicity on oral health is difficult to differentiate from the effect of social class, since individuals from minority ethnic communities are over-represented in the lower social classes in the United Kingdom. However, there is some evidence to suggest that ethnicity does have an impact on oral health. The dental team can be involved with seven actions that help reduce inequalities (Watt et al 2013): 1. Understanding the oral health needs of the local population. The needs of the population may not match the needs of those patients who attend the practice. Practitioners should consider planning services in the light of the whole population. 2. Focus on early life – the foundations of good health. In line with the strategy for improving the overall population health, it is suggested that particular focus is placed on improving the conditions of children and young people so they have the basis for lifelong oral health (Marmot 2010). 3. Ensuring equity of access and the quality of treatment outcomes. Equity in treatment provision refers to the delivery of services in relation to need, rather than equally. Those with the greatest need require the greatest access. The ‘inverse care law’ suggests that access to dental services has often been greatest amongst those with the least need. By extension if individuals access services they should also be given interventions of proven efficacy. 4. Delivering evidence-based clinical prevention. The guidance Delivering Better Oral Health (DH 2012) provides advice and support for delivering evidence-based clinical prevention, including such interventions as the use of topical fluorides, etc. 5. Team approach. All members of the team should be involved in the endeavour to reduce inequalities. 6. Link to health providers. Oral health should not be seen in isolation. The underlying causes of dental disease, diet, smoking, alcohol use, etc. are common to a range of diseases (Chapter 1). The Common Risk Factor approach suggests that the dental team should be engaged with wider health services to improve all aspects of the health of their patients. 7. Advocacy – supporting action on the determinants of inequalities. Dental healthcare professionals represent a substantial body of opinion, who could act as advocates for policy changes to support oral health. For example, lobbying for changes which Social and psychological aspects of dental care • 29 would reduce sugar consumption – such as taxation, legislation on advertising to children of high sugar foods/drinks, etc. Communication and the dental team Effective communication is central to the practice of dentistry. The benefits include increased patient satisfaction, improvements in adherence to health-related advice, better patient outcomes and a decreased risk of litigation (Newton 1995). Communication refers to a process of transferring information from the Sender to a Recipient via a medium. In a face-to-face consultation, both healthcare professional and patient send and receive information through the medium of interpersonal communication which actually comprises three media (Newton 1995): • • • The verbal medium – the actual words we use; The paralinguistic medium – tone of voice; The non-verbal medium – includes facial expressions, gestures, eye contact, etc. Communication is most effective if all three media are congruent – they all give the same message. It is not enough to say the right words, if your tone of voice and non-verbal communication do not reinforce the importance of your message. Having established the media through which communication takes place, consideration should be given to the structure of the consultation. The Calgary-Cambridge framework provides an overview of the key tasks which a healthcare professional seeks to achieve when communicating with their patients (see Figure 2.1). This consists of a description of the process of the consultation in the middle of the figure, together with two themes running throughout the consultation, shown on either side: Providing Structure and Building the Relationship. Providing structure Be aware of the structure of the consultation and make clear to the patient what is happening. Ensure that the stages progress satisfactorily. Building the relationship A relationship of trust and mutual respect will enable the dental professional and their patient to work towards joint decisions about the most effective pathway of care. Three key skills help to build such relationships: • • Developing rapport through showing an interest in the patient and a willingness to help. Appropriate empathic responses. 30 • • Involving the patient in decision-making through seeking the patient’s opinion of options, and offering the patient choices. C L I N I C A L D E N T I S T RY The consultation The dental consultation has an overall structure similar to nearly all healthcare encounters, but varies in the emphasis given to each phase. The Calgary-Cambridge framework of patient-centred con­ sultation (Figure 2.1) identifies tasks to achieve at each stage of consultation. Initiating the session • Preparation • Establishing initial rapport • Identifying the reason(s) for the consultation Providing structure • Making organisation overt • Attending to flow Gathering information Exploration of the patient’s problem to discover: • Biomedical perspective • Patient’s perspective • Background information (context) Physical examination Explanation and planning • Providing the correct amount and type of information • Aiding accurate recall and understanding • Achieving a shared understanding: Incorporating the patient’s illness framework • Planning: Shared decision making Building the relationship • Using appropriate non-verbal behaviour • Developing rapport • Involving the patient Treatment (when appropriate) • Provision of concurrent explanations. • Ensuring patient is not in distress. • Exploring patient’s concerns/anxieties. • Preventive advice and information Closing the session • Checking patient’s understanding • Ensuring appropriate point of closure • Forward planning Figure 2.1 The Calgary-Cambridge framework for patient-centred consultations (Silverman et al 2004). Reproduced from Silverman, J., Kurtz, S., & Draper, J. (2004). Skills for Communicating with Patients (2nd ed.). Oxford: Radcliffe Publishing Ltd. Social and psychological aspects of dental care • 31 Changing oral health-related behaviour Oral health and the prevention of oral disease (Chapters 1 and 3) are critically dependent upon an individual’s behaviour, notably the following five behaviours: • • • • • A low frequency of sugar-containing foodstuffs, particularly sugar-containing snacks between meals. Regular daily toothbrushing with a fluoride-containing toothpaste. Regular attendance at the dentist or dental professional (at least once every 2 years or more often on the basis of their risk of developing oral disease). Refraining from tobacco use or quitting tobacco use if the individual currently uses tobacco products. Adherence with treatment recommendations such as medica­ tion use. In order to change their behaviour, patients require three things: 1. Specific information about the change required. 2. The creation of an intention to change (that is they need the motivation to change). 3. The creation of an explicit or implicit plan to implement the behaviour change (that is they need volition). Providing information about behaviour change In order to form the basis for behaviour change the information given should be both understandable and memorable (Ley 1992). Improving the understandability of information The information should be presented in a manner which is understandable to the patient: this will include avoiding the use of jargon, technical terms and acronyms, as well as thinking about the sentence structures that are used. Short sentences containing shorter words (those of three syllables or fewer) are more easily understood. Improving the recall of information Recall of health-related information is better when: • • • • The information is given first. The information given is specific (for example ‘Brush your teeth twice a day. Once in the morning, once at night for 2 minutes each time. Use a toothpaste which has fluoride in it’ rather than ‘Brush regularly’. The information is repeated. The importance of the information is emphasized. 32 • C L I N I C A L D E N T I S T RY Creating an intention to change (Motivation) Extensive research has explored the beliefs and attitudes that are related to the intention to change behaviour. The attitudes and beliefs contained in the Theory of Planned Behaviour have consistently been found to predict an individual’s intention to engage in a behaviour (see Figure 2.2), Ajzen (2002) suggests that an individual’s intention to engage in a behaviour is related to their attitudes towards the behaviour (do they believe it will bring benefits, do they believe that they are at risk if they do not change their behaviour, etc.) as well as their belief in the ability to control their behaviour (specifically the behaviour in question – do they think this is something they can change?) and finally a set of beliefs about the norms in their social groups (family, friends, etc.). Where there is support for behaviour change amongst family and friends, then behaviour change is easier. Together these constructs, Attitudes and Beliefs, Social Norms and Control Beliefs create an intention to change. In seeking to engage a patient in the process of behaviour change, explore her/his attitudes towards the behaviour, the views of family and friends, and the individual’s perception of how easy or difficult it will be for them to change. Example questions might include: ‘Do you think that would be a good thing? What benefits might you get from doing this?’; ‘Who do you think could help you with this?’; ‘How difficult from 1 to 10, where 1 is easy and 10 is impossible, would it be for you to do this?’ Creating a plan to implement change (Volition) Intentions often fail to turn into actual behaviour change. There is good evidence that providing patients with techniques to plan the behaviour change can improve the implementation of intentions to change (Gollwitzer & Sheeran 2006). The specific interventions can be simple and can be used in combination: • • • Encourage self-monitoring. Ask the patient to keep a record of the behaviour. Preferably the record should be easy to maintain – for example a printed diary with tick boxes to show when the behaviour was done. Encourage planning when, where and how the behaviour change will occur. When will the patient engage in the behaviour, where, and what will they need to do that. If–then planning. Agree a plan for what to do if the patient forgets. By encouraging the patient to continue when they lapse they are more likely to re-establish the behaviour change. Dental anxiety and phobia Fear of dental treatment and anxiety about procedures are common and can be a major reason why people do not attend the dentist or Social and psychological aspects of dental care Behavioural beliefs Attitude toward the behaviour Normative beliefs Subjective norm Control beliefs Perceived behavioural control Intention • 33 Behaviour Actual behavioural control Figure 2.2 The Theory of Planned Behaviour (Ajzen 2002). Reproduced from Ajzen, I. 2002, ‘Perceived behavioural control, self-efficacy, locus of control, and the theory of planned behaviour’, Journal of Applied Social Psychology, vol. 32, no. 4, pp. 665–682. do not enjoy their visit. Almost all patients have some level of anxiety about their treatment, which may range from very mild to severely phobic. It follows that it is essential to the clinical management of the patient that the dental team assess the patient’s level of anxiety and intervene proportionately (Newton et al 2012). Assessment of dental anxiety The Modified Dental Anxiety Scale (MDAS) is a five item measure of dental anxiety that is reliable and quick to administer. It has cut-offs for mild, moderate, and phobic levels of anxiety. A version is also available for use with children (Modified Child Dental Anxiety Scale, MCDAS). Interventions for individuals with low levels of anxiety Children: • Dental anxiety in very young children may be prevented by avoiding negative experiences and providing positive experiences in the dental surgery. Examples of such approaches could include encouraging a child friendly environment, the provision of acclimatization visits for children where no invasive dental 34 • • • • • • • C L I N I C A L D E N T I S T RY treatment is performed, and in the long term, the use of fluoride supplements to inhibit caries and thus prevent invasive treatment (drillings/extractions). Rapport building. For example researchers used a magic trick to encourage children who on a previous visit to the dental surgery had refused to enter the dental surgery, to sit in the dental chair and have a radiograph. Voice control. There are a number of studies to demonstrate that children respond best to a moderately loud voice with a deep tone. Distraction. Several types of distraction have been reported in the literature, including the use of video-taped cartoons, audio-taped stories and video games. Distraction techniques are most effective if the distracting material is made contingent on co-operative behaviour. Modelling. Allowing children to observe a child or an adult of similar age undergoing treatment successfully and with the minimum of distress is effective in encouraging children to undergo treatment. This technique works best if the child sees the model being rewarded for their co-operative behaviour. Memory reconstruction. Researchers designed an intervention based on an understanding of the processes of human memory which involved using positive images to help children reconstruct their memory of dental treatment. The intervention comprised three components. Firstly, the visual component: pictures taken previously of the child smiling during the dental procedure were shown back to the child as a visual reminder about the dental experience. Secondly, verbalization: the child was asked how he/ she would explain to the parents how well they handled the dental appointment. Thirdly, concrete example: the child was asked to recall a good example of their improved behaviour in the dental setting. Environmental change. Making the dental environment more attractive to children attending the dental surgery can reduce their distress. For example, researchers reported decreased anx­ iety following exposure to positive images of the dental surgery as opposed to neutral images prior to treatment. Adults: • Enhancing the sense of control. Uncertainty is anxiety provoking, and can be reduced by providing preparatory information and by enhancing an individual’s sense of control over the situation. One widely used technique to do this is the ‘stop signal’; the patient is encouraged to raise their hand if they wish the procedure to stop. Social and psychological aspects of dental care • • • • 35 Cognitive distraction, in which the patient is encouraged to think about something other than the dental situation, has been shown to be effective in adults. Evidence suggests that the technique is only useful if the patient is informed that it is likely to reduce anxiety. Environmental change. The smell of lavender in the dental waiting area has been shown to reduce immediate fear about treatment in adults. Encouraging patients to listen to music can reduce anxiety levels in many but rarely in young children. Interventions for individuals with moderate levels of anxiety The adoption of all the approaches identified for individuals with low levels of anxiety will help to create a calm and welcoming environment. In addition, patients with moderate levels of dental anxiety may benefit from the provision of preparatory information. Information on three aspects of the treatment are important: • • • Information about what will happen (procedural information). Information about what sensations the individual will experience (sensory information). Information about what the individual can do to cope with the situation (coping information). Interventions for individuals with high levels of anxiety Where an individual has been identified as having a phobic level of dental fear, specialist care is required. This will combine both pharmacological management (sedation or general anaesthetic; Chapter 9) with specialist psychological therapies such as Cognitive Behaviour Therapy (CBT) (Newton et al 2012). A referral for specialist care should include information on: • • • The level of dental fear, including any specific phobias (such as fear of injections) Any dental treatment need that has been identified Any relevant medical and social history. Psychological management of pain According to the gate control theory of pain, pain is neither solely physical or psychological, but instead a combination of the two. It follows that the psychological and pharmacological management of pain should work together. There are certain psychological approaches that can help patients cope with both chronic and acute pain. 36 • C L I N I C A L D E N T I S T RY Acute pain Reducing anxiety Pain and anxiety are closely related. Just as pain or the anticipation of pain contributes to anxiety, anxiety is one of the contributing factors to pain, either through anxiety giving rise to increased cortical activity and thus increasing our sensitivity to pain or through shifts in attention causing the individual to focus on the source of their pain. Therefore a reduction in anxiety should lead to a reduction in pain. As such the methods outlined in the section on Dental Anxiety and Phobia are relevant to preventing and reducing dental pain. In particular, relaxation techniques such as controlled breathing, progressive muscle relaxation or even hypnosis (self- or clinicianled) can be used to reduce anxiety and pain. In terms of gate control theory, the anxiety reduction techniques operate on the effectivemotivational and sensory-discriminative components of pain. Distraction The brain can only analyse a certain amount of information at once, therefore there is competition between information from our environment and that from our body. As an example, it has been found that people who live alone or have boring, undemanding jobs report more physical symptoms than those who co-habit or have demanding jobs. The use of distraction seeks to shift an individual’s focus from the body towards an external stimulus, and in turn away from the incoming sensory (pain) information to the environment. Distraction in the dental setting may be achieved by having interesting wall displays, playing music or a radio or film in the clinic, asking patients to perform some kind of mental task (e.g. puzzles, guided imagery) or use of virtual reality technology. Increasing perceptions of control. The use of the ‘stop signal’: researchers found that only 15% of those patients who were told to use stop signals (raising their arm) during dental treatment reported some pain compared to 50% of patients who were not invited to use stop signals. There was no difference between the groups in terms of the number of times the patient asked the clinician to stop. Language There is some evidence to suggest that the language used in the dental setting can have an impact on the perception of pain. Using terms that are less likely to activate the cognitive-evaluative or affective-motivational components of pain (e.g. ‘discomfort’ rather than ‘pain’) may result in less pain. Researchers found that 40% of Social and psychological aspects of dental care • 37 children showed behavioural manifestations of pain if the term ‘clean’ was used, compared to 4% if the term ‘tickle’ was used. Chronic pain For individuals with chronic pain, psychological approaches can assist in three ways. Firstly, through encouraging compliance with medication use and other treatments to alleviate the pain (see section on Changing oral health-related behaviour). Secondly, referral to a psychologist for the management of the impact of the pain may be indicated. Psychological approaches to chronic pain include Acceptance and Commitment Therapy (ACT: McCracken & Vowles 2014) – a technique of proven effectiveness which seeks to support individuals to minimize the effect of pain on their everyday life. Rather than seeking to address the pain directly, ACT focuses explicitly on promoting psychological flexibility, through targeting avoidance of distress; promoting acceptance of illness through motivating meaningful activity outside of illness; and addressing the psychological processes that underlie pain-related beliefs. Thirdly, individuals with chronic pain may develop serious psychological conditions such as depression. The dental team can screen for such problems and engage as appropriate with psychiatric and/or psychological services. References and further reading The social determinants of oral health DH, 2012. Delivering better oral health: an evidence-based toolkit for prevention, third ed. Department of Health and British Association for the Study of Community Dentistry, London. Marmot, M., 2010. Fair society, healthy lives: strategic review of health inequalities in England post 2010. Marmot Review, London. Watt, R.G., Sheiham, A., 1999. Inequalities in oral health: a review of the evidence and recommendations for action. Br. Dent. J. 187, 6–12. Watt, R.G., Williams, D.M., Sheham, A., 2013. The role of the dental team in promoting health equity. Br. Dent. J. 216, 11–14. Communication and the dental team Newton, J.T., 1995. Dentist/patient communication: a review. Dent. Update 22, 118–122. Silverman, J., Kurtz, S., Draper, J., 2004. Skills for communicating with patients, second ed. Radcliffe Publishing, Oxford. Changing oral health-related behaviour Ajzen, I., 2002. Perceived behavioural control, self-efficacy, locus of control, and the theory of planned behaviour. J. Appl. Soc. Psychol. 32, 665–682. Gollwitzer, P.M., Sheeran, P., 2006. Implementation intentions and goal achievement: a meta-analysis of effects and processes. Adv. Exp. Soc. Psychol. 38, 69–119. Ley, P., 1992. Communicating with patients. Chapman and Hall, London. 38 • C L I N I C A L D E N T I S T RY Dental anxiety and phobia MDAS. see <http://www.st-andrews.ac.uk/dentalanxiety/>. Newton, J.T., Asimakopoulou, K., Daly, B., et al., 2012. The management of dental anxiety: time for a sense of proportion? Br. Dent. J. 213, 271–274. Psychological management of pain McCracken, L.M., Vowles, K.E., 2014. Acceptance and commitment therapy and mindfulness for chronic pain. Am. Psychol. 69, 178–187. Dental disease Health 39 Oral health 40 Teeth: health and disease 41 3 Other dental disease 58 Periodontal health and disease 68 Other infections 68 Health WHO (World Health Organization) definition of health The preceding chapters have already stressed the importance of health and social inequality. ‘Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity’ (http://www.who.int/trade/ glossary/story046/en/). The Definition has not been amended since 1948. However, the WHO definition has been criticized mainly for the absoluteness of the word ‘complete’ in relation to well-being which unintentionally contributes to the medicalization of society. The requirement for complete health ‘would leave most of us unhealthy most of the time.’ Health is a fundamental human right, recognized in the Universal Declaration of Human Rights. It is also vital to a nation’s economic growth and internal stability. Better health outcomes play a crucial role in reducing poverty. Four key values guide efforts to address health issues: • • • • Recognition of the universal right to health Continued application of health ethics to policy, research and service provision Implementation of equity orientated policies and strategies that emphasize solidarity Incorporation of a gender perspective into health policies. Compared to medical ethics, which focuses on individuals, health ethics also encompasses the full range of health determinants and their interconnections, viewed from a societal or systems perspective. Health is determined by both intrinsic forces, such as genetics, behaviour, culture, habits and lifestyles, and extrinsic forces such as 40 • C L I N I C A L D E N T I S T RY preventative, curative and promotional aspects of the health sector, as well as elements outside the health sector including: • • • • Economic factors, such as trade Social factors, such as poverty Environmental factors, such as climate change Technological factors, such as information technology. The solution to many health problems lies in addressing their root causes (health determinants), many of which are outside the direct control of the health sector. This means it is necessary to integrate with other sectors such as agriculture, transport and housing. For example, poor housing, inadequate and unsafe water, poor diet, poor sanitation and pollution all expose people to health risks. Oral health The ultimate goal of dental care is to assist in the lifelong main­ tenance of a dentition that is functional, comfortable, and aesthetic. Oral health, however, extends to the periodontium, mucosae, salivary glands and craniofacial bone and joints. Disease A disease – an abnormal condition that affects the body – is of four main types: • • • • pathogenic disease, deficiency disease, hereditary disease, and physiological disease. Diseases can also be classified as communicable and noncommunicable. Oral health and disease The main indications of a healthy mouth (Figure 3.1) are: • • • • • Teeth that are intact, of normal colour and shape, in normal position, firm, clean and free of debris or staining Gingivae that are pink, not swollen and neither hurt nor bleed when the person brushes or flosses, and no periodontal pocketing (Chapter 17) No oro-dental pain No swellings or mucosal lesions No bad breath (halitosis; malodour). Most dental (odontogenic) disease is acquired and caused by the build-up and activity of micro-organisms (mainly bacteria) on the tooth surface within the dental bacterial plaque – sometimes called D ental disease • 41 Figure 3.1 A healthy adult mouth. TABLE 3.1 The main dental diseases Dental disease Main microorganism responsible Prevention Treatment Caries Streptococcus mutans Lactobacilli Actinomyces Minimize dietary sugar intake Use fluoride toothpastes and mouthwashes Restorative dentistry (fillings) Periodontitis Porphyromonas gingivalis Many other bacteria Improve oral hygiene, minimize or avoid tobacco use or smoking Scaling, polishing, root planing, periodontal care plaque – a ‘biofilm’ – which sticks and grows if not removed mechanically by toothbrushing and flossing. The activity of the microorganisms (mainly bacteria) in plaque is responsible for, or may aggravate, a variety of oral diseases, in particular the most common issues – dental caries (tooth decay) and inflammatory periodontal disease (gingivitis and periodontitis) (Table 3.1; Fig. 3.2). Other oral diseases are discussed elsewhere in the book, notably in Chapters 13–20. Teeth: health and disease The most common disease to affect dental hard tissues is tooth surface loss – particularly dental caries (tooth decay) – the most common oral disease affecting children and young people (CYP) in England, yet it is largely preventable. While children’s oral health has improved over the past 20 years, almost a third of five-year-olds still had tooth decay in 2012 (Chapter 1). 42 • C L I N I C A L D E N T I S T RY Figure 3.2 A diseased adult mouth. (Courtesy of D. Malamos.) Tooth surface loss may be due to: • • • • • • Dental caries Attrition Abrasion Erosion Trauma (injuries) Abfraction. Dental caries Dental caries (tooth decay) is a dynamic process caused by acids from carbohydrate fermentation by oral micro-organisms, involving the exchange of calcium and phosphate ions between tooth structure and saliva (plaque fluid). The four criteria required for caries to arise are: • • • • a tooth surface bacteria fermentable carbohydrates (sugars) time. The factors involved are illustrated in Figure 3.3. Caries is caused by bacteria that act on carbohydrates (mainly sugars) on the tooth surface to produce acids that, given time, remove minerals such as calcium and phosphate (demineralize) from teeth, leading eventually to a carious cavity (Table 3.2). The teeth at highest risk for carious lesions are the permanent first and second molars due to length of time erupted in the oral cavity and their complex surface anatomy to which plaque adheres. Microbiology of dental caries Bacteria collect around and between the teeth and in pits and fissures, as well as next to the gingivae in plaque – a sticky, creamycoloured mass. Caries does not develop in germ-free (gnotobiotic) D ental disease Tooth • 43 Sugar Bacteria Time Figure 3.3 Factors underlying dental caries. TABLE 3.2 Facts about dental caries Cause Plaque bacteria, especially Streptococcus mutans, which acts on sugars to produce lactic acid, which decalcifies (demineralizes) the teeth Plaque This biofilm tends to form in pits and fissures, interproximally at contact areas; and at the cervical margins (sites where caries begins) Main sugars implicated in caries Sucrose, glucose Sugars and sweeteners rarely implicated in caries Fructose, lactose, sorbitol, aspartame Acidity (critical pH) below which enamel decalcification occurs 5.5 Methods of detection Visual examination Bitewing radiographs (see Chapter 8) Fibreoptic transillumination Electronic caries detectors Lasers Dyes Probe (but may cause damage; see above) Preventive measures Consuming fewer sugars in the diet Using fluorides, e.g. fluoridated toothpastes Using Amorphous Calcium Phosphate (ACP) 44 • C L I N I C A L D E N T I S T RY animals, even when fed a cariogenic diet – bacteria are essential to the process. Caries results, however, not from the action of a single bacterial species, but from acid production by a range of organisms – the ‘non-specific plaque hypothesis’. A biofilm has a complex interaction between bacteria and their extracellular products – creating an environment conducive to tooth demineralization and caries. The most important cariogenic organisms include: • • • Mutans streptococci. A group of Gram-positive cocci, which includes Streptococcus mutans and Streptococcus sobrinus which metabolize sugars at low pH (acidogenic) and are important in caries initiation. They are also called viridans streptococci. Lactobacillus species. Gram-positive bacilli which survive at a low pH (aciduric). Isolated in large numbers from carious dentine. Other bacteria, such as Actinomyces, may also play a role. S. mutans adheres in the ‘biofilm’ on the teeth by converting sucrose into an extremely sticky substance called dextran. The bacteria also act by converting the sugars in the diet to acids (especially lactic acid). The acids destroy (decalcify) the enamel and dentine of the teeth (see Figure 3.4). The acids cause the pH to fall and when the tooth surface plaque pH drops below 5.5, tooth demineralization proceeds faster than remineralization (meaning that there is a net loss of tooth surface mineral structure). Because most plaque-retentive areas are between teeth and inside pits and fissures on chewing surfaces where brushing is difficult, over 80% of cavities begin inside pits and fissures. Areas that are easily cleansed with a toothbrush however, such as the facial and lingual surfaces, develop fewer cavities. The initial rapid drop in plaque pH to a pH of about 5.5, is when demineralization starts (‘critical pH’) (Figure 3.5). The more time the pH is low, the more demineralization occurs; thus the worst pattern of sugar exposure is repeated exposures (e.g. sucking mints) whereas the best is none, or all the exposures at once Figure 3.4 Decalcification. D ental disease • 45 Sugar intake pH Net loss of calcium and phosphate ions below critical pH Time (mins) Sugar intake pH Net loss of calcium and phosphate ions below critical pH Time (mins) Plaque pH Critical pH Figure 3.5 Sugar intake/time graph (Stephan curves) . (e.g. eating all the sweets at midday Saturday). Eating sticky sugars (e.g. toffees), repeatedly eating or drinking sugary foods, or sucking sweets for hours, leads to an extended drop in the pH, and considerable damage. Even more damage occurs if the sugars are eaten just before going to sleep, because saliva production falls during sleep, and therefore the natural cleaning of the mouth is reduced. The same applies if there is hyposalivation for any reason (e.g. after irradiation treatment that damages salivary glands). Decalcification produces opaque whitish areas on the tooth, which are painless. The earliest clinical appearance of caries is thus a ‘white spot’ caused by loss of calcium and phosphate ions from the enamel 46 • C L I N I C A L D E N T I S T RY prisms. Initially, loss is greater subsurface and the tooth surface remains intact. Caries: • • • • • • • • • is found mainly in plaque stagnation areas such as: pits and fissures; just under contact points between adjacent teeth; at gingival margin. May become discoloured – known as ‘brown spot lesion’. Is cone shaped with base on surface. Decalcification is reversible to a point if the person changes their diet and reduces intake of more cariogenic carbohydrates. If lesion progresses, surface breaks down and a cavity is formed. When surface breakdown occurs, the damaged tooth requires restoration. The critical pH for dentine demineralization is higher, at around 6.5 (so less acid needed), and as the dentine is softer than enamel, caries spreads more rapidly once it reaches dentine. Caries may then spread to the pulp eventually causing infection, inflammation and pain (pulpitis). Pulp necrosis may follow, and then periapical abscess formation. Consequences if caries is not treated If the carious process is allowed to progress, it destroys the enamel, causing a cavity to form in the tooth. Eventually it reaches the dentine. Once caries reaches the dentine, the carious process speeds up. In addition, the patient may feel pain on stimulation with sweet/ sour or hot/cold. This pain is similar to the pain that occurs when dentine is exposed due to loss of enamel for other reasons such as trauma, erosion or abrasion. The pain subsides within seconds of removing the stimulus. The pain may be poorly ‘localized’, that is, it may be difficult for the patient to say where exactly it is. Often pain is localized only to an approximate area within two to three teeth of the affected tooth. The inflammation causes swelling of the pulp but, since the pulp is confined within the rigid pulp chamber, the pressure builds up. Thus there is severe and persistent pain in the tooth. The swelling also stops the blood flow into the pulp – which then dies. The pain may then subside for a while. However, the dead pulp is infected with bacteria from the mouth (odontogenic infection). The infection can then spread through the tooth root apex into the alveolar bone and cause apical periodontitis. This is painful, especially when the tooth is touched or the patient bites on it. Such a tooth must be roottreated (endodontics) or extracted (exodontics) in a timely fashion. Otherwise a dental abscess, granuloma or cyst (see below) will almost inevitably form eventually. Pain and dental caries Early caries, that is when there is only enamel decay, is painless. When the caries reaches the dentine, the person may get transient D ental disease • 47 pain with sweet, hot or cold stimuli. When the caries approaches the pulp, the person may feel more prolonged pain, which may sometimes be spontaneous. Once caries reaches the pulp it becomes inflamed (pulpitis), causing spontaneous and severe pain (toothache). Diet and dental caries Carbohydrates in a form such as sugars that can be metabolized by oral bacteria are a necessary prerequisite for caries development (Figures 3.3 and 3.4). There is clear and extensive evidence of the correlation between the frequency and amount of sugar consumption and the prevalence and severity of dental caries (Chapter 1): • • • • epidemiological data show a correlation between sugar consumption and caries on a national basis caries prevalence is higher in communities with high sugar intake, e.g. sugar cane and confectionery industry workers caries prevalence increases following introduction of a sugarcontaining diet in isolated communities, e.g. the Inuit, island communities such as Tristan da Cunha caries decreases following restriction of sugar, e.g. wartime diets. Fermentable carbohydrates (sugars) in the diet are mainly found as non-milk sugars (e.g. sucrose, glucose and fructose), and lactose in milk (milk sugar) which is less cariogenic than other sugars. The most cariogenic are the non-milk sugars which include the common table or cane sugar (sucrose), sugar beet, glucose (dextrose) and fruit sugar (fructose) (Table 3.3). Sugars are also added to many foods and drinks, in particular to refined carbohydrates such as starch, and foods such as cakes and biscuits. Sugars may also be added to foods and drinks where one might not expect them – for example breakfast cereals, canned vegetables, sauces and soups – and are found in some medications. TABLE 3.3 Cariogenic sugars Pure sugars Mixtures Dextrose Brown sugar Fructose (except in fresh fruits and vegetables) Golden syrup Glucose Honey Hydrolysed starch Maple syrup Invert sugar Treacle Maltose Sucrose 48 • C L I N I C A L D E N T I S T RY Dietary starch is broken down slowly by salivary enzymes to glucose and maltose, and concentrated fruit juices and dried fruits have a high concentration of sugars such as fructose so all of these products are also cariogenic. Fresh fruits and vegetables are not significantly cariogenic (but some can be erosive). Potentially cariogenic foods and drinks thus include: • Buns, pastries, fruit pies • Cakes and biscuits • Dried fruits • Fresh fruit juices • Fruit in syrup • Honey • Ice cream • Jams, preserves • Sponge and other puddings • Sugar and chocolate confectionery • Sugar-containing alcoholic drinks • Sugared breakfast cereals • Sugared soft drinks • Sugared, milk-based beverages • Syrups and sweet sauces • Table sugar. The least tooth damage is done by: • Avoiding consuming sugars completely • Minimizing non-milk sugar intake • Eating sugar-containing products all at once only and over a short period of time • Not eating sugars as the last thing at night. Factors protective of caries Saliva protects against caries. Abundant saliva production or its stimulation by chewing fibrous foods or gum or rinsing the mouth, will help the low pH to recover and give some protection. In people who produce a good amount of saliva the chances of developing caries is far less than in those who have a dry mouth or hyposalivation. Factors other than saliva that may be protective of caries include fluoride, and: • Cocoa • Coffee • Cranberries • Grapes and some other fruits/vegetables • Tea • Wine • Xylitol. D ental disease • 49 Figure 3.6 Tooth decay – maxillary. Particular patterns of caries Arrested caries. Under favourable conditions, a lesion may become inactive – black or dark brown in colour – and has a hard or leathery consistency. Dentine caries. Occurs when enamel caries extends to amelodentinal junction. Spreads laterally and, as it progresses, is cone shaped with base on amelodentinal junction. As dentine is vital, it can respond by laying down reactionary or secondary dentine at surface of the pulp chamber – depends on the rate of caries progression. Early childhood caries (ECC). Also known as ‘nursing bottle caries’ or dummy caries. Describes extensive caries in primary incisors due to prolonged exposure to sugar-containing drinks in a feeding bottle or cup. Teeth most likely affected are the maxillary anterior teeth (Figure 3.6). It is usually a result of allowing children to fall asleep with sweetened liquids in their bottles or feeding children sweetened liquids multiple times during the day. Enamel caries. Simple surface demineralization that looks like a small white chalky area, which eventually cavitates. Fissure caries. Describes caries occurring in the stagnation area at the base of pits and fissures. Frequently the first site to be attacked. Occult caries. Describes extensive dentine caries in the presence of minimal or no clinically evident enamel breakdown. Most commonly occurs under occlusal surfaces. An increasing problem in older children/teenagers. May be due to increased resistance to enamel breakdown as a result of exposure to fluoride. Radiation caries. Caries in people after irradiation that damages salivary glands causing hyposalivation, predisposing to caries. Rampant caries. Describes gross caries, frequently in deciduous dentitions. ‘Rampant caries’ in adults is advanced or severe decay on multiple surfaces of many teeth seen in individuals with poor oral 50 • C L I N I C A L D E N T I S T RY Figure 3.7 Dry mouth – caries. hygiene, stimulant use (due to drug-induced dry mouth), dry mouth such as after radiotherapy in the head and neck region (Figure 3.7) or Sjögren syndrome (Chapter 13), and/or large sugar intake. ‘Meth mouth’ seen in some drug abusers (Chapter 1) is an example. Recurrent caries. Continuation of caries after placement of restoration. Root caries. Occurs following gingival recession. Varies from light yellow to dark brown in colour. Increasing problem in older patients. Secondary caries. New caries occurring at restoration margins. Both secondary and recurrent caries indicate restoration failure, which accounts for a considerable component of operative dentistry. Prevention of caries Whilst dental caries will not develop in the absence of dental plaque, and plaque removal is essential in maintaining periodontal health, dietary control and use of fluoride are more important in caries prevention than is plaque removal per se. Fluorides and Amorphous Calcium Phosphate (ACP) can remineralize demineralized teeth, and various treatments can be used to restore teeth to proper form, function and aesthetics (Chapters 16–18). Diagnosis of caries Caries initially is simple surface demineralization that looks like a small chalky area (smooth surface caries), which may eventually develop into a cavity. Early, uncavitated caries can be diagnosed by blowing air from the 3-in-1 syringe across the surface or by inspection of tooth surfaces using a good light source. Probing with a dental probe was the traditional method for detecting cavities but is now outmoded since it can cause further tooth damage. See http://www .slideshare.net/drkskumar/caries-diagnosis-10066187. D ental disease • 51 Clinical diagnosis Careful inspection of each tooth surface: • • • • • good light is essential drying the teeth enables easier visualization of white spot and early lesions occult caries or caries at approximal surfaces appears as grey/ black discolouration do not use sharp probe – risk of collapsing incipient lesions probe should only be used to remove plaque/food debris. Caries can be difficult to diagnose by clinical examination alone. Other methods include: Radiographic diagnosis Radiographs (X-rays) are often used for less visible areas of teeth. Bitewing radiographs are a crucial aid to the diagnosis of caries • • • on approximal surfaces occult under occlusal surfaces in restored teeth. Bitewing radiographs are required for all new patients if the approximal surfaces of the teeth cannot be clinically examined. At recall visits, the frequency with which bitewings should be taken depends on the patient age and perceived caries risk. The interval ranges from 6 months for children at high risk to 2-yearly for adults at low risk (Chapter 1). High-risk adults and children should have 6 month bitewings. Fibreoptic transillumination (FOTI) A bright light is conducted along a fibreoptic cable and can be directed interproximally. Approximal caries appears as a dark shadow. Whilst the technique is of benefit in epidemiological investigations, bitewings are superior for diagnosis in individual patients. Lasers Allow detection of caries without ionizing radiation in the interproximal regions. Electronic caries detector Designed for detecting fissure caries – has been researched quite extensively but is not in widespread clinical use. Caries detection dyes For use in cavity preparation. Claimed that dye is taken up by carious dentine to enable easier visualization. Variability in caries diagnosis between individual clinicians reflects the difficulties encountered in caries diagnosis. Consistency 52 • C L I N I C A L D E N T I S T RY G.V. Black L B/L Class I F Class IV F/L B/L F Class II Class III B/L Class V B/L Class VI Figure 3.8 Black’s classification. in diagnosis, however, is crucial and in epidemiological studies considerable effort must be made to train and calibrate the clinicians involved to achieve satisfactory reproducibility. Caries charting Carious cavities are most likely to arise where there is plaque retention ‘in stagnation areas’ and such cavities have been classified by Dr G.V. Black as classes I, II, III, IV, or V (Figure 3.8). Class VI was a later addition (Table 3.4). Caries risk The ability to determine caries susceptibility on either a population or individual patient basis would offer a number of advantages (Chapter 1). Population basis permits targeting of resources, location of clinics, implementation of preventive programmes. Individual basis determines the need for caries control measures, timing of recall appointments, decisions as to suitability for advanced restorations, or suitability for orthodontic treatment. D ental disease • 53 TABLE 3.4 Black’s Classification of caries lesions Cavity class Teeth affected by caries Sites affected by caries I Molars and premolars (posterior teeth) Anterior teeth lingually Occlusal two-thirds, pits and fissures II Molars and premolars (posterior teeth) Involves two or more surfaces Interproximal surfaces III Anterior teeth (incisors and canines) Interproximal surfaces IV Anterior teeth (incisors and canines) Interproximal surfaces, including incisal edges V Anterior or posterior teeth Gingival third of facial or lingual surfaces VI (not described by GV Black himself ) Molars, premolars, and canines Cusp tips Various tests have been devised for determining caries risk, based on: • • • • • counts of salivary mutans streptococci (Dentocult SM) or lactobacilli (Dentocult LB) tests of salivary buffering capacity (Dentobuff) tests based on socioeconomic factors existing caries status clinical judgement of dental clinician. Of the above tests, the clinical judgement of the dentist and current caries experience have proved to be the most reliable indicators of future caries. Determination of disease risk is an important factor in determining how frequently patients should attend for dental care (Chapter 1). Assessing caries prevalence and treatment needs in populations The decayed, missing and filled teeth index (DMFT index, see Box 3.1) is the most widely used method of recording caries experience. The ‘DMF’ (decay/missing/filled) index is one of the most common methods for assessing caries prevalence as well as dental treatment needs among populations. The Adult Dental Survey in 2009 showed that in England, Wales and Northern Ireland about one-third of adults had obvious caries, approximately the same as that worldwide (http://www.hscic.gov.uk/pubs/dentalsurveyfullreport09). 54 • C L I N I C A L D E N T I S T RY Box 3.1 DMFT index D = decayed M = missing F = filled T = teeth DMFT applies to permanent teeth DMFS applies to permanent tooth surfaces dmft/dmfs applies to primary dentition Components of DMF can be used to determine: D = Index of treatment need DMF F = Index of restorative provision (also known as Care index) DMF M = Index of treatment failure DMF Caries is most prevalent in Latin American countries, countries in the Middle East and South Asia, and least prevalent in China. Caries has decreased in many developed countries, a decline usually attributed to preventative measures – particularly fluoride (Chapter 1). Nonetheless, countries that have an overall decrease in caries continue to have a disparity in the distribution, with a higher prevalence in resource-poor groups. Attrition Attrition is a form of tooth surface loss. It is the wearing away of a tooth’s biting (occlusal) surfaces due to chewing (mastication). It is most obvious in people using a coarse diet and/or with a habit such as bruxism (tooth grinding). The incisal edges of the anterior teeth and the premolars and molars cusps wear down. Once the enamel is breached, the softer dentine is lost faster than the enamel, which results in a flat or hollowed surface (Figure 3.9). The tooth may need a restoration (see Chapters 16–19). Abrasion Abrasion is another form of tooth surface loss – the wearing away of the hard tissues at the neck of the tooth by a habit such as toothbrushing with a hard brush and coarse toothpaste. The gingiva recedes but is otherwise healthy. The cementum and dentine wear down but the harder enamel survives, resulting in a notch (Figure 3.10). The exposure of dentine also means the tooth may become sensitive to hot and cold (“hypersensitivity”). There may also eventually D ental disease • 55 Figure 3.9 Attrition. Figure 3.10 Abrasion. be tooth fracture. The tooth may need a restoration (see Chapters 16–19). Use of desensitizing toothpastes and fluoride applications may also help. Erosion Erosion is tooth surface loss caused by dissolution of the tooth minerals by acids (pH of 5.5 or lower) other than those produced in caries. In most patients there is little more than a loss of normal enamel contour (Figure 3.11) but, in more severe cases, dentine or pulp may also become involved. Causes of erosion include: • • • • Fruits or fruit drinks (citrus fruits such as grapefruit, lemon, lime or orange), cola (and other carbonated drinks) Wines and other alcoholic drinks Vinegar (often used on salads and ‘fish and chips’) Regurgitation of stomach (gastric) acid (pH is ~2), e.g. in bulimia and stomach difficulties as well as recurrent vomiting such as in anorexia or alcoholism. Patients who have a habit that causes erosion should be counselled to stop the habit. The teeth may need to be restored or protected. 56 • C L I N I C A L D E N T I S T RY Figure 3.11 Erosion from chewing ascorbic acid. Trauma Trauma to the teeth is commonly seen in sports, road accidents, violence, seizures and in bad restorative dentistry! Tooth trauma is seen mainly in boys or young men. It usually affects the maxillary incisors. Because of the impact of trauma, a tooth can be lost from the mouth or dislodged within its socket, fractured (the crown or root), or it can die (see Chapter 16). Dental trauma is also seen in children who have been abused. In all forms of trauma, there can also be damage to the jaws or soft tissues. Thus it is important for the clinician to take a careful history and do a thorough examination to ensure there are no injuries elsewhere in the body, especially head or chest injuries (which can be fatal), or damage to the neck – which can lead to paralysis or death. Abfraction This is a notched-out area on the tooth root at the gumline which can be caused by toothbrush wear but since studies show that notching slowly increases over time even with corrected tooth brushing habits, it has been suggested that teeth flex very slightly under improper forces in grinding and clenching and deepen the notched areas. Consequences of tooth surface loss Tooth loss can cause hypersensitivity and/or a cosmetic issue and a minimum of 20 teeth is required to enable satisfactory mastication. Other sequelae can be: Periapical abscess (Dental abscess) A dental abscess often follows pulpitis – usually caused by caries or trauma. The pulp, and so the affected tooth, is dead (non-vital). Therefore, although the tooth cannot itself cause pain, the inflammation travels to the bone surrounding the tooth apex. This is called D ental disease • 57 Figure 3.12 Periapical abscess discharging buccally. Figure 3.13 Periapical (dental) abscess arising from a lower molar tooth, with resultant facial swelling. Abscess left mandible. apical periodontitis. If the inflammation persists, it may cause an abscess (called an apical, periapical or dental abscess), which produces pain and may also result in a swelling, typically in the labial or buccal gingiva (Figure 3.12). Pain may abate if the abscess discharges. Sometimes the face can swell (Figure 3.13) and the patient may also develop cervical lymph node swelling and a fever. Extraction or root canal treatment of the affected tooth will be required to remove the source of infection, or the problem will return. Analgesics and antibiotics may be needed in the short term to alleviate the patient’s symptoms. If the odontogenic infection spreads, for example to the neck, then this is an emergency and hospital care is needed as there is a danger the airway could be obstructed and the patient could die (Chapter 14). If the tooth is not correctly treated, a cyst (periapical, radicular or dental cyst) can develop. Again, either root canal treatment or root 58 • C L I N I C A L D E N T I S T RY end surgery (apicoectomy or apicectomy) will then be needed (see Chapter 19). Infections of dental origin (odontogenic infections) Infections that are dental in origin frequently have a mixed bacterial aetiology, e.g. streptococci (aerobic and anaerobic) and Bacteroides (anaerobic). The majority of dental infections which remain localized include: Apical (dental) abscess. The most common type of abscess arises from an infected pulp chamber. Periodontal abscess. An infection within a periodontal pocket (Chapter 17). Pericoronitis. Infection under the operculum (i.e. the mucosa that covers a partially erupted tooth). Primary treatment is by irrigation under the operculum with aqueous chlorhexidine solution (0.2%). It may be necessary to remove the maxillary third molar to reduce occlusal trauma. Systemic antibiotics should be considered if there is evidence of trismus, lymphadenopathy, or spreading infection. Spreading infection. Whilst most infections remain localized, an infection may spread. Pus from an infected tooth will spread along the path of least resistance. This may present as an extra- or intraoral sinus, but can on occasion spread along tissue and fascial planes to produce severe, life-threatening systemic infections. The pattern of spread associated with specific teeth often follows a distinct path. In all these spreading infections be alert to systemic conditions possibly underlying the acute spread, e.g. diabetes, immune deficiency. Other dental disease (see also Box 3.2) Tooth eruption problems Just before primary teeth erupt, the gingiva may show a bluish colour and become swollen. This is usually because of transient bleeding into the gingiva, which stops spontaneously. An infant who is teething may show irritability, disturbed sleep, flushed face, drooling, a small rise in temperature and/or a rash. Teething does not cause diarrhoea or any other disease (but these may occur coincidentally). D ental disease • 59 Box 3.2 Quick revision aid of the main oral signs and symptoms Bleeding: Haemangioma (a tumour of the cells that line the blood vessels) Trauma Bleeding tendency Inflammation Blisters: Skin diseases Infections Burns Allergies Cysts Mucoceles Discoloured teeth: Extrinsic discolourations (brown or black): – Poor oral hygiene – Smoking – Beverages/food (e.g. tea, coffee, red wine) – Drugs – Betel Intrinsic discolourations: – Localized: trauma; caries; restorative (filling) materials – Generalized: tetracyclines; excessive fluoride; genetic diseases Dry mouth (xerostomia): Drugs Dehydration Psychogenic cause Salivary gland disease Early tooth loss: Trauma Dental caries Periodontal breakdown Tumours Facial swelling: Inflammation (e.g. infections or bites) Trauma Allergies Cysts Neoplasms Halitosis: Volatile foodstuffs Drugs and tobacco Oral disease Systemic disease: – Respiratory disease – Metabolic disease Psychogenic cause Late tooth eruption: Impacted teeth Cancer treatment • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • (Continued) 60 • C L I N I C A L D E N T I S T RY Box 3.2 Quick revision aid of the main oral signs and symptoms—cont’d Pain: Dental disease Migraine and similar vascular disorders Trigeminal neuralgia Psychogenic pain Temporomandibular pain dysfunction Referred pain (e.g. angina) Pigmentation: Racial Food/drugs Tobacco Betel Chlorhexidine Minocycline treatment Endocrinological (Addison disease) Red areas Congenital conditions: – Haemangiomas Trauma Inflammatory Neoplastic and possibly pre-neoplastic Salivary swelling: Inflammatory Obstruction Neoplasm Soreness and ulceration: Systemic disease Malignant disease Local causes Aphthae (recurrent aphthous stomatitis) Drugs Swellings and lumps: Congenital Allergic reactions Inflammatory lesions Neoplasms Traumatic Trismus: Infection and inflammation near masticatory muscles Temporomandibular joint-dysfunction syndrome (facial arthromyalgia) Fractured or dislocated jaw Arthritis After radiotherapy White lesions: Congenital conditions Cheek biting Inflammatory: – Infective (e.g. candidosis) – Non-infective (e.g. lichen planus) Neoplastic and possibly pre-neoplastic: – Keratoses (leukoplakias) – Carcinoma • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • D ental disease • 61 Delays in eruption Teeth can erupt up to 12 months late – this is usually of little significance. Longer delays in tooth eruption are often caused by local factors such as the tooth becoming impacted against another tooth as it travels through the bone. The teeth that most often get impacted are the third molars (wisdom teeth), premolars and canines, because these are usually the last teeth to erupt. If tooth eruption is delayed for more than one year the dentist will often take a radiograph to check the reason. Impacted teeth Teeth can fail to erupt fully because of insufficient space in the dental arch. The teeth most commonly affected are the third molars (wisdom teeth, lower third molars most commonly), second premolars and canines (Figure 13.14). Impacted teeth may well be asymptomatic, but occasionally they can cause pain. This is usually because of the caries or pericoronitis that develops. Impacted teeth may also lead to cyst formation. There is no evidence that they contribute to malocclusion. Treatment may include orthodontics to guide the impacted tooth to its correct position and sometimes surgery. The latest guidelines of the National Institute for Health and Care Excellence (NICE) recommend removal of impacted teeth only if they are causing problems such as recurrent pericoronitis or caries but these guidelines have been challenged and are under consideration. Malocclusion. When the teeth in the upper and lower arches do not ‘bite’ normally, for example because they are very crowded or some teeth are missing. Pericoronitis. The inflammation of the gingival flap (operculum) over an erupting or impacted tooth. Usually this happens around the lower third molar (see Chapter 14; Figure 3.14). Figure 3.14 Radiograph of impacted third molar. 62 • C L I N I C A L D E N T I S T RY Variations in tooth number Hypodontia (too few teeth) Reasons for teeth missing from the dental arch include: • • • The tooth may have failed to erupt It may not have developed It may have been lost prematurely. Teeth can be lost due to extraction, an injury, such as while playing sports, or if a person is assaulted or has a fall, or is involved in a road traffic or other accident. This is more common in younger males. Teeth can also be lost due to the extraction that is required if caries has destroyed the tooth to the point that it cannot be restored. People with periodontal disease can lose teeth because of the loss of attachment. Hypodontia if genetic is not uncommon. It most often affects the third molars, the second premolars and the maxillary lateral incisors. Occasionally hypodontia can occur as part of a generalized (systemic) disorder such as ectodermal dysplasia. Rarely, all the teeth are absent (anodontia). In hypodontia, when the permanent successor is missing, it is common for the deciduous tooth to be retained long after it should have been shed (primary teeth <1%, permanent teeth 6%). Where the primary teeth are affected, one-third to one-half of permanent teeth are affected. In addition, teeth present may be smaller than average. Orthodontic assessment is recommended when planning restorative care. The patient may need a restoration (see Chapter 19). Tooth replacement can be with one of the many kinds of fixed or removable prostheses (dentures, bridges), or by dental implants. Missing upper lateral incisors can be unilateral or bilateral. If one side is missing, the other side is often small and conical. This has an effect on the eruption of the permanent canine – there is a greater chance of it being displaced palatally. Treatment options include: • • • • accept restorative alone space closure space localize and restorative treatment. Missing premolars. Most commonly affects the second premolar. Must decide on retention/extraction of the second primary molar – influenced by arch crowding and tooth condition. Remember, a retained primary molar may infra-occlude. Missing lower central incisor. If crowded, reasonable space closure may result following extraction of the primary tooth. If uncrowded, D ental disease • 63 may wish to retain the primary tooth as an interim measure and then, when lost, consider adhesive bridgework. May require orthodontic alignment prior to this. Hyperdontia (too many teeth) In the mixed dentition period it is not uncommon to see what appear to be two rows of teeth in the lower incisor region. Additional teeth may be seen occasionally in otherwise healthy individuals, occasionally in those with rare disorders. • • • • Extra teeth of normal shape (supplemental teeth) are uncommon, but most frequently seen in the maxillary lateral incisor, and in the premolar and third molar regions of either jaw. Extra teeth of abnormal form (supernumerary teeth) are also uncommon, usually small and/or conical in shape and are seen particularly in the midline of the upper arch (mesiodens). Supplemental teeth (duplication of teeth). Permanent upper lateral incisor is the most commonly involved. Usually extract one. Supernumerary teeth. Primary teeth 0.2–0.8%, permanent teeth 1–3%, are more common in males and the maxilla. Most common in upper incisor region. May be: • Conical. Usually in midline; either displaces the central incisor or prevents eruption. Also found high and inverted in the palate. • Tuberculate. Often paired; most commonly on the palatal side of central incisors and prevent eruption. Orthodontic assessment is recommended. Must establish the tooth position with appropriate radiographic technique. Can leave if not causing any problems. Do not remove before age 6 years. If intervention is essential, space requirements must be considered – often need to extract the primary canines. Delayed incisors may take some time to erupt and may require surgical exposure. Anomalies of tooth form, position or structure Although the delicate process of tooth development is generally well protected in the developing baby or child, it may be affected by diseases, radiotherapy, drugs or infections. Abnormalities of tooth form Dens-in-dente. Must check for this (radiographically) if the lateral incisors are small and conical. Often requires extraction. Dilaceration. Abnormal angulation between the crown and root or within the root. May be related to intrusive trauma to primary dentition. May fail to erupt. 64 • C L I N I C A L D E N T I S T RY Abnormalities of tooth position Impacted first molars. Impact behind second primary molar due to crowding or abnormality in tooth eruption such as orientation of the crypt. Treatment possibilities include keeping under observation but must maintain good oral hygiene. May self-correct if mild. Alternatively, attempt disimpaction using a separator or extract the second primary molar; this will, however, result in space loss. Abnormal position of crypts. The crypt of any tooth can be displaced or rotated. Lower second premolar is most commonly affected. Little can be done at an early age. Ectopic upper canines. Incidence 1–2%; 90% lie palatally or in line of arch. Early recognition is very important. By age 9 years should be palpable as a bulge high in the buccal sulcus. If not apparent by age 10 then carry out a clinical examination and appropriate radiographs. The prognosis is markedly improved if detected early. Extraction of the primary canine may help to encourage eruption in the correct position. Other options: • • • • accept and review extract surgically expose and align orthodontically transplant. Transposition. In the upper arch this usually involves canine and first premolar. In the lower arch it is usually the canine and lateral incisor. Difficult to correct once established. If detected early in the lower arch attempts to align the lateral to the central incisor can be instituted before the canine erupts. Abnormalities of tooth structure Result from disturbances during the period of tooth formation. Abnormal enamel Enamel hypoplasia. Between birth and 6 years of age, the permanent incisors and canines are developing (see Chapter 15). If the developing tooth bud is damaged, it can produce a cosmetic problem, because the damage will be evident on smiling. Enamel hypoplasia is when the tooth crown appears opaque, or yellow-brown or deformed. Infections such as German measles (rubella), cancer treatments or jaundice may cause this type of hypoplasia. The defects correspond to the site of tooth enamel formation at the time of the insult (‘chronological’ hypoplasia). Enamel is reduced in thickness or of deficient structure. Presentation ranges from pits and grooves to gross abnormalities. Enamel hypomineralization. Enamel is of normal structure but not fully mineralized. Presents as changes in colour and translucency. D ental disease • 65 Local aetiology. Infection, trauma, irradiation, idiopathic. Usually affects only one or two teeth. General aetiology. Environmental results from systemic disturbance during period of tooth formation. May occur pre-, peri-, or post­ natally, e.g. rubella, syphilis, childhood infections, excess exposure to fluoride. The term molar–incisor hypoplasia (MIH) has been used for defects of first permanent molars and incisors. Hereditary. e.g. amelogenesis imperfecta or ectodermal dysplasia. Affects several or all teeth. Amelogenesis imperfecta. There are two common variants: • • Hypomineralized type. Matrix formation normal, calcification is abnormal. Mainly autosomal dominant. Hypoplastic type. Matrix formation abnormal, but any tooth (enamel) matrix formed is normally calcified. Mainly X-linked. Abnormal dentine Dentinogenesis imperfecta. Dentine consists of a reduced number of wide irregular tubules, with areas of atubular dentine. Loss of scalloping at ADJ. Teeth have opalescent bluish appearance. Teeth wear rapidly as enamel is lost. Discoloured teeth Discolouration of several teeth is usually because of superficial (extrinsic) staining that results from: • • • • • Poor oral hygiene Use of substances such as tobacco, betel nuts, khat, tea, coffee, red wine, coloured foods or chlorhexidine Caries Trauma Tooth filling material. Such superficial tooth discolouration affects mainly the interproximal and cervical surfaces of the teeth (where plaque also accumulates) and can be removed by the dental clinician. Generalized ‘intrinsic’ tooth staining of a brown or grey colour is caused by the use of the drugs called tetracyclines by a pregnant or lactating mother or children under the age of 8 years. Tetracyclines can cross the placenta and then enter breast milk and are taken up by developing teeth and by bone. Intrinsic staining cannot be removed by the dental clinician. However, because of this problem, tetracyclines are no longer recommended for pregnant women and infants. Staining may also be because of hypoplasia or some rare inherited tooth defect (amelogenesis imperfecta or dentinogenesis imperfecta). 66 • C L I N I C A L D E N T I S T RY Discolouration of a single tooth is usually intrinsic, that is from within the tooth, and happens because the tooth is: • • • Non-vital Heavily filled or Carious. Non-vital teeth progressively darken more with time, sometimes to a brownish colour, and also become more brittle. Tooth cleansing, whitening and restorative options such as veneers or crowns may be used to improve or correct cosmetic defects. Fluorosis Fluoride in the correct amount usually protects the tooth against caries by hardening the enamel, which is why patients are encouraged to use fluoridated toothpaste/mouthwash and drink fluoridated water. However, excessive intake of fluoride can cause fluorosis, which also causes discolouration of the teeth. Depending on the amount of fluoride, defects can range from white flecks or spotting or diffuse cloudiness to yellow-brown or darker patches and staining and ‘pitting’ of the enamel (see Chapter 1). High levels of fluoride in drinking water are uncommon in the developed world, but are common in parts of the Middle East, India and Africa. Swallowing large amounts of fluoride toothpastes or mouthwashes, or overdose of fluoride supplements can also cause fluorosis. Teeth with severe fluorosis can be restored with veneers or crowns. Tooth (dentine) hypersensitivity Tooth hypersensitivity is often the result of abrasion from overenthusiastic toothbrushing (see above). Exposure of the dentine to cold air, water or fruit drinks can cause pain. Use of a good toothbrush with an effective method of tooth cleaning minimizes the risk of tooth hypersensitivity. Carious teeth can also be hypersensitive. Whitening often causes or increases hypersensitivity. If a person has tooth hypersensitivity they should see a dental clinician to ensure there are no cavities and whether they require any treatment. Abnormal cementum Hypercementosis. May be associated with inflammation, over-/ underloading, Paget’s disease. Hypocementosis. Associated with hypophosphatasia. Malocclusion See Chapter 15. D ental disease • 67 Pain Pain in the orofacial region is common. Mostly there are obvious local causes for the pain, relating to the teeth (odontogenic pain) (Table 3.5). Occasionally, pain is: • • • • Neuralgia (nerve pain) Migraine More imagined than real, especially in patients with psychological problems Referred to the mouth from elsewhere such as the heart (angina). Pain can vary in: • • • Nature (e.g. throbbing, burning, dull, stabbing) Frequency of occurrence Severity or intensity. The diagnosis is usually made from the history and the pain features. For example, odontogenic pain may be throbbing with an obvious location, the pain of trigeminal neuralgia (see below) is lancinating (stabbing) and unilateral, and idiopathic facial pain tends to be dull and may be bilateral. A thorough examination and radiological tests are important in order not to miss detecting organic disease, and thus avoid mislabelling the patient as having psychogenic pain. TABLE 3.5 Local causes of oral pain Source of pain Character Exacerbating factors Associated with Pain provoked by Dentine Evoked by a stimulus, does not last long Hot/cold, sweet or sour Caries, defective restorations, exposed dentine Hot/cold, sweet, probing Pulp Severe, intermittent, throbbing Hot/cold, sometimes biting Pulpitis Hot/cold, probing Periapical area For hours at same intensity; deep, boring Biting Periapical abscess Percussion, palpation (touch) Gingiva Pressing, annoying Food impaction, toothbrushing Acute gingivitis Palpation Mucosa Burning, sharp Sour, sharp food Erosions or ulcers Palpation 68 • C L I N I C A L D E N T I S T RY Halitosis Halitosis or oral malodour is common on awakening (morning breath). It can be readily rectified by eating, brushing the teeth and rinsing the mouth with fresh water. Malodour at other times may be due to eating certain foods such as garlic, onion, spices, cabbage, cauliflower or radish. Durian is a fruit with a particular malodour. Habits such as smoking or drinking alcohol also cause malodour. Individuals who have poor oral hygiene soon develop halitosis, but it is made worse by any form of oral infection, such as: • • • • • • • Gingivitis Periodontitis Dental abscess Dry (infected) extraction socket Sinusitis Tonsillitis Ulceration. Rarer causes of halitosis include more general conditions such as: • • • • • • • • • Respiratory disease Sinusitis Nasal infections Lung problems Metabolic disease Diabetes Kidney disease Liver disease Psychiatric disease (where halitosis may be imagined). Treatment includes improving oral hygiene and reducing the tongue coating by gentle and regular tongue cleaning. Mouthwashes containing chlorhexidine gluconate, triclosan or cetylpyridinium (essential oils), may help. Toothpastes containing triclosan and a copolymer (e.g. Colgate Total toothpaste) could also be used. Periodontal health and disease In its widest sense, periodontal disease includes all pathological conditions of the periodontium but predominantly refers to inflammatory diseases that are plaque-induced, i.e. gingivitis and periodontitis. These are discussed in Chapter 17. Other infections Dry socket (focal alveolar osteitis) (see Chapter 14) D ental disease • 69 Sinusitis General aspects Infection of the paranasal air sinuses (maxillary most commonly, but also ethmoid, sphenoid and frontal) is usually bacterial. It may be preceded by viral, or other factors. Clinical features Headache on wakening is typical, with pain worse on tilting the head or lying down, and nasal obstruction with mucopurulent nasal discharge. General management Diagnosis is from the history, plus tenderness over the sinus, dullness on transillumination, and radio-opacity or a fluid level on plain X-rays of the sinuses (sinus opacity may be due to mucosal thickening rather than infection, but a fluid level is highly suggestive of infection). Antral opacities in children can be difficult to evaluate since they are seen in up to 50% of healthy children under age 6 years. Computed tomography (CT) is now the standard of care. Ultrasonography may be helpful. However, the gold standard for diagnosis remains sinus puncture and aspiration. Sinusitis is classified as acute, chronic or recurrent. In acute sinusitis, the bacteria most commonly incriminated are Streptococcus pneumoniae and Haemophilus influenzae. It resolves spontaneously in about 50%, but analgesics are often indicated and antibiotics may be required if symptoms persist or there is a purulent discharge. Treatment is drainage using vasoconstrictor nasal drops, such as ephedrine or xylometazoline. Inhalations of warm, moist air, with benzoin, menthol or eucalyptus, may give symptomatic relief. In adults, >7-day course of antimicrobials is indicated: using amoxicillin or ampicillin or co-amoxiclav (erythromycin or azithromycin, if penicillin-allergic), or a tetracycline, such as doxycycline, or clarithromycin. In children, high dose amoxicillin, cefuroxime or co-amoxiclav are recommended especially if the child has received antibiotics within 4 to 6 weeks prior to the infection. Chronic sinusitis involves anaerobes, especially Porphyromonas (Bacteroides), and half are beta-lactamase producers. It may follow acute sinusitis, especially where there are local abnormalities, allergic rhinitis, or impaired defence mechanisms such as cystic fibrosis or HIV disease. Gram-positive cocci and bacilli as well as Gramnegative bacilli may also be found – especially in HIV/AIDS patients and those on prolonged endotracheal intubation. Pseudomonas aeruginosa (up to 5% of cases are caused by Pseudomonas, especially in cystic fibrosis), Acinetobacter baumannii and Enterobacteriaceae are 70 • C L I N I C A L D E N T I S T RY also implicated. In immunocompromised persons, or fungi may also be involved, including Mucor, Aspergillus or other species. Chronic sinusitis responds better to drainage by functional endoscopic surgical techniques, plus antimicrobials – such as metronidazole with amoxicillin, erythromycin, clarithromycin or a cephalosporin. Recurrent sinusitis should be treated with drainage, plus antimi­ crobials, and investigation to determine whether there is any underlying cause. Dental aspects Dental treatment should be deferred until after recovery. GA should be avoided since there is often some respiratory obstruction and infection can spread to the lungs. Inhalational sedation may be impeded if the nasal airway is obstructed. Mycoses may infect the sinuses in immunocompromised persons. References Universal Declaration of Human Rights. <https://en.wikipedia.org/wiki/Universal _Declaration_of_Human_Rights>. WHO, 1948. WHO definition of health. (Official Records of the World Health Organization, no. 2, p. 100). <https://en.wikipedia.org/wiki/Universal_Declaration _of_Human_Rights>. The dental team Introduction 71 Regulation of dentistry 72 Dental undergraduate education and training 72 4 Dental postgraduate education and training 78 Specialist dentists 79 The dental team 79 Introduction Dentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, commonly in the dentition but also the oral mucosa, and of adjacent and related structures and tissues, particularly in the maxillofacial area. Dentistry is widely considered important for overall health. Dentistry originated in barbery (from Latin barba, ‘beard’) – people whose occupation was mainly to cut, dress, groom, style and shave hair. In the 1800s dentists, barbers, and surgeons separated as professions. Modern dentistry is all about teamwork and involves a clinician, often the dentist, together with a group of Dental Care Professionals (DCPs) which may include the: • • • • • • dental nurse dental technician dental therapist dental hygienist orthodontic therapist and clinical dental technician. Dental treatment is carried out by the dental team and in the United Kingdom (UK) primary care dentistry is mostly in NHS, private or mixed/NHS private practices or in institutions (prisons, armed forces bases, etc.). Dental clinicians in secondary care services are usually based in dental or general hospitals employed either by the NHS or by Universities (with honorary [unpaid] status in the NHS). Consultants are specialists who see patients seeking secondary or specialist levels of care but have an ever increasing focus on multidisciplinary treatment provided within different medical or dental teams. The key role of the consultant has been to provide support and advice predominantly for patients referred by dentists within primary care and other secondary provider services and where appropriate, 72 • C L I N I C A L D E N T I S T RY to carry out patient treatment. All consultants have a commitment to education, research and training with honorary consultants committed to education and training of undergraduate and postgraduate dental students including NHS trainees in dentistry, specialities and also dental professionals. Regulation of dentistry All healthcare professionals are subject to regulation overseen by the Professional Standards Authority for Health and Social Care (PSA: previously known as The Council for Healthcare Regulatory Excellence [CHRE]), accountable to Parliament. The PSA oversees the General Dental Council (GDC) – the body that regulates all dental professionals. The regulators’ functions include: • • • • Maintaining the Dentists’ Register and the Dental Care Professionals Register Setting standards of behaviour, education and ethics Dealing with concerns about professionals who may be unfit to practise because of poor health, misconduct or poor performance. Regulators can remove people from their register and therefore prevent them from practising. If a registrant’s fitness to practise is challenged, their GDC registration and the licence to work professionally may be under threat Determine which dental qualifications are recognised as being eligible to entitle the holders to be registered on the General Dental Council’s Register of Dentists; see Table 4.2. The stated aims of the GDC are to: • • • Protect patients • Promote the confidence of the patients and public in all dental professionals • Assure the quality of dental education for all UK dental professionals Ensure dental professionals keep their knowledge up to date Help patients with complaints. The GDC achieves these aims by setting the standards and principles for education (Standards for Education; Standards and Requirements for Providers of Education and Training Programmes, 2012) and for ethical dental practice in the UK (See Standards for the Dental Team, 2013a; Box 4.1). Dental undergraduate education and training All dentists in the UK initially follow the same education and training, in order to qualify to work as a dentist. A candidate initially needs to obtain a bachelor’s degree (either a BDS or BChD) from one of the approved dental schools. This is then followed by further training related to the specialty chosen. T h e dental tea m • 73 Box 4.1 GDC: Standards for the dental team (2013a) Keypoint The GDC Registers for Dental Professionals in the UK The GDC maintains ‘registers’ for dentists and dental care professionals: Dentists – the Dentists Register Dental care professionals – the Dental Care Professionals Register. The registers include the names of all the dentists and dental care professionals who are registered to practise in the UK, regardless of whether they work in the National Health Service (NHS), private practice or any other form of practice. Those who are registered are called registrants. All dental professionals must be either registered with the GDC with their registration recorded on the Dental Care Professionals Register, undergoing a recognized course leading to registration or booked to commence such a course at the earliest opportunity. Dental professionals without a recognized UK qualification may be eligible to have their qualification and/or experience assessed. If the assessment is successful, their name will be entered onto the DCPs Register. Assessment is available for the following: Those with a formal qualification from an EEA member state. Those with a formal qualification from overseas. • • • • Standard dental courses last five years and include academic education combined with theoretical and practical training in all aspects of dental practice. Subjects studied include a wide range of health, biological and behavioural sciences, as well as clinical skills in all dental disciplines. The academic requirements for entrance to dental school are high. They vary according to the school and so should be checked individually. Accelerated dental courses last four years and include academic education combined with theoretical and practical training in all aspects of dental practice. These are for graduates who hold a 2 : 1 (or better) degree with a large element of biology and chemistry which gives them exemption from the first year of a five-year dental course. Pre- BDS/BCHD courses are available for candidates with non-science subjects to offer at A level (or equivalent). The pre-dental year is a preliminary course in chemistry, physics and biology and normally lasts 30 weeks and would immediately precede the five-year degree course. See https:// w w w.healthcareers.nhs.uk/explore -roles/dental-team/dentist/ entry-requirements-and-training-dentistry. The Dental Schools Council The Dental Schools Council represents the interests and ambitions of UK Dental Schools as they relate to the generation of national health, wealth and knowledge acquisition through research and the profession of dentistry. 74 • C L I N I C A L D E N T I S T RY As the authoritative voice of all UK Dental Schools, the Dental Schools Council aims to: • • • • • • • Be a principal source for informed opinion and advice on all matters concerning dental education and research in dental schools in the United Kingdom, on relations between dental schools, medical schools, the National Health Service and other clinical care providers, and on relations with university dental schools and faculties in other countries. Work to improve and maintain quality in basic dental education, clinical dental training and dental research, and to facilitate sharing of experience Be the principal source for informed opinion and advice on all matters concerning the roles and functions of staff and honorary staff of dental schools Promote dental education and research through collaboration with Universities UK, the Higher Education Funding Bodies, the National Health Service, Government Departments, the General Dental Council, the Medical Royal Colleges, the Research Councils, Dental Research Charities, the Association of Medical Research Charities, the Medical Schools Council, the Association of UK University Hospitals, the British Dental Associations and other organizations Serve as a point of reference for the media Promote equal opportunities in all aspects of dental education, research and training Consider such other matters as the Dental Schools Council shall direct. <http://www.dentalschoolscouncil.ac.uk/> The role of the General Dental Council (GDC) The primary role of the GDC is to maintain the Dentists’ and Dental Care Professionals’ Registers and to protect patients. The GDC’s role in relation to education and training is to ensure that those who join the registers are fit to practise at the point of registration and remain so throughout their working lives. Its responsibility includes defining the outcomes required, and to make sure these are met through education, training and assessment processes to ensure that at first registration registrants are ‘safe beginners.’ The stated guiding principles for the GDC’s role in relation to education and training include safety and quality of care for patients in addition to ensuring current and future oral health needs. In defining the outcomes required for registration, the GDC takes into account equality and diversity requirements; the knowledge, skills, attitudes and behaviours that a student or trainee must T h e dental tea m • 75 demonstrate as having attained to be appropriate for registration, including professionalism, communication, clinical ability and technical ability, as well as management and leadership skills. The GDC defines that there must be a relationship between the outcomes required at the pre-registration stage of education and the standards a fully registered dental professional must meet to fulfil the regulatory requirements. Its role includes regulation of education and training provision ensuring it is fair, impartial, consistent and evidence-based. It con­ siders that the burden of regulation on the providers of education and training should be kept to the necessary minimum, through an approach that is targeted, proportionate, and informed by risk assessment. The GDC determines that an outcomes-centred approach should encourage innovation, particularly in the development of new approaches to teaching, learning and assessment but should recognize the range of variables in the delivery of education, e.g. of oral health needs, service structures, learning and teaching styles, and forms of team working. Additionally, it determines that the learning outcomes should be responsive to changes in public expectations and evolve in the light of such changes. The GDC requirement regarding the aims of dental education The learning outcomes should reflect the knowledge, skills, attitudes and behaviours a registrant must have to practise safely, effectively and professionally in the relevant registration category. The aim is to develop a rounded professional who, in addition to being a competent clinician and/or technician, will have the range of professional skills required to begin working as part of a dental team and be well prepared for independent practice as a ‘safe beginner’. It is recognized that many newly qualified dentists go on to complete further training and must do so in order to practise in the NHS as practice principals. Dental professionals also work outside the NHS, so the GDC has a responsibility to set learning outcomes which prepare all potential registrants for safe and independent practice, from the first day of registration. Independent practice does not mean working alone or in isolation, but within the context of the wider healthcare team. The skills the GDC requires of registrants are covered in the following domains: • Clinical – the range of skills required to deliver direct care, where registrants interact with patients, and also the essential technical skills, carried out without direct interaction with patients but supports their care (for example, by dental technicians). 76 • • Communication – the skills involved in effectively interacting with patients, their representatives, the public and colleagues as well as the ability to record appropriate information to record accurately patient care provided and proposed. Professionalism – the knowledge, skills and attitudes and behaviours required to practise in an ethical and appropriate way, putting patients’ needs first and promoting confidence in the dental team. Management and Leadership – the skills and knowledge required to work effectively as a dental team, effective management of time and resources contributing to professional practice. Additionally having the range of skills required to deliver direct care, where registrants interact with patients as well as having the essential technical skills carried out in the absence of patients which support their care (for example the work of dental technicians). • • C L I N I C A L D E N T I S T RY An important element of being ready for practice is the ability of an individual to recognize the responsibility that comes with being a dental registrant delivering patient care. Of particular importance is being able to judge one’s own limitations and to work within them. All dental professionals must understand the principles of evidence-based practice and possess the ability to make appropriate decisions on patient care using this approach. The GDC’s Learning Outcomes form the foundation upon which a registrant will be expected to develop and maintain their knowledge and skills throughout their professional career, to become fully proficient. The outcomes for the training of dental professionals derive from and are consistent with the GDC’s Standards for the Dental team and the requirements for lifelong learning. Dental professionals are part of a wider dental and healthcare team having the aim of delivering high quality patient care that puts patients’ needs first, but also taking account of their current and future oral health needs. See GDC website for further information. Dental undergraduate student fitness to practise Dental students in training are expected to have the same professional and ethical standards as registrants; assessing students’ fitness to practise as a registrant is part of undergraduate dental courses and is noted in the GDC’s publication available at http://www.gdc-uk.org/ aboutus/education/Pages/Education-sector.aspx. The GDC Guidance describes the following: 1. The types of professional behaviour and health standards expected of dental students; 2. How fitness to practise can affect registration; T h e dental tea m • 77 3. When and how to make decisions about fitness to practise; and 4. The key elements in student fitness to practise procedures. Which includes: • • • • • • • Principles of professional behaviour Putting patients’ interests first and acting to protect them Respecting patients’ dignity and choices Protecting the confidentiality of patients’ information Co-operating with other members of the dental team and other healthcare colleagues in the interests of patients Maintaining professional knowledge and competence Being trustworthy. It also requires that providers of registerable qualifications must have procedures in place to: 1. Identify as soon as possible students whose behaviour or health gives concern for the safety of patients or colleagues. 2. Take action to help students to improve their behaviour, or make reasonable adjustments where necessary to take account of health issues. 4. Make sure that students who are a risk to patients are identified as early as possible and appropriate action is taken to ensure that either deficiencies are corrected or the student is excluded from the course. It re-iterates the importance of the GDC Guidance, ‘Standards for the Dental Team’: 1. Students’ behaviour should be measured against the principles set out in ‘Standards for the Dental Team’; 2. If a student’s behaviour falls below these expected standards, the education provider should consider if this amounts to a fitness to practise concern and whether this behaviour warrants consideration through the formal fitness to practise procedures. Potential areas of concern identified in the Guidance are: Criminal conviction or caution including but not restricted to: • Child pornography • Theft • Financial fraud • Possession of illegal substances • Child abuse or any other abuse • Physical violence Drug or alcohol misuse: • • • • Drink driving Alcohol consumption that affects clinical work or environment Dealing, possessing or misusing drugs even if there are no legal proceedings Assault, aggressive, violent or threatening behaviour 78 • • • • Physical violence Bullying Abuse C L I N I C A L D E N T I S T RY Persistent inappropriate attitude or behavior: • • • • Uncommitted to work Neglect of administrative tasks Poor time management Non-attendance Cheating or plagiarizing: • • • Cheating in exams or completion of logbooks Passing off others’ work as one’s own Forging a supervisor’s name on assessments Dishonesty or fraud, including dishonesty outside the professional role: • • • Falsifying research Financial fraud Fraudulent CVs or other documents Unprofessional behaviour or attitudes • • • • • • • Breach of confidentiality Misleading patients about their care or treatment Culpable involvement in a failure to obtain proper consent from a patient Sexual harassment Inappropriate examinations or failure to keep appropriate boundaries in behaviour Persistent rudeness to patients, colleagues or others Unlawful discrimination Health concerns including mental health issues: • • • Failure to seek medical attention or other support Refusal to follow medical advice or care plan including monitoring/ reviews Failure to recognize limits and abilities. Dental postgraduate education and training Postgraduate dental deans influence training opportunities and standards in NHS Trusts and Health Boards as well as in Dental Foundation training practices. They also play a role in developing national policies on postgraduate dental education and implementation of new initiatives. Their role covers dental foundation and speciality training, national recruitment and retention in primary and secondary care. They are involved in leading the development of T h e dental tea m • 79 the dental workforce, including dental care professionals, as well as managing the provision and quality assurance of Continuing Professional Development (CPD) for dental teams. They also provide support for doctors and dentists in difficulty. The UK Committee of Postgraduate Dental Deans and Directors website is: http://www.copdend.org/. Specialist dentists Specialist dentists are those registered as specialists by the GDC who fulfil certain criteria and thus have a right to call themselves specialists in particular areas of dentistry. Specialists are sometimes responsible for treatments not taught in the undergraduate education and training, such as operations outside of the oral tissues alone, dental implants, cleft palate, and cancer. As of 2015, the GDC maintained 13 Specialist Lists in Distinctive Branches of Dentistry (Box 4.2) to enable patients to identify specialist dentists. Not all areas in dentistry that may be thought of as specialties are recognized as such by the GDC. Additionally, 2014 saw the commencement of a public consultation by the GDC into Standards for Specialty Education. The dental team The General Dental Council’s Definition of Illegal Practice (GDC, 2005) states: The Dentists Act 1984 makes it a criminal offence for a person who is not a registered dentist or a registered dental care professional to practise dentistry, or hold themselves out – whether directly or by implication – as practising or as being prepared to practise dentistry. By law, all registrants are individually accountable to the GDC, and dentists are additionally accountable as leaders of the dental team (http://www.gdc-uk.org/Dentalprof essionals/Education/ Documents/DevelopingTheDentalTeam.pdf). Clinical dental care in the UK can only be provided only by GDC-registered: • • • • • Dentists Dental therapists Orthodontic therapists Dental hygienists Clinical dental technicians. assisted by: • • Dental nurses Dental technicians. 80 • C L I N I C A L D E N T I S T RY Box 4.2 The GDC specialist lists in distinctive branches of dentistry Dental and Maxillofacial Radiology Involves all aspects of medical imaging which provide information about anatomy, function and diseased states of the teeth and jaws. Dental Public Health This is a non-clinical specialty involving the science and art of preventing oral diseases, promoting oral health to the population rather than the individual. It involves the assessment of dental health needs and ensuring dental services meet those needs. Endodontics Concerned with the cause, diagnosis, prevention and treatment of diseases and injuries of the tooth root, dental pulp, and surrounding tissue. [Endodontics is part of Restorative Dentistry.] Oral Medicine Concerned with the oral health care of patients with chronic recurrent and medically related disorders of the mouth and with their diagnosis and nonsurgical management. [Oral Medicine is the specialty of dentistry that sits at the interface between dentistry and medicine. Many Oral Medicine specialists have dental and medical qualifications, and both were requirements for entry to training that led to appointment as a Consultant in Oral Medicine. The requirement for a formal medical qualification has now ceased. This all reflects that the specialty had its origins in dentistry, but has evolved to formally encompass medical aspects of care.] Oral Microbiology Diagnosis and assessment of facial infection – typically bacterial and fungal disease. This is a clinical specialty undertaken by laboratory-based staff, who provide reports and advice based on interpretation of microbiological samples. Oral and Maxillofacial Pathology Diagnosis and assessment made from tissue changes characteristic of disease of the oral cavity, jaws and salivary glands. This is a clinical specialty undertaken by laboratory based personnel. [It includes the scientific study of the causes and effects of disease in the oral and maxillo-facial complex, an understanding of which is essential for diagnosis and for the development of appropriate treatments and preventative programmes.] Oral Surgery Deals with the treatment and ongoing management of irregularities and pathology of the jaw and mouth that require surgical intervention. This includes the specialty previously called Surgical Dentistry. T h e dental tea m • 81 Box 4.2 The GDC specialist lists in distinctive branches of dentistry—cont’d ‘Oral & Maxillofacial Surgery’, ‘Maxillofacial Surgery’ and ‘Dental, Oral and Maxillofacial Surgery’ are EU-recognized medical specialties in the member states. Maxillofacial Surgery does not require dental training but the other two require a fully recognized five-year dental undergraduate training. The UK General Medical Council recognizes ‘Oral & Maxillofacial Surgery’ as a medical specialty concerned with the diagnosis and treatment of diseases affecting the mouth, jaws, face and neck, that sits at the interface between dentistry and medicine. Oral and Maxillofacial Surgery specialists are registered on the Register of the General Medical Council but usually have dental and medical qualifications. This reflects that the specialty had its origins in dentistry, but has evolved to formally encompass surgical aspects of care.] Orthodontics The development, prevention, and correction of irregularities of the teeth, bite and jaw. Paediatric Dentistry Concerned with comprehensive therapeutic oral health care for children from birth through adolescence, including care for those who demonstrate intellectual, medical, physical, psychological and/or emotional problems. Periodontics Diagnosis, treatment and prevention of diseases and disorders (infections and inflammatory) of the gums and other structures around the teeth. [Periodontics is part of Restorative Dentistry.] Prosthodontics Replacement of missing teeth and the associated soft and hard tissues by prostheses (crowns, bridges, dentures) which may be fixed or removable, or may be supported and retained by implants. [Prosthodontics is part of Restorative Dentistry.] Restorative Dentistry Deals with the restoration of diseased, injured, or abnormal teeth to normal function. Includes all aspects of Endodontics, Periodontics and Prosthodontics. [At the time of going to print, the GDC is seeking views on how it regulates the practice of Implant Dentistry.] Special Care Dentistry Special Care Dentistry is concerned with the improvement of the oral health of individuals and groups in society who have a physical, sensory, intellectual, mental, medical, emotional or social impairment or disability or, more often, a combination of these factors. It pertains to adolescents and adults. http://dentalebooks.com 82 • C L I N I C A L D E N T I S T RY Scope of practice The scope of practice of members of the dental team is outlined in detail in the GDC document Scope of Practice: http://www.gdc-uk .org/dentalprofessionals/standards/documents/scope%20of%20 practice%20september%202013%20(3).pdf: Dentists Dentists are registered dental professionals who carry out all the treatment listed in the document, Scope of Practice. Dentists can carry out all of the treatments listed in this document. A dentist can also undertake the following if trained, competent and indemnified: • • • • • • • • • • • • • Diagnose disease Prepare comprehensive treatment plans Prescribe and provide endodontic treatment on adult teeth Prescribe and provide fixed orthodontic treatment Prescribe and provide fixed and removable prostheses Carry out oral surgery Carry out periodontal surgery Extract permanent teeth Prescribe and provide crowns and bridges Provide conscious sedation Carry out treatment on patients who are under general anaesthesia Prescribe medicines as part of dental treatment Prescribe and interpret radiographs. Additional skills which a dentist can develop: • • Providing implants Providing non-surgical cosmetic injectables. Dental nurses Dental nurses are registered dental professionals who provide clinical and other support to registrants and patients. A dental nurse can undertake the following if trained, competent and indemnified: • • • • • • Prepare and maintain the clinical environment, including the equipment. Carry out infection prevention and control procedures to prevent physical, chemical and microbiological contamination in the surgery or laboratory Record dental charting and oral tissue assessments carried out by other registrants Prepare, mix and handle dental bio-materials Provide chairside support to the operator during treatment Keep full, accurate and contemporaneous patient records http://dentalebooks.com T h e dental tea m • • • • • • • 83 Prepare equipment, materials and patients for dental radiography Process dental radiographs Monitor, support and reassure patients Give appropriate patient advice Support the patient and their colleagues if there is a medical emergency Make appropriate referrals to other health professionals. Additional skills dental nurses can develop include: • • • • • • • • Further skills in oral health education and oral health promotion Assisting in the treatment of patients who are under conscious sedation Further skills in assisting in the treatment of patients with special needs Further skills in assisting in the treatment of orthodontic patients Intra- and extra-oral photography Pouring, casting and trimming study models Shade taking Tracing cephalometric radiographs Additional skills carried out on prescription from, or under the direction of another registrant that a dental nurse can develop: • • • • • • • • • • Taking radiographs Placing rubber dam Measuring and recording plaque indices Removing sutures after the wound has been checked by a dentist Constructing occlusal registration rims and special trays Repairing the acrylic component of removable appliances Applying topical anaesthetic to the prescription of a dentist Constructing mouthguards and bleaching trays to the prescription of a dentist Constructing vacuum formed retainers to the prescription of a dentist Taking impressions to the prescription of a dentist or a CDT (where appropriate). Dental nurses may also apply fluoride varnish either on prescription from a dentist or direct as part of a structured dental health programme. Dental nurses do not diagnose disease or treatment plan. All other skills are reserved to one or more of the other registrant groups. Orthodontic therapists Orthodontic therapists are registered dental professionals who carry out certain parts of orthodontic treatment under the prescription from a dentist. http://dentalebooks.com 84 • C L I N I C A L D E N T I S T RY An orthodontic therapist can undertake the following if trained, competent and indemnified: • • • • • • • • • • • • • • • • • • • • • • Clean and prepare tooth surfaces ready for orthodontic treatment Identify, select, use and maintain appropriate instruments Insert passive removable orthodontic appliances Insert removable appliances activated or adjusted by a dentist Remove fixed appliances, orthodontic adhesives and cement Identify, select, prepare and place auxiliaries Take impressions Pour, cast and trim study models Make a patient’s orthodontic appliance safe in the absence of a dentist Fit orthodontic headgear Fit orthodontic face bows which have been adjusted by a dentist Take occlusal records including orthognathic facebow readings Take intra and extra-oral photographs Place brackets and bands Prepare, insert, adjust and remove archwires previously prescribed or, where necessary, activated by a dentist Give advice on appliance care and oral health instruction Fit tooth separators Fit bonded retainers Carry out Index of Orthodontic Treatment Need (IOTN) screening either under the direction of a dentist or direct to patients Make appropriate referrals to other healthcare professionals Keep full, accurate and contemporaneous patient records Give appropriate patient advice. Additional skills which orthodontic therapists can develop include: • • • • Applying fluoride varnish to the prescription of a dentist Repairing the acrylic component part of orthodontic appliances Measuring and recording plaque indices Removing sutures after the wound has been checked by a dentist Orthodontic therapists do not: • • • • • • • Modify prescribed archwires Give local analgesia Remove sub-gingival deposits Re-cement crowns Place temporary dressings Diagnose disease Treatment plan. These tasks are reserved to dental hygienists, dental therapists or dentists. http://dentalebooks.com T h e dental tea m • 85 Orthodontic therapists do not carry out laboratory work other than that listed above, such care and treatment is reserved to dental technicians and clinical dental technicians. Dental hygienists Dental hygienists are registered dental professionals who help patients maintain their oral health by preventing and treating periodontal disease and promoting good oral health practice. They carry out treatment direct to patients or under prescription from a dentist. A dental hygienist can undertake the following if trained, competent and indemnified: • • • • • • • • • • • • • • • • • • • • • • • • Provide dental hygiene care to a wide range of patients Obtain a detailed dental history from patients and evaluate their medical history Carry out a clinical examination within their competence Complete periodontal examination and charting and use indices to screen and monitor periodontal disease Diagnose and treatment plan within their competence Prescribe radiographs Take, process and interpret various film views used in general dental practice Plan the delivery of periodontal care for patients Give appropriate patient advice Provide preventive oral care to patients and liaise with dentists over the treatment of caries, periodontal disease and tooth wear Undertake supra-gingival and sub-gingival scaling and root surface debridement using manual and powered instruments Use appropriate antimicrobial therapy to manage plaque-related diseases Adjust restored surfaces in relation to periodontal treatment Apply topical treatments and fissure sealants Give patients advice on how to stop smoking Take intra- and extra-oral photographs Give infiltration and inferior dental block analgesia Place temporary dressings and re-cement crowns with temporary cement Place rubber dam Take impressions Provide care of implants and treatment of peri-implant tissues Identify anatomical features, recognize abnormalities and interpret common pathology Carry out oral cancer screening If necessary, refer patients to other healthcare professionals http://dentalebooks.com 86 • • • Keep full, accurate and contemporaneous patient records If working under prescription, vary the detail but not the direction of the prescription according to patient needs. C L I N I C A L D E N T I S T RY Additional skills which dental hygienists can develop include: • • • Tooth whitening to the prescription of a dentist Administering inhalation sedation Removing sutures after the wound has been checked by a dentist. Dental hygienists do not: • • • • Restore teeth Carry out pulp treatments Adjust un-restored surfaces Extract teeth. These and other skills are reserved to orthodontic therapists, dental technicians, clinical dental technicians or dentists. Dental therapists Dental therapists are registered dental professionals who carry out certain items of dental treatment direct to patients or under prescription from a dentist. A dental therapist can undertake the following if trained, competent and indemnified: • • • • • • • • • • • • • • • • Obtain a detailed dental history from patients and evaluate their medical history Carry out a clinical examination within their competence Complete periodontal examination and charting and use indices to screen and monitor periodontal disease Diagnose and treatment plan within their competence Prescribe radiographs Take, process and interpret various film views used in general dental practice Plan the delivery of care for patients Give appropriate patient advice Provide preventive oral care to patients and liaise with dentists over the treatment of caries, periodontal disease and tooth wear Undertake supra-gingival and sub-gingival scaling and root surface debridement using manual and powered instruments Use appropriate antimicrobial therapy to manage plaque-related diseases Adjust restored surfaces in relation to periodontal treatment Apply topical treatments and fissure sealants Give patients advice on how to stop smoking Take intra- and extra-oral photographs Give infiltration and inferior dental block analgesia http://dentalebooks.com T h e dental tea m • • • • • • • • • • • • • • 87 Place temporary dressings and re-cement crowns with temporary cement Place rubber dam Take impressions Provide care of implants and treatment of peri-implant tissues Carry out direct restorations on primary and secondary teeth Carry out pulpotomies on primary teeth Extract primary teeth Place pre-formed crowns on primary teeth Identify anatomical features, recognize abnormalities and interpret common pathology Carry out oral cancer screening If necessary, refer patients to other healthcare professionals Keep full, accurate and contemporaneous patient records If working on prescription, vary the detail but not the direction of the prescription according to patient needs. For example the number of surfaces to be restored or the material to be used. Additional skills which dental therapists can develop include: • • • Carrying out tooth whitening to the prescription of a dentist Administering inhalation sedation Removing sutures after the wound has been checked by a dentist. All other skills are reserved to orthodontic therapists, dental technicians, clinical dental technicians or dentists. Dental technicians Dental technicians are registered dental professionals who make dental devices to a prescription from a dentist or a clinical dental technician. They also repair dentures direct to members of the public. A dental technician can undertake the following if trained, competent and indemnified: • • • • • • • • Review cases coming into the laboratory to decide how they should be progressed Work with the dentist or clinical dental technician on treatment planning and outline design Give appropriate patient advice Design, plan and make a range of custom-made dental devices according to a prescription Modify dental devices including dentures, orthodontic appliances, crowns and bridges according to a prescription Carry out shade taking Carry out infection prevention and control procedures to prevent physical, chemical and microbiological contamination in the laboratory Keep full and accurate laboratory records http://dentalebooks.com 88 • • Verify and take responsibility for the quality and safety of devices leaving a laboratory Make appropriate referrals to other healthcare professionals Dental technicians can see patients direct to repair dentures. • • C L I N I C A L D E N T I S T RY Additional skills which dental technicians can develop include: • • Working with a dentist in the clinic, assisting with treatment by helping to fit attachments at chairside. Working with a dentist or a clinical dental technician in the clinic, assisting with treatment by: • • • • • • • • Taking impressions Recording facebows Carrying out intra-oral and extra-oral tracing Carrying out implant frame assessments Recording occlusal registrations Tracing cephalometric radiographs Carrying out intra-oral scanning for CAD/CAM Taking intra- and extra-oral photographs. Dental technicians do not work independently in the clinic to: • • • • Perform clinical procedures related to providing removable dental appliances Carry out independent clinical examinations Identify abnormal oral mucosa and related underlying structures Fit removable appliances. Dental technicians do not provide treatment for or give advice to patients in the ways that are described under the sections describing areas of practice reserved for dental hygienists, dental therapists, orthodontic therapists or dentists. Clinical dental technicians (CDTs) Clinical dental technicians are registered dental professionals who provide complete dentures direct to patients and other dental devices on prescription from a dentist. They are also qualified dental technicians. Patients with any natural teeth or implants must see a dentist before the CDT can begin treatment. CDTs refer patients to a dentist for the dentist to provide a treatment plan for the CDT to carry out or if the CDT is concerned about the patient’s oral health. Clinical dental technology builds on dental technology. A CDT can undertake the following if trained, competent and indemnified: • • • Prescribe and provide complete dentures direct to patients Provide and fit other dental devices on prescription from a dentist Take detailed dental history and relevant medical history http://dentalebooks.com T h e dental tea m • • • • • • • • • • • 89 Perform technical and clinical procedures related to providing removable dental appliances Carry out clinical examinations within their scope of practice Take and process radiographs and other images related to providing removable dental appliances Distinguish between normal and abnormal consequences of ageing Give appropriate patient advice Recognize abnormal oral mucosa and related underlying structures and refer patients to other healthcare professionals if necessary Fit removable appliances Provide sports mouthguards Keep full, accurate and contemporaneous patient records Vary the detail but not the direction of a prescription according to patient needs. Additional skills which CDTs can develop include: • • • • • • • Oral health education Re-cementing crowns with temporary cement Providing anti-snoring devices on the prescription of a dentist Removing sutures after the wound has been checked by a dentist Prescribing radiographs Replacing implant abutments for removable dental appliances on prescription from a dentist Providing tooth whitening treatments on prescription from a dentist. All other skills are reserved to dental hygienists, dental therapists, orthodontic therapists or dentists. Direct access to dental care professionals The GDC defines ‘Direct access’ as giving patients the option to see a dental care professional (DCP) without having first seen a dentist and without a prescription from a dentist. Thus: • • • • Dental nurses can participate in preventative programmes without the patient having to see a dentist first. Dental hygienists and dental therapists will be able to see patients direct. Orthodontic therapists can carry out Index of Orthodontic Treatment Need (IOTN) screening without the patient having to see a dentist Clinical dental technicians can see patients direct only for the provision and maintenance of full dentures. At the time of publication direct access to dental care professionals is not permitted under NHS arrangements in the UK. http://dentalebooks.com 90 • C L I N I C A L D E N T I S T RY Table 4.1 Dentists who can practise in the UK Basic dental training Qualification requirements for GDC registration At a UK University A GDC recognized 5 years undergraduate education and training programme leading to a Bachelor of Dental Surgery (BDS) or other recognized dental qualification the GDC gives full registration on graduation; there is no pre-registration year as in medicine in the UK although UK dental graduates are required to undertake postgraduate professional training (VDP or DF1 and DF2) prior to being able to be a principal dentist providing NHS general dental services. At a EEA Dental School The registrant’s home country’s recognized basic dental qualification such as Doctor of Dental Surgery (DDS) etc. Dental school outside EEA The Overseas Registration Examination (ORE) permits dental graduates form dental schools outside of the EEA not eligible for full registration to register with the GDC and to practise dentistry unsupervised in the UK. The ORE tests the clinical skills and knowledge of these dentists. Others who can register with the GDC and practise are those with a qualification gained before 01/01/01 from Hong Kong, Singapore, Malaysia, South Africa, New Zealand and Australia with the exception of BChD MEDUNSA, BDS awarded between 01/01/97 to 31/12/00 and BChD Western Cape awarded before 31/12/97. Graduates from outside of the EEA are required either to undertake postgraduate professional training (VDP or DF1 and DF2) or demonstrate that they have equivalence to this training prior to being able to be a principal dentist providing NHS general dental services. Temporary Registration Temporary registration allows dentists who are not eligible for full registration to practise dentistry in the UK but only in supervised posts for training, teaching, or research purposes, and only for a limited period. An overseas qualified dentist can apply for and be granted temporary registration in specific approved posts in addition to undertaking the overseas registration examination (ORE) if they hold a dental qualification from a university which is recognized by NARIC UK (National Academic Recognition Information Centre UK). NARIC UK is the UK’s National Agency responsible for providing information an opinion on academic, vocational and professional qualifications from across the world. Eligibility for these training posts is also dependent upon obtaining a UK Border Agency visa where this is required. http://dentalebooks.com T h e dental tea m • 91 Table 4.2 Bodies other than GDC particularly relevant to UK dentistry Body Main functions URL British Dental Association A national professional association for dentists https://www.bda.org/ British Dental Nurses Association A national professional association for dental nurses http://badn.org.uk/ Royal Colleges of Surgeons Professional associations for dentists and DCPs which also offer education, examinations and higher qualifications http://www.rcseng.ac.uk/fds http://www.rcsed.ac.uk/ examinations/dental.aspx http://www.rcpsg.ac.uk/ dentistry.aspx For fuller details see https://www.gdc-uk.org/Dentalprofessionals/ Standards/Pages/directaccessqas.aspx Registered dentists According to the GDC, all registered dentists are legally entitled to practise any clinical aspect of dentistry, such as cosmetic surgery, provided they undertake only procedures within their competence and do not use the title of ‘specialist’ unless entitled to do so. Dentists who can practise in the UK Table 4.1 outlines who can practise in the UK. Table 4.2 gives details of bodies important in dentistry. Specialists See Box 4.2 for current GDC – recognised Specialities in Dentistry. http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Law, ethics and quality dental care Practising lawfully, professionally and ethically 93 Continuing Professional Development (CPD) 98 Professionalism and fitness to practise 100 Treating patients 106 Record keeping – clinical records 110 5 Equality and diversity 112 Quality dental care 112 Evidence-based dentistry 115 Clinical effectiveness 116 Complaints 117 Underperformance 118 Conclusion 119 Practising lawfully, professionally and ethically Patients have a right to expect that those providing dental care and treatment will do so safely, legally, appropriately and with a suitable degree of skill and attention. In the UK and most other jurisdictions there is a requirement for dentists and other members of the dental team to be registered with the regulatory authority – in the UK this is the General Dental Council (GDC) – and must also hold adequate indemnity or liability insurance so that patients can be compensated in the event of mishap. In the UK the practice of dentistry is defined within the Dentists Act 1984. Illegal practice can result in prosecution under criminal law. It is essential therefore that all dental team members understand their regulatory requirements and abide by them. Legislation Dentistry in the United Kingdom is governed by the Dentists Act 1984 and the regulatory authority is the General Dental Council. If the GDC considers that patients could be placed at risk by a registrant, it has the power to withdraw that individual’s licence to practise or impose restrictions upon their practice. In addition to the Dentists Act, legislation impinges on virtually all aspects of dental practice and it is beyond the scope of this book to detail the implications of each individual Act or item of secondary legislation. Examples of legislation of particular significance in dental practice are given in Table 5.1. All dentists and Dental Care Professionals (DCPs) (see Chapter 4) must be aware of the implications of such legislation. http://dentalebooks.com 94 • C L I N I C A L D E N T I S T RY TABLE 5.1 Laws associated with the governance and practice of dentistry Adults with Incapacity Act (Scotland) 2000 Consent to Medical Treatment Act 2008 Cosmetic Product Regulations 1996, Cosmetic Product (Safety) Regulations 2008, Cosmetic Product (Enforcement) Regulations 2013 Data Protection Act 1998 Dentists Act 1984 Disability Discrimination Act 1995 Employment Law Equality Act 2010 Freedom of Information (Scotland) Act 2002 Freedom of Information Act 2000 Health Act 1999 Health and Safety Legislation Health and Social Care Act 2001 Ionising Radiation Regulations 1999 IR(ME)R 2000 Mental Capacity Act 2005 National Health Service (Scotland) Act 1978 National Health Service 1977 Smoking Health and Social Care (Scotland) Act 2005 The Common Law, Consumer Law, Criminal Law The Francis Report (Report of the Mid Staffordshire NHS Foundation Trust Public Inquiry, chaired by Robert Francis QC 2013. http://www.midstaffspublicinquiry.com/report The Law of Consent and Negligence Employment legislation also applies to those employing and directing dental personnel. Ethical guidance, standards and regulation In 1998, the General Dental Council (GDC) replaced their previous ethical guidance publication, The Red Book, with a much more prescriptive guidance, Maintaining Standards. This was, in turn, replaced on 1 June 2005 with a much less prescriptive guidance called Guidance for Dental Professionals. In September 2013 the GDC issued new ethical guidance entitled Standards for the Dental Team. The 2013 guidance, Standards for the Dental Team (Figure 5.1) is more prescriptive and reflects changes in the Dentists Act which now http://dentalebooks.com L a w, et h ics and q u ality dental care • 95 A B Figure 5.1 Extracts from the GDC document, Smile, Your dental team have check-ups too. requires all dentists, dental therapists, dental hygienists, orthodontic dental therapists, dental nurses, dental technicians and clinical dental technicians to register with the GDC and maintain their registration with the Regulator (the GDC) in order to continue to practise as a dental professional (see Chapter 4). Standards for the Dental Team also makes clear the responsibility of registrants in respect of their duty to ensure that all those involved in patient care have an ethical duty toward patients even if those http://dentalebooks.com 96 • C L I N I C A L D E N T I S T RY individuals are not registrants or required to be registrants, e.g. practice administrative staff, etc. The document sets out the standards of conduct, performance and ethics that govern you as a dental professional. It specifies the principles, standards and guidance which apply to all members of the dental team. It also sets out what patients can expect from their dental professionals. There are nine principles that the GDC determines that dental professionals must keep to at all times and to emphasize the change in tone of the 2013 guidance, it is emphasized that in the document ‘must’ is used where the duty is compulsory and ‘should’ is used where the duty would not apply in all situations and where there are exceptional circumstances outside of the registrant’s control that could affect whether or how the registrant can comply with the guidance. Should is also used where the GDC is providing an explanation of how the registrant will meet the overriding duty. The nine principles dental registrants must keep 1. 2. 3. 4. 5. 6. 7. Put patients’ interests first Communicate effectively with patients Obtain valid consent Maintain and protect patients’ information Have a clear and effective complaints procedure Work with colleagues in a way that is in patients’ best interests Maintain, develop and work within your professional knowledge and skills 8. Raise concerns if patients are at risk 9. Make sure that your personal behaviour maintains patients’ confidence in you and the dental profession. The nine sections of the Standards for the Dental Team reflect the nine principles and detail what a patient has a right to expect in relation to the nine principles and what registrants must do to comply with the standards. It is obviously beyond the scope of this book to go into a more detailed description of the standards but it must be prudent for every registrant to obtain a copy of the Standards for the Dental Team to read it, discuss with colleagues the requirements and ensure at all times that they are complying implicitly in what they must do. Duty of candour On 12 December 2014 The General Dental Council (GDC) welcomed the report by the Professional Standards Authority (PSA) on progress made in developing a consistent approach amongst the Regulators to candour, promising to issue guidance to registrants at a future date. With the other healthcare regulators in the UK the GDC is committed http://dentalebooks.com L a w, et h ics and q u ality dental care • 97 to promoting ‘the duty of candour’ to its registrants, students and dental patients. The GDC, with the UK regulators, emphasized the importance of candour for all professionals working with patients stating that every healthcare professional must be open and honest with patients when something goes wrong with their treatment or care which causes, or has the potential to cause, harm or distress. It added that healthcare professionals must be open and honest with their colleagues, employers and relevant organizations; they must take part in reviews and investigations when requested. The Frances Report defined the duty of candour as: ‘Any patient harmed by the provision of a healthcare service is informed of the fact and an appropriate remedy offered, regardless of whether a complaint has been made or a question asked about it’. All dental registrants must therefore comply with the Professional Duty of Candour: 1. All dental registrants must be open and honest with patients when something goes wrong with their treatment or care which causes, or has the potential to cause, harm or distress. 2. This means that dental registrants must: a. Tell the patient (or, where appropriate, the patient’s advocate, carer or family) when something has gone wrong; b. Apologize to the patient (or, where appropriate, the patient’s advocate, carer or family); c. Offer an appropriate remedy or support to put matters right (if possible); and d. Explain fully to the patient (or, where appropriate, the patient’s advocate, carer or family) the short- and long-term effects of what has happened. 3. Dental registrants must be open and honest with their colleagues, employers and relevant organizations and must take part in reviews and investigations when requested. 4. Dental registrants must be open and honest with Regulators, raising concerns where appropriate. Dental registrants must support and encourage each other to be open and honest and must not stop someone who has concerns from raising concerns. The General Dental Council’s guidance to patients Every piece of correspondence from the GDC contains in the header what the GDC perceives is its role: ‘Protecting Patients’, ‘Regulating the Dental Team’. In addition to producing ethical guidance for dentists, the GDC also provides guidance to patients. ‘Smile’ the GDC’s document for patients (Figure 5.1) emphasizes its role as regulator and in addition to advising patients on what they http://dentalebooks.com 98 A • C L I N I C A L D E N T I S T RY B C Figure 5.2 Continuing Professional Development (CPD). have a right to expect when receiving dental care and treatment advises on what patients should do if they are dissatisfied with the care and treatment that they have received. Registrants should therefore be aware of the consequences of not adhering to the ethical guidance and the effect that failure to comply might have upon their licence to practise. Standards for the dental team and how they are upheld The prime statutory duty of the General Dental Council is to maintain the Dentists Register and Dental Care Professionals Register; if a registrant is not on the appropriate register they cannot practise in the United Kingdom. Education for dental registrants The GDC governs the educational requirements to train registrants and visit dental schools and training institutions to ensure that the training is appropriate and that there is rigorous assessment to ensure that registrants have been assessed as safe to practice – ‘safe beginners’ once their initial training to obtain registration is complete. The GDC determines the training, learning outcomes and assessment of those providing dental education; it also has teams of inspectors who visit the dental schools and education providers to provide assurance. Details of the requirements can be found on the GDC’s website and in the documents illustrated in Figure 5.2. Continuing Professional Development (CPD) It is a requirement that all registrants maintain and update their professional knowledge throughout their practising life; this is http://dentalebooks.com L a w, et h ics and q u ality dental care • 99 achieved by Continuing Professional Development (CPD). In the case of dental registrants, the CPD requirement is laid down in law. Definition of CPD The GDC defines CPD as follows: ‘CPD for dental professionals is defined in law as lectures, seminars, courses, individual study and other activities that can be included in your CPD record if it can be reasonably expected to advance your professional development as a dentist or dental care professional and is relevant to your practice or intended practice’. The GDC cites the following as examples of what amongst other educational and training initiatives comprises CPD: • • • • • • • Courses and lectures Training days Peer review Clinical audit Reading journals Attending conferences E-learning activity. The GDC website (www.gdc-uk.org) gives suggestions on how registrants might fulfil their CPD requirements. CPD requirements for registrants The GDC publishes a booklet outlining the requirements for CPD (Continuing Professional Development for dental professionals) and how these should be achieved, available on the website (www.gdc-uk.org). At the time of publication of this book, the CPD requirements for dentists and dental care professionals were as follows: Minimum CPD hours Registrants are required to undertake a minimum stipulated amount of CPD both verifiable and non-verifiable during a five year CPD cycle dependent upon whether they are a dentist or a DCP. Verifiable CPD The GDC describes verifiable CPD as activity for which there is documentary evidence that the registrant has undertaken the CPD and that the CPD has: • • • Concise educational aims and objectives Clear anticipated outcomes Quality controls. Registrants must keep copies of the documentation confirming attendance at verifiable CPD; that documentation confirming the aims and objectives have been achieved; it must be produced for the http://dentalebooks.com 100 • C L I N I C A L D E N T I S T RY GDC if required. It would be prudent to keep such documentation safely and indefinitely as confirmation of having undertaken appropriate CPD is highly relevant if clinical ability, skill and experience is ever challenged. General or non-verifiable CPD General or non-verifiable CPD is defined as CPD that does not meet the verifiable requirements but reasonably advances a registrant’s development as a dental professional and is relevant to their practice or intended practice. CPD requirements – dentists For dentists first registered after 1 January 2002, their first 5-year CPD cycle began on or will begin on the 1 January in the year after they first registered. For dentists first registered between 1 January 1990 and 31 December 2001, their first five-year CPD cycle began on 1 January 2002. For dentists first registered between 1 January 1980 and 31 December 1989, their first five-year CPD cycle began on 1 January 2003. For dentists first registered before 31 December 1979, their first five-year CPD cycle began on 1 January 2004. Dentists are required to carry out at least 250 hours of CPD in each 5-year cycle; at least 75 of the hours are required to be verifiable CPD including core topics. Core topics are defined as medical emergencies (10 hours); disinfection and decontamination (5 hours); radiography and radiation protection (5 hours) as well as legal and ethical issues, complaints handling and early detection of oral cancer. CPD requirements – dental care professionals Dental care professionals’ first 5-year CPD cycle began or will begin on 1 August in the year after they first registered. Those who first registered prior to 31 July 2008 have a first 5-year CPD cycle start date of 1 August 2008. Dental care professionals must carry out at least 150 hours of CPD every five years of which a minimum of 50 hours require to be verifiable CPD including the six core topics: medical emergencies (10 hours); disinfection and decontamination (5 hours) (see Figure 5.4); radiography and radiation protection (5 hours) as well as legal and ethical issues, complaints handling and early detection of oral cancer. Professionalism and fitness to practise The General Dental Council places as great emphasis on a dental registrant behaving professionally as does the General Medical http://dentalebooks.com L a w, et h ics and q u ality dental care • 101 Council for doctors. However, what is meant by professionalism is extremely difficult to define. The three items comprising ‘patient expectations’ related to principle 9 in the GDC’s Standards for the Dental Team document state: Patients expect: • • • That all members of the dental team will maintain appropriate personal and professional behaviour. That they can have trust and confidence in registrants as dental professionals. That they can trust and have confidence in the dental profession. Professionalism is a core component of the undergraduate curriculum contained within the GDC’s requirements in its publication Preparing for Practice and is also noted in the postgraduate CPD requirements, Continued Professional Development. Wikipedia defines professionalism in the following way: A professional is a member of a profession. The term also describes the standards of education and training that prepare members of the profession with the particular knowledge and skills necessary to perform the role of that profession. In addition, most professionals are subject to strict codes of conduct enshrining rigorous ethical and moral obligations. Professional standards of practice and ethics for a particular field are typically agreed upon and maintained through widely recognized professional associations. Some definitions of ‘professional’ limit this term to those professions that serve some important aspect of public interest and the general good of society. This would appear to reflect the position taken by the GMC and GDC when these bodies determine how ‘professional’ and ‘professionalism’ should be interpreted. When a dental care professional fails to comply with the standards expected of registrants and the General Dental Council becomes aware, it has statutory powers enabling it to investigate and adjudicate on the registrant’s behaviour. The outcome is not meant to be punitive but can result in the registrant’s licence to practice being restricted, suspended or in some instances to erasure from the register. Fitness to practise procedures These procedures are laid down in legislation, The Dentists Act 1984; they are highly legalistic and may not be concluded for considerable periods of time, often causing registrants considerable stress and concern. Fitness to practise procedures may also be instigated in dental schools and training establishments; the GDC has determined that the http://dentalebooks.com 102 • C L I N I C A L D E N T I S T RY ethical guidance for dentists and dental care professionals applies equally to those training to join the profession. Fitness to practise procedures for students can result in sanctions including conditions, suspension or even expulsion from the course. Fitness to practise enquiries are not restricted to actions occurring in or related to the workplace; incidents involving the police, the criminal courts, etc. will frequently result in a referral by the body handling the case to the GDC. Those seeking GDC registration are required to sign a declaration regarding any previous convictions, regulatory difficulties, etc; such behaviour albeit prior to registration can still lead to the imposition of sanctions by the regulator or a refusal to register the individual. When a complaint is made to the General Dental Council concerning a registrant’s behaviour or fitness to practise, the GDC Registrar considers whether the complaint amounts to a possible allegation concerning a registrant’s fitness to practise and decides whether it should be passed to case workers or that no further action is required. Cases continuing are passed to case workers who after preliminary investigation consider the allegation at an Assessment Meeting and a decision is made as to whether the case merits referral to an Investigating Committee (IC) or, if there are immediate serious patient safety concerns, additionally referral to an Interim Orders Committee (IOC). The Investigating Committee The members of the Investigating Committee consider whether on the material received there is a realistic prospect (the realistic prospect test) of proving impairment of fitness to practise by a Practice Committee (Health, Performance or Conduct). If there is no likely finding of impairment the Investigating Committee may close the case with no further action or by issuing a letter of advice, a warning or a warning also published in the Register. The registrant can make written representation to the Investigating Committee but does not attend. The Investigating Committee may also refer the matter to an Interim Orders Committee when it considers this is necessary. The GDC website confirms that the Investigating Committee (IC) meets in private, with a quorum of three IC members, of which there shall be at least one registered dentist and one lay member; any meeting considering the fitness to practise of a Dental Care Professional (DCP) member requires at least one registered DCP committee member. The IC members for each session are drawn from an independently appointed pool of experience and trained members (both lay and registrant). The Interim Orders Committee The Interim Orders Committee (IOC) is a statutory GDC committee which determines if it is necessary to make an order affecting an http://dentalebooks.com L a w, et h ics and q u ality dental care • 103 individual’s registration for the protection of the public, in the public interest or in the interests of the registrant until such time as one of the Practice Committees has investigated and determined the case. The IOC does not investigate the allegations or undertake a fact finding exercise; it may: • • • Impose a suspension (up to 18 months with 6-monthly reviews) Impose conditions (up to 18 months with 6-monthly reviews) Decide that no order is necessary. As cases referred to the IOC are not investigated or the evidence tested by the IOC, the ‘bar’ to impose a finding is set relatively high to reduce the possibility of injustice. A case may be referred to the IOC at any stage including before or subsequent to being heard by an Investigating Committee. Hearings before the IOC are generally open to the public in the interests of openness and accountability of the profession; they may be heard in private where this is deemed by the IC to be in the interests of the parties, protection of the personal life of the registrant or if it is considered that publicity would prejudice the interests of justice. Membership of the IOC is drawn from the fitness to practise panellists who are both dental professionals and lay members. (Panellists sitting on an IOC are not permitted to sit on the same case at a Practice Committee). The Practice Committees The GDC has three Practice Committees to which cases may be referred by the Investigating Committee, the Health Committee, the Performance Committee and the Conduct Committee; perusal of the GDC’s data on the website confirms that the majority of cases are referred to Conduct Committees. Practice Committees are open to the public unless it is determined by the Committee that (as per IOCs above) it is appropriate for the hearing to be in private. The Health Committee The Health Committee considers cases where the allegation is that a dental care professional’s fitness to practise is or has been affected by a physical or mental condition. The Health Committee investigates the allegation and if found proven may: • • • • Conclude that the registrant’s fitness to practise is not impaired and close the case Issue a reprimand Impose conditions for up to 36 months (immediate conditions can be applied if required) Suspend the registrant for up to 12 months (with or without a review) (immediate suspension if required). http://dentalebooks.com 104 • C L I N I C A L D E N T I S T RY The Health Committee may also refer the case back to the Investigating, Performance or Conduct Committee. Many Health Committee investigations involve disclosure of confidential information regarding a registrant’s health and therefore, despite the fact that in the interests of public accountability The Health Committee may be held in public, given the sensitive nature of the matters under investigation many Health Committees are held in private for some or all of the Hearing. Members of Health Committees are drawn from the fitness to practise panellists who are both dental professionals and lay members. The Professional Performance Committee This committee considers allegations to assess whether a dental professional’s performance is deficient and if the deficiency amounts to an impairment of the registrant’s fitness to practise. The Professional Performance Committee can determine: • • • • • That the registrant’s fitness to practise is not impaired, and close the case That the issue of a reprimand is appropriate. That for up to 36 months conditions upon the registrant’s registration should be imposed and if appropriate immediate conditions can be applied. That the appropriate sanction is to suspend the registrant for up to 12 months (with or without a review prior to the cessation of the suspension. An immediate suspension may also be imposed. That the registrant’s name should be erased from the GDC Register. This Committee may also refer the case back or on to any of the other Practice Committees (PCs); as with the other PCs this Committee’s Hearings are generally held in public and its members are drawn from the fitness to practise panellists who are both dental professionals and lay members. The Professional Conduct Committee The Professional Conduct Committee (PCC) adjudicates whether an allegation referred amounts to misconduct and, if a finding of misconduct is found, if this amounts to an impairment of the registrant’s fitness to practise. The outcomes of a PCC can be: • • • To conclude that the registrant’s fitness to practise is not impaired and close the case. To issue a reprimand. To impose conditions for up to 36 months which may be applied immediately. http://dentalebooks.com L a w, et h ics and q u ality dental care • • • 105 To suspend the registrant for up to 12 months (with or without a review) to apply the suspension with immediate effect. To erase the registrant from the Register. This committee may also refer the case back or on to any of the other PCs; as with the other PCs this Committee’s Hearings are generally held in public and its members are drawn from the fitness to practise panellists who are both dental professionals and lay members. Appeals to decisions made by committees of the GDC Registrants may appeal against findings made against them by the Professional Committees of the GDC – to the High Court if registered in England, Wales or Northern Ireland, or to the Court of Session in Scotland. The Professional Standards Agency (formerly the Council for Healthcare Regulatory Excellence) oversees the GDC’s operation as the UK dental regulator and has the power to appeal against a decision of a GDC’s Professional Committee if it thinks the sanction too lenient. Support for registrants Receiving a letter from the GDC or any complaint can cause a registrant considerable distress; it is vitally important that all registrants are aware where they can get help and support when they are faced with difficulties. It is a requirement that all registrants have indemnity whilst they practise not only to provide indemnity from claims to pay compensation to an aggrieved patient but also to help and support registrants if an allegation or complaint is made against them. Most registrants in the UK receive indemnity and support either from the traditional suppliers, Dental Protection Ltd, the Dental Defence Union and the Medical and Dental Defence Union of Scotland but also from insurers and employers (especially if in government service). If a registrant receives an allegation or complaint from a patient or the GDC they should seek advice at a very early stage, and if appropriate contact their medical defence organization (or their insurer if that is their indemnifier) and their employer. The Dentists’ Health Support Trust and Programme (see Figure 5.3) Not only might a complaint or referral to the GDC or the Health Authority cause a registrant to feel unwell; but also up to 10% of registrants might have a health condition during their practising lives that might impinge on their fitness to practise. http://dentalebooks.com 106 • C L I N I C A L D E N T I S T RY Figure 5.3 The Dentists Health Support Programme and Trust. The Dentists’ Health Support Programme and Trust is run by dentists for dentists but also gives advice and support to all registrants if requested. The programme is audited and supported by a consultant psychiatrist and has two established, highly regarded co-ordinators who can be contacted by registrants, families or friends if they have concerns about their own or another registrant’s health that might affect their fitness to practise (dentistprogramme@gmail.com or 0207 224 4671). Treating patients Duty of care A patient has a right to expect that any treatment or care that they receive from dentists or DCPs, holding themselves out to have a particular skill, will be provided safely and to a standard that would be adjudged reasonable by those holding themselves out to have that particular skill. In other words not the best, nor the worst but reasonable skill and care, as judged by one’s peers. A General Dental Practitioner (GDP) would not be expected to have the same skill as a http://dentalebooks.com L a w, et h ics and q u ality dental care A B • 107 C Figure 5.4 Department of Health decontamination document. consultant or specialist but would be expected to know their own limitations and when it is appropriate to refer. Similarly, all registrants must only practise within their scope of practice as defined by the GDC and in accordance with their own skill and experience. It is necessary for all practices to have robust, tested, cross-infection control protocols, procedures and policies in place (see below and Figure 5.4). A failure to fulfil one’s duty of care to a patient leading to foreseeable harm (known in law as ‘causation’) might lead to a patient receiving recoverable damages resulting from a claim by a them in negligence. It is the duty of all dental professionals: • • • • • • To do good, not harm To always act in the patient’s best interests To put their patient’s best interests above their own To attempt, if possible, to relieve their patient’s pain and suffering To ensure that they have sufficient knowledge by way of training and enquiry of the patient or others associated with that patient’s care or well-being to ensure that they are acting in their patient’s best interests To be honest. Confidentiality All members of the dental team are bound by an ethical duty of confidentiality. It is essential that all staff have confirmed that they understand the need for confidentiality and have agreed to abide by the practice confidentiality protocol. Patients’ dental records are health records in terms of the Data Protection Act (DPA); health records are extremely personal and http://dentalebooks.com 108 • C L I N I C A L D E N T I S T RY sensitive. They can be held electronically or as paper files, and are kept in different formats by dental professionals both in the NHS and the private sector. It is imperative that they are kept confidential with adequate password protection on computers or USB sticks, etc., and in locked cabinets for paper records. Great care must be taken by all dental registrants to ensure that they do not discuss patients or patients’ care in any open forum and caution must be observed when requests for patient information is requested by relatives or others. The duty of confidentiality extends to all in the practice and it is vital that registrants regularly remind all practice staff regarding their confidentiality obligations. Particular caution must be exercised with social media which is now widely used by all sections of society; although social media can have a place in supporting health care, it is also very easy for registrants to unwittingly place items on social networks that could be construed as breaching patient confidentiality, offensive or both. Consent UK law holds integrity of the body in high regard. Treatment without a patient’s consent could be regarded as trespass to the person or assault (dependent upon the jurisdiction) even if the treatment was appropriate, carried out with appropriate skill and in the patient’s best interests. The law permits a presumption of capacity regarding adults, in the absence of contrary information. Adults with capacity to consent have a right to refuse any treatment even during treatment for which they have previously consented. Those providing care must be mindful of this and also of the requirements in their own jurisdiction when treating minors, infants or those unable to consent for themselves. Of particular relevance are the Mental Capacity Act 2005 (England, Wales and Northern Ireland); the Adults with Incapacity Act (Scotland) 2000 and the various pieces of legislation in place regarding children, which differs in different UK jurisdictions. Regulatory authorities and employers may require practitioners to obtain written consent for treatment or particular types of treatment. The General Dental Council has defined that within the UK written consent is required for sedation, general anaesthesia and for treatment carried out by students. The prudent practitioner should also ensure that complex irreversible forms of treatment also receive written consent. As a result of recent judgements, UK law is moving towards a doctrine of ‘informed consent’, but is still not as prescriptive as in certain states in the USA. The requirement in the UK is for patients to be given sufficient information, with regard to benefits, risks and possible complications that they can come to a rational decision as to whether they wish to have the treatment carried out. http://dentalebooks.com L a w, et h ics and q u ality dental care • 109 It is essential, therefore, that the patient’s clinical record indicates clearly that a process of informed and valid consent has been undertaken and that patients have been given sufficient information to come to a rational decision without any duress placed upon them. Contractual considerations Dental care and treatment can be carried out under different contractual regimes and it is incumbent upon the healthcare professional to ensure that the patient is fully aware of the nature of that contract. Healthcare professionals need to know the obligations that contracts place upon them. It is an implied term of any contract within the UK that the contract will be carried out with reasonable skill and care. Much dental treatment in the UK is carried out by practitioners in contract with a health authority providing care under a contract of employment (e.g. hospital and community employees), a contract under the general dental services or under a personal dental service type contract. Under such contracts, the contract holder will have contractual duties and be subject to Terms of Service as laid down by the health authority who are parties to those contracts. Failure to comply might result not only in a breach of contract claim but also in implementation of disciplinary measures by the health authority under the contractual terms. Although the patient and dentist may not have a direct contract between each other when treated under the National Health Service (NHS) general dental services or personal dental services, patients may still have contractual redress under third party rights in addition to claims in negligence or trespass. Third party funders, other than health authorities, may also prescribe contractual terms that require adherence by those carrying out patient care. Those receiving private dental care will be in direct contract with the other contracting party, generally the dentist responsible for the patient’s care. As well as the implication that any treatment will be of satisfactory quality, a patient may consider that remarks, comments or statements made by the practitioner form an express term of the contract (e.g. ‘you will be able to eat better,’ or ‘you will look fantastic’), facilitating a possible potential claim for breach of contract. Referring patients It is incumbent upon all practitioners to accept the limitations of their own skill and refer appropriately when required. As well as the act of referring, the practitioner should refer to an appropriate person and provide that person with sufficient information, in writing, for them to consider the urgency of that referral and whether it is appropriate for them to accept the referral. Particular attention must http://dentalebooks.com 110 • C L I N I C A L D E N T I S T RY therefore be paid to furnishing those to whom practitioners refer with adequate referral information in writing. If patients fail to attend for referral, for what might be considered a condition such as a tumour, etc.; robust protocols should be in place to contact the patient to ensure that they are fully informed and aware of the consequences of failing to attend such an appointment. It may be held out to be a misrepresentation for a dentist to profess that they have skills or abilities that their training and experience would not support when reviewed by peers. Dentists professing to have particular skills with regard to the provision of cosmetic treatments, particularly outside of the mouth or peri-oral region or outside of the practice of dentistry, may find themselves challenged by the regulatory authorities or the law in this regard. Carrying out treatment It is essential that treatment carried out is likely to be considered necessary when subjected to analysis by one’s peers and would be considered appropriate treatment of a contemporaneous standard and in accordance with current treatment rationales. Any treatment which might be construed as outside of ‘the norm’ or not following ‘guidelines’ will require justification both in the clinical record and with reference to research and the practitioner’s own review process. Similar caution and readily accessible justification must be apparent when treatment is carried out that could be construed as being of doubtful benefit to the patient. Given a practitioner’s ethical duty, the treatment must be con­ sidered appropriate and effective, particularly with regard to the patient’s presenting complaint and the need to deal expeditiously with any pain, suffering or potentiality for pain or suffering. A detailed appraisal of current acceptable operative techniques is readily available from up-to-date textbooks, journals, the Internet and similar sources. All treatment should only be carried out following a careful risk versus benefit analysis ensuring that the patient is fully informed of any potential risks, the likelihood of them occurring and the consequence that might result from any such untoward event. Those carrying out what might be considered strictly cosmetic procedures would be well advised to ensure of any imbalance in health benefit and risk in these cases. Record keeping – clinical records The value of full, clear and contemporaneous clinical records cannot be overstated. The making and retention of adequate contemporaneous records is a requirement of all dental care contracts. Clinical http://dentalebooks.com L a w, et h ics and q u ality dental care • 111 records also form the basis for establishing appropriate treatment planning, the completion of an adequate consenting process as well as the provision of adequate care in all circumstances. Given the significance that may subsequently be placed upon the clinical record if a patient complains or queries their treatment, a full charting of both the restorations and teeth present as well as those requiring treatment or observation is desirable. Periodontal assessment and appropriate charting is required. The record should also contain: • • • advice and warnings issued a record of failure by the patient to comply with advice notes of missed or broken appointments. A positive record regarding a patient’s presenting condition, even if unremarkable, shows that any complaints have been considered and addressed satisfactorily. An actual note in the clinical record supporting that a patient presented with no complaints is far more powerful than attempting to construe that no record of a complaint within the written note is indicative of no presenting problem. Whoever writes the record, the clinician with ultimate responsibility for the patient’s dental care will hold primary responsibility for any omissions or inadequacies. Addenda can be added to notes subsequently in light of ensuing events, but the record should never be altered or erased after the event. In the UK and Europe, given current consumer legislation, clinical records should be retained for at least 11 years after a patient last attended or after they reached the age of majority (18 in England, Wales and Northern Ireland, 16 in Scotland). An adequate clinical governance protocol, recorded in a clinical governance folder, governing precisely how each item of treatment, examination or review is carried out will reduce the amount of information that is required to be written on the patient’s record on each occasion. Records should be kept safely and access only given to those who are entitled to access them and who are bound by confidentiality agreements. Where records are held electronically, right of access to entries must be controlled securely and computerized records should be password protected. In the UK patients have rights to access their records and have the contents explained to them under the Data Protection Act 1998. Record keeping – other records Records must be kept to comply with requirements for Continuing Professional Development (CPD), clinical audit, peer review, etc. Records demonstrate compliance with Health and Safety, employment, radiation and fire legislation; they are also a statutory http://dentalebooks.com 112 • C L I N I C A L D E N T I S T RY requirement. Additionally, documentation will be required to be available when practices are inspected by contracting health authorities. The Freedom of Information Act further requires any dental practice providing NHS care in the UK to have a Publication Schedule available demonstrating what documentation is available from the practice for inspection. Equality and diversity Legislation in the United Kingdom prevents anyone discriminating against another because of age, religion, disability, gender, race or sexual orientation; it is vitally important that policies promoting equality and diversity are present in the practice, all practice staff should have signed that they have read the policies and consideration must be given to appropriate equality and diversity training. This is particularly important not only because this should be the ethos of any practice but also because it will be a requirement for a registrant challenged regarding equality and diversity to be able to demonstrate that these processes are in place. Standard 1.6 of the GDC’s Standards for the Dental Team adds gender reassignment, marriage and civil partnership, pregnancy and maternity to the litigation list as defined in the Equality Act 2010 – the nine ‘Protected Characteristics’: • • • • • • • • • Age Disability Gender reassignment Marriage and Civil Partnership Pregnancy and maternity Race Religion and belief Sex Sexual orientation http://www.equalityhumanrights.com/private-and-public-sectorguidance/guidance-all/protected-characteristics. Quality dental care Currently much emphasis is being placed on improving the quality of healthcare provision. This section describes some of the terms and definitions that have been introduced to describe quality issues. Whilst some of the terms are new, many of the concepts are not. Clinical governance Introduced in the 1998 White Paper A First Class Service – Quality in the New NHS. Many definitions have been suggested, including the one below. The value of clinical governance cannot be overstated, http://dentalebooks.com L a w, et h ics and q u ality dental care • 113 patients have a right to have a reasonable, consistent, safe standard of care provided by registrants and registrants should be able to demonstrate that not only do they have clinical governance tools in place but that they are reflective in their care and treatment: A framework through which NHS organizations are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which high standards of care will flourish or: Corporate responsibility for the delivery of quality healthcare. Clinical audit Clinical audit is the process of reviewing the delivery of health care to identify deficiencies so that they may be remedied. Clinical audit is an essential tool within a clinical governance regime and over a period should cover all aspects of clinical practice. Clinical audit requires the collection and interpretation of data in a manner that can be repeated, to show that any changes resultant from the audit have been effective when re-audit takes place. Establishing an audit cycle in this manner provides a tool to demonstrate effectiveness. Clinical audit is a cyclical process (Figure 5.5). It is conducted as follows: • • • • • look critically at a particular aspect of practice think about how what is being done compares to a defined standard measure what is being done against the standard implement change monitor progress by measuring again after change has been implemented. Clinical audit is a practice-based procedure that should be owned and participated in by all members of the dental team. Clinical audit assumes much greater importance and relevance when it can be seen to address and reduce or remove existing problems or difficulties within the practice. However, to be effective it must also be anonymous so that individuals do not feel threatened by results that demonstrate a need for change of their particular practice. In the absence of awareness of evident problems that require attention, patient questionnaires can provide useful ideas as to where to start a clinical audit. It is imperative to ensure that everyone within the practice is involved with the design of such questionnaires as they may receive criticism. Questionnaires must also be constructed in such a way that the collected data can readily be interpreted and the http://dentalebooks.com 114 • C L I N I C A L D E N T I S T RY Select topic Agree criteria and standards Monitor progress by repeating cycle Set data collection rules Agree and implement change Collect data Analyse and reflect on results Figure 5.5 Audit cycle. collection repeated in the future. It is also essential to ensure that patients are given the opportunity to give positive as well as negative feedback concerning the practice. Audits must be specific and not too wide-ranging; results should be shared with all concerned and contained within a readily accessible clinical audit file. They should not be shared with third parties as a management or disciplinary tool; they must primarily be educative for those taking part. Audit and research It is important to understand the difference between research and audit. • • Healthcare research is about extending the body of knowledge of best practice. Audit is about measuring whether best practice is being adopted. Peer review Peer review operates alongside clinical audit in general practice. Groups of dentists, usually about four to eight in number, meet in an http://dentalebooks.com L a w, et h ics and q u ality dental care • 115 atmosphere of complete confidentiality to review aspects of practice. It is not focused like an audit, but standards emerge as part of the discussion and it is less formal than audit. Peer review provides an effective mechanism for reviewing clinical practice and procedures amongst colleagues; however, it requires a high degree of trust and confidentiality to be established and a mutual respect of participants one for the other. Over a period of time all aspects of practice can be reviewed. Although a culture can be established by participants within the same practice, peer review is most effective when more than one practice participates in the process. Peer review must of necessity be non-threatening. It must be educational and should remain the property of the participants. Although individual participants or practices should be able to identify their own results within the collected, analysed data, the results should be anonymous to all others, particularly regarding the identity of individual patients or practitioners. Reflective learning It is a requirement that registrants maintain their skills and professional knowledge; in addition to undertaking regular appropriate CPD, it is also necessary for all registrants to have in place a programme of reflective learning to ensure that care and treatment are optimal. Reflective learning entails absorbing, not just acting upon, new information. Reflective learning requires time to think through things and the ramifications rather than accepting what one is advised at face value. Evidence-based dentistry Evidence-based dentistry (EBD) implies the use of techniques and procedures that have been shown by both research and audit to be clinically effective. The practice of evidence-based dentistry means integrating individual clinical expertise with the best available external clinical evidence from systematic research. Evidence comes from clinical trials, of which the randomized controlled trial (RCT) is viewed as the gold standard. Systematic reviews collate evidence (both published and unpublished) from different studies (of one or more experimental designs), summarize and grade the evidence available. Evidence is also disseminated in the form of clinical guidelines. http://dentalebooks.com 116 • C L I N I C A L D E N T I S T RY Clinical effectiveness Treatment which is ineffective or unnecessary is unlikely to be regarded by peers as satisfactory. Practitioners therefore should carry out audits and hold records to demonstrate effectiveness: covering, for example, items such as longevity of particular treatments. If a practitioner perceives that a particular treatment fails or has short longevity in their hands, yet allegedly gives good results for others, the reasons for this disparity should be ascertained and if possible addressed. Records of such reviews are frequently an effective rebuttal to any allegation of failure of a practitioner’s duty of care. Improving clinical performance Risk management and reporting of critical incidents and significant events are seen as important aspects of delivering quality care. Dental practitioners would be well advised to have in place, and to be able to demonstrate, procedures and protocols for dealing with risk, handling patient complaints, etc. Protocols The clinical record must be full, contemporaneous and accurate. However, if written protocols are developed within a practice and rigidly adhered to, the amount of detail in an individual patient record can be reduced. For example, if a dental examination always follows a standard protocol that defines all that is carried out, plus additionally the records confirm the necessary chartings, notes, etc., confirming compliance, the minutiae of the examination will not be required to be recorded each time. It is part of clinical governance that patients receive care of consistent quality. This requires the establishment of guidelines which are developed into written protocols. The protocols must also be regularly audited and if necessary reviewed and updated. A simple, but invaluable protocol should, for example, cover how a dental practice receives and deals with telephone calls. Many practitioners fail to realize the potential pitfalls resulting from a failure in communication when a patient contacts the surgery – these are easily prevented with a robust protocol that is rigidly followed. Patient and stakeholder involvement Taking into account the views of patients and their carers, as well as other stakeholders, is seen as an important aspect of quality health care; the GDC’s Standards for the Dental Team makes this a requirement with regard to patients. http://dentalebooks.com L a w, et h ics and q u ality dental care A B • 117 C Figure 5.6 Learning from significant events. Significant event analysis Sometimes referred to as critical incident analysis. It should become an established part of the practice procedure for all members of the dental team to analyse what went well, not just what went badly and then subsequently establish how successes may be repeated and how any mistakes or shortcomings may be prevented. A good record of such events should be retained. There is a wealth of information available on how to carry out significant event analysis (see Figure 5.6) – an actual dental analysis is also included: Complaints It is imperative that complaints are dealt with appropriately, expeditiously and sympathetically, ensuring that all matters relevant including the patient’s viewpoint are taken into account. Practices must have a written complaints policy which should be strictly followed; a rapid acknowledgement is essential. In the UK, acknowledgement of receipt of the complaint should always be made within 3 days, if possible, with a full response, or an explanation as to why a full response cannot be completed within the timeframe, a maximum of 20 days. How a complaint is dealt with is obviously a matter of personal preference dependent on the circumstances but it is always prudent to take advice. However, it is important that if the complaint is not dealt with entirely in writing, prior to any meeting there is a note made of all the items of concern and that the meeting has a structured agenda. After such a meeting the issues raised and their resolution should be recorded as a minute, distributed and verified as accurate by all parties. An apology does not need to be an admission http://dentalebooks.com 118 • C L I N I C A L D E N T I S T RY of liability; those complained about should never be afraid therefore to apologize if the facts deem this appropriate. Complaints should be recorded anonymously so that they can be used as an educative tool as part of the practice clinical governance programme. Effective dental care requires the confidence of the patient and the dental care team members one for the other. If such confidence has never been apparent or has been lost and is incapable of restoration, it should be suggested to the complainant that it is in their own best interests to seek their dental care elsewhere; such an action should be regarded as a pragmatic, appropriate remedy rather than a failure. Underperformance Practices must have a written underperformance policy that all members of the team endorse and follow. The causes of underperformance or inappropriate performance are myriad but it is important to separate dishonesty from underperformance and deal with each appropriately. Honesty is an ethical requirement of all dental professionals. They are in a position of trust and any attempt to address dishonesty or resolve it must ensure that a position of trust can be restored. Underperformance not associated with dishonesty should be dealt with sympathetically, ensuring that any danger to patients is immediately removed; it is also essential that the cause is identified, addressed and subsequently monitored for efficacy. Dealing with underperformance is difficult and harrowing for all involved but is an ethical obligation. The Dentist Help Support Trust (DHST), which can be contacted via the British Dental Association (BDA), does sterling work to assist dentists with alcohol, drug and health problems. Underperformance due to lack of ability or knowledge will require structured CPD or even retraining in some other discipline. Data collection and retention Governance in whatever sphere requires the collection and retention of accurate, relevant data in a usable format. Data must never be collected or computed in a fashion to give a specific desired result. Wherever possible, data should be anonymized, non-threatening and capable of being collected again in the future in a similar format. The data itself should be used as an educational tool to verify performance and address performance issues; its collection, interpretation and retention should not be regarded as a chore by team members but as an essential clinical tool and a robust authentification to counteract allegations regarding inappropriate performance. http://dentalebooks.com L a w, et h ics and q u ality dental care • 119 Conclusion Research has shown that most patients have high levels of confidence in those providing them with dental care. The dental profession can be proud of this but such good reputations are harder to achieve than to lose. In this litigious society we must strive to ensure that we have hard fact rather than anecdotal evidence to demonstrate that our patients’ faith in the dental profession and the care it provides for patients is justified. References General Dental Council, 2013. Standards for the Dental Team. General Dental Council, London. Available from:: <http://www.gdc-uk.org/Dentalprofessionals/ Standards/Pages/home.aspx> (accessed 6/11/15.). http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Practice management Introduction 121 Management skills 122 Financial management 124 Marketing 128 Employing staff and management 129 Information for patients 136 Data protection, information governance and Freedom of Information 137 General Dental Council regulations and obligations 138 6 Health and safety in the dental practice 140 Dental radiographs and regulations 147 Building design 151 Cross infection prevention 153 Time management 156 Dental Foundation Training, Dental Core Training and Dental Career Development Posts (DCDP) 158 Clinical governance, clinical audit, peer review and Continuing Professional Development 161 Introduction Dental practice is no different to any other business in that you need to organize the management of the business systems, team members, finances, policies and dental facilities to ensure that the main customers, or patients, receive the best service. Dental practices are subject to the same external pressures and changes that are taking place in the global marketplace, such as technological change, regulatory changes and increasing customer expectations. In order to succeed, any modern dental practice therefore needs to identify its place in the marketplace, and respond to changes with a management structure that embraces change with flexible protocols and systems that are continually reviewed, adapted and improved. However, the management of dental practices is often hampered by the fact that ownership and management are concentrated in one pair of hands – the dentist. This book highlights the many clinical skills required by clinicians to provide the endpoint of the business of dentistry: restorations, extractions, crowns, implants, etc. but, without the correct business and management framework for the service delivery, the business will ultimately fail. A successful dental business therefore needs to generate profit; a word often frowned upon in media comments regarding dentistry. However profit is paramount in order to run the practice effectively, http://dentalebooks.com 122 • C L I N I C A L D E N T I S T RY and in turn allowing re-investment in business development, thus benefiting customers, and providing success in achieving both personal and business goals. Analysis of some of the most successful and productive dental practices reveals the following characteristics, they: • • • • • • • • • • develop a vision of purpose, not just function. identify the behaviours required to anticipate their patients’ needs desire to instil the ‘wow’ factor in the minds of their patients desire to create an exceptional patient experience as well as an exceptional patient service understand that each point of contact with their patients provides an opportunity to either delight or disappoint manage processes rather than people use benchmarking to identify opportunities for improvement rely on patient satisfaction as the main measure of performance, overcoming the tendency to focus only on internal goals (at the patients’ expense) stimulate productivity by continually reviewing and developing their services develop and nurture their most valuable asset, i.e. their staff. Management skills Effective team management ensures a systematic and consistent approach to service provision which, if done well, increases both patient and staff satisfaction. Good business management requires planning: • • • • for service development to anticipate threats to maximize opportunities to enable the business to survive in a competitive marketplace. Communication Dental practitioners are now more aware than ever of the need to communicate effectively with patients and others to avoid complaints and potential litigation, however the essential skill of communicating with the team is often overlooked. Communication should be a two-way process. Practice owners should listen to their staff as they often have insightful knowledge of the dental business from a different perspective. Staff meetings • An excellent opportunity to communicate providing the structure for agreeing policy or procedural change. http://dentalebooks.com P ractice m ana g e m ent • • • • • 123 An agenda is important and should include regular items including business performance, systems issues, complaints and significant events, marketing opportunities. Meetings can be held whenever convenient for the practice (consideration should be given to closing normal business to hold a meeting) but need to be regular. Any meeting should be considered as a training session and used in that capacity – they should be informative, positive and supportive, not an opportunity to moan. Truthful and honest analysis of what is working and what is not working is desirable. Minutes are vital to reinforce decisions, measure progress and disseminate information to absent team members. Delegation Practice owners should identify and understand their limitations – no one person can do everything. By employing people you trust, ensuring they have the necessary skills and a complete understanding of what is required, you should be able to delegate sufficiently to spread the burden and allow more time to focus your attention on the important task of developing and growing the business. Some tasks can be appropriately delegated to external agencies such as: • • • • • Human Resource (HR) advice and guidance Fire, and Health and Safety, Assessments Payroll Accounts Advertising, marketing and social media communications. Teamwork Fostering a supportive team approach can be difficult. People may feel defensive and resistant to change if there is insufficient trust in management. Successful leadership results from encouraging staff to maximize their potential as individuals and in a team, working towards clear objectives. Roles need to be defined but skills should be shared wherever possible to eliminate a skills gap if a member of staff is temporarily absent, for example. The following principles could be adopted: • • • • Clearly define roles – provide clear, concise job descriptions Provide written systems of work – everyone knows what needs to be done Use an Organizational chart – provides a clear reporting structure Maximize information flow within the practice – upwards, downwards and sideways http://dentalebooks.com 124 • • C L I N I C A L D E N T I S T RY Set goals – targets, responsibilities, measuring success, talking about success, rewards (bonus system, team days out, increased individual responsibility, a simple thank you!). Staff training Your team is your most valuable asset; therefore investment in team training is important so long as it is focused and relevant. • • • • • • New staff need to be trained in practice policies and procedures, but also in practice ethos so they are in tune with the practice goals. It is important not to rush this or assume that this training is complete simply because time has passed – you will need to check their understanding and competency. To comply with GDC requirements, dentists and DCPs must carry out at least minimum levels of CPD and provide evidence. Training can be provided in-house or the practice owner should allow reasonable time for external training. Although it is the individual’s responsibility to ensure CPD levels are achieved in order to maintain registration, the practice should help by tracking progress with training records. A regularly reviewed practice training plan supporting the practice goals should identify existing skills and knowledge gaps which helps target future training. (Do not waste money on training nurses to obtain skills which you do not intend using in the business). Pay Money is not the only motivator (status is important to many people), but it is (or should be) an important one and therefore any remuneration system should be fair and equitable. Rates of pay are influenced by: • • • What the practice can afford The market going rate for skill level The availability of suitably qualified staff for that role. Dental associates are often incentivized by performance-related pay. This can be considered for other team members too, but managers must be aware that bonus payments can cause conflicts and divisions in a team if not applied considerately. Financial management Although book-keeping and accountancy skills can be outsourced, it is important that the practice owner has a good awareness of the http://dentalebooks.com P ractice m ana g e m ent • 125 current (day to day) financial health of the business so that timely adjustments can be made to maintain and improve profitability. Investigation of fluctuations in business performance can highlight areas where systems and protocols are breaking down and customer service is suffering. Dentists in practice should be familiar with: Cost analysis • Overheads (fixed) which do not relate to the output of the practice but relate to practice environment such as rent/ mortgage payments, fuel costs, some staff costs, leasing and loan costs • Direct (variable) occur as a direct proportion of turnover (or fee income) such as laboratory fees, dental materials, fees paid to associates • Break-even point is where the level of income meets the total running costs (overheads + direct costs) • Income may be fixed or variable – fixed income from private capitation schemes such as Denplan, premises rental, NHS fees (less patient payments). Variable income from private fee per item work. Financial ratios A practice with a large turnover may produce a low profit if the running costs are high. Analysis of income and profit does not necessarily provide useful data on which to determine the financial health of the business. Ratios provide a more meaningful method of analysis which can be benchmarked against national standards of performance: • • • • Gearing – ratio of value of assets to value of liabilities, reflects the level of financial risk. A high level of debt is risky, but at a moderate level, long-term liabilities may represent prudent, strategic borrowing at lower interest rates. Current ratio – a measure of liquidity – how easily could the practice obtain cash to pay off debts. Return on investment – the financial benefit gained from the investment made. For example, what income can be expected from the purchase of a cone beam scanner at a purchase price of £50k? Does the projected income justify the purchase of expensive equipment? Return on capital employed – the financial benefit of obtain­ ing a practice as a percentage of the purchasing capital (funds). Cost control and budgets. Cost control seeks to restrict expenditure within the limits of budgets and feasible income. http://dentalebooks.com 126 • • • C L I N I C A L D E N T I S T RY Direct methods include negotiating better purchase prices for goods/services, reducing waste. Indirect methods – enhancing business performance and re­­ ducing the hourly rate of overheads such as maximizing the use of resources (opening longer hours?), more efficient systems of work, identifying new business opportunities. Budgets. Set targets to be achieved and allow comparison with actual results. Budgets are the financial expression of any business plan. Cost control is not just about reducing expenditure, rather it should be employed to analyse what has happened against what was predicted and enable further wise investment which will benefit the business performance in future. Fee setting The practice policy on fees should be clear to both staff and patients. Written guidelines should be made available to patients at their regular visits and referred to on the practice website, information leaflets, etc. Consideration should be given to: • • • • • • • Fee amounts – fixed or variable. How much discretion is given to associates to amend prices? What proportion of fee does patient pay for at each visit – total cost of whole treatment or for work carried out to date? Fees for missed appointments Deposits for booking appointments Payment for laboratory work prior to fitting Methods of payment accepted (additional fees for credit card payments?) Reviewing fees – will there be an annual review? How will patients be notified of any changes? Cash flow Many businesses have ceased trading as a result of insufficient cash funds which enable the business to operate day to day. ‘Cash is King’ is a guiding principle of paramount importance. A negative cash flow occurs when the practice has to pay out more than it receives in fees and can result from reduced workload (a holiday season?), high level of bad debts, poor business performance, lack of cost control, heavy borrowing costs. Analysis of business performance against budgets may reveal a short-term issue which could be alleviated with a temporary increase in bank funding (overdraft) or it may be an indication that the business is not viable in the longer term. http://dentalebooks.com P ractice m ana g e m ent • 127 Borrowing and repayment methods Borrowing for capital purchases, including the purchase of dental practices, is currently subject to more rigorous procedures than has historically been the case for dental professionals. Business plans must demonstrate a high level of financial resilience and demonstrate the affordability of loan repayments in the face of prospective interest rate increases. Capital funding is available from a number of sources however, and not only from the usual high street banks. Consider all the options (including government funding, asset finance, peer to peer lending, crowd funding) and negotiate the right deal – do not accept the first offer of funding without making comparisons. Repayment methods can vary (capital + interest or interest only) and the choice made can have a major impact on cash flow. An awareness of economic influences National and local economic confidence can affect the income of both NHS and private practices – business planning should include an element of risk assessment on the potential impact of economic downturn. Interest rate increases may have a disastrous impact on the cash flow of a highly-geared practice (with heavy borrowing). Financial record keeping Clear, accurate records are essential for • • • • • Maintaining accounting and book-keeping purposes (and assessing tax liabilities) Recording patient payments Providing statistics for business reports Monitoring cash flow Observing trends. The role of financial advisers Including: • • • • • Bank managers Independent financial advisers Accountants Management consultants Lawyers Establish: • • • Their area of expertise Their knowledge of dental industry References from other clients http://dentalebooks.com 128 • • • C L I N I C A L D E N T I S T RY Fees chargeable Are they independent or tied to products. Monitoring performance (KPIs) Measuring how well the practice is performing at regular intervals helps you keep control and make adjustments to improve performance while there is still time to act. Key performance Indicators (KPIs) can be anything you wish to measure such as: • • • • • • • Actual hourly rates earned Monthly gross income UDAs (Units of Dental Activity) per day Number of active (under treatment) patients Number of new patients monthly and referral sources Telephone or other enquiries converted to new patient bookings Patient feedback (satisfaction surveys). Interest free/Finance options Practices extending finance options to patients are governed by the Consumer Credit Act 1974 (reformed 2006) and must obtain a valid licence. However, a licence is not required if fewer than four instalments are payable in under 12 months. Marketing A general definition of marketing is understood by many to be ‘Putting the right product, in the right place, at the right price, at the right time’ but although this sounds easy, balancing these elements requires some preparation, research, training, skill and evaluation. The 4Ps of marketing were expressed by E. J. McCarthy in 1960 as Product (or service), Place, Price and Promotion and a successful marketing strategy asks questions such as: Product • What does the customer want from the product/service? • What needs does it satisfy? • How will the customers experience it? • What will it be called? • How will it be branded? • How is it different from what your competitors are offering? Place • Where do customers look for your product/service? • What do your competitors do? And how can you learn from that or differentiate? http://dentalebooks.com P ractice m ana g e m ent • 129 Price • What is the value of the product/service to the customer? • What are the established price points for the product/service in the local area? • Is the customer price sensitive? Decreased price may mean more market share or increased price, more profit margin. Promotion Where and when can you get your message across to your target market? • What method is best employed to reach your target market? • When is the best time to promote your product? • How do your competitors promote their services? Does this influence the way you do it? • A successful dental practice is able to attract a patient base that wants the services being offered, appreciates the way those services are delivered, is prepared to pay a commercial price for those services and, ideally, becomes a ‘fan’ of the practice, engaged with the practice ethos and spreading a positive image of the practice and services through their own personal contacts. The first step in any marketing campaign is therefore to identify what the purpose and ethos of the practice are so that these characteristics can be used to market your ‘unique selling point’ which makes your practice different from your competitors. An analysis of Strengths, Weaknesses, Opportunities and Threats (SWOT) is useful in identifying what features the practice can promote over its competitors and how it needs to develop further to maintain an advantage. Mission and vision statements help to clarify and communicate the purpose of the practice to both the team and patients and aid in aligning everyone to the practice objectives. Employing staff and management The dental team members should be the greatest asset of the practice – their attitudes, skills, commitment and communication with patients can make the difference between being a successful, thriving practice or being a practice which fails to please and is restricted in its development. Recruitment It is very difficult to ensure that any selection process will result in the recruitment of an ‘ideal’ team member with the required skill set and personal attributes, but a methodical, objective approach is more http://dentalebooks.com 130 • C L I N I C A L D E N T I S T RY likely to succeed than a less formalized method, and is also best practice in avoiding discrimination claims. Before advertising a vacancy, consider: • • • Is a new member of staff at the previous level required? It could be an opportunity to reorganize team structure. Do you just want a new for old swap or extended responsibilities which may be beneficial for the practice? Why did the previous member of staff leave? (an exit interview is useful) Then prepare a job description – including lines of management and responsibility and a comprehensive list of tasks. Make sure there is a section ‘to include any such duties as may be necessary for the efficient operation of the practice’ to allow flexibility. Person specification Describes the qualifications, experience, skills and abilities that are essential or desirable (not vital) for the job and is useful for assessing which candidates to shortlist and interview. You may not find someone that meets all the requirements but you should aim to appoint someone who satisfies all your essential requirements and some of your desirable ones. Consider: • • • • • Qualifications and training Experience Skills and abilities Knowledge Personal attributes. Pay structure Be prepared with a clear pay structure for prospective employees. You should know what the practice can afford, having considered employers’ tax costs, and what the local going rate is for the vacancy advertised. Advertising Consider the most appropriate medium for advertising the vacancy, for example local/national press, professional journals, social media, internet, internal/external notices, job centre. Remember equality and diversity issues. The aim is to attract a large pool of applicants from which to shortlist your interview candidates. Any advertisement should be written with AIDA in mind: • • Attention Information/interest http://dentalebooks.com P ractice m ana g e m ent • • • 131 Desire Action. You may choose to use a recruitment agency, or you may be contacted by agencies following publication of your advert. If you decide to use their services be very sure that you have read the small print of the contractual terms before entering into an agreement; misunderstandings can prove costly! Screening applications You should specify how you wish to receive applications – CV and covering letter or application form. Both have their merits – failure to comply with application instructions may be one of your criteria for eliminating candidates! Objective screening is possible by comparing applications against your job description and person specification. Keep written records of the selection process which align with the selection criteria (your records may be required by an employment tribunal if any candidate feels they have been rejected for illegitimate reasons). The Equality and Human Rights Commission (EHRC) recommends more than one person to conduct the screening process to improve objectivity. A numerical weighting and scoring system can be used – candidates achieving a pre-determined score will be asked for interview. Applicants who have not made the short-list should be notified. This is common courtesy and presents the practice in a good light. You may want those candidates to apply again in future. The interview Successful interviewing is a skill which many find difficult and which can really only be perfected through experience. Preparation is key – interviewers should have read the information about the candidates and prepared a list of standard questions. At least two people should interview. There should be agreement reached beforehand on how the interview will be structured, and who will lead the sections of the interview including: • • • Opening statements – welcome and introductions Body of the interview – obtaining new information about the candidate in addition to that provided in the application (using exploring open questions frequently starting with Who? What? Why?) Asking questions that relate to characteristics described under discrimination law is likely to be illegal (sex, disability, age, race, religion or belief, pregnancy and maternity, marriage and civil partnership, gender reassignment and sexual orientation) http://dentalebooks.com 132 • • C L I N I C A L D E N T I S T RY including questions relating to a woman’s marital status or childcare arrangements You are able, however, to ask a candidate if they have any responsibilities that may interfere with their attendance at work. Remember that: • • • The interview is a two-way process – you are being assessed by the candidate as a potential employer The candidate should talk far more than you do – consider 20% interviewer, 80% candidate – no matter how proud you are of your practice or a recent treatment triumph! Records of an interview can help avoid legal issues later on. Closing remarks – summarizing the views and opinions expressed by the candidate during the interview. Information about how the candidate will be informed of the outcome. Allow sufficient time between interviews for discussion and making summary notes. You may wish to include tests to assess the candidates’ skills such as: • • • • Personality tests Aptitude tests Intelligence tests Role competency. Job offer Once a decision has been made, the job should be offered by phone and then if accepted followed up by letter confirming the details of the post, and ideally including the employment contract. It is sensible to give deadlines. Clarify the start date and inform other candidates of the outcome, being prepared to give feedback on their interview performance and the reasons they were unsuccessful. Pre-employment checks must include: • • • • • • Evidence of the right to work in the UK (Immigration, Asylum and Nationality Act 2006). Refer to Home Office Border’s Agency guidance Registration with the GDC if relevant Health screening and immunization records Working with children and vulnerable adults – enhanced dis­ closure checks for staff working with patients. Disclosure and Barring Service (DBS-previously CRB) in England and Wales, Disclosure Scotland and Access Northern Ireland undertake criminal record and barred list checks. References – at least two written references, one from a previous employer Relevant qualifications – evidence seen and checked http://dentalebooks.com P ractice m ana g e m ent • • • 133 Explanations of any gaps in employment history P45 required from previous employment to enable accurate tax deduction. Employment contract A written statement of terms and conditions must be given to a new employee within 2 months of the start of employment. A contract is held to exist when an employee accepts an employer’s terms and conditions of employment by starting work. The contract is binding for both employer and employee, imposing rights and obligations on both parties which may be expressed or implied, including the duty of employees to: • • • • Provide a personal service and be ready and willing to work Exercise reasonable skill and care Not to disclose confidential information (this obviously includes patient information) Obey lawful instruction. A probationary period is always prudent for induction and assessment of any new employee and can be extended, with notice, until you are satisfied the arrangement is working well for both parties. Normal disciplinary rules and procedures must be followed if you decide to terminate the employment during this period. The written statement of terms and conditions should include the: • • • • • • • Date of commencement of employment Job title or a brief description of duties Place of work or, if the employee is required or allowed to work in more than one location, an indication of this and of the employer’s address Scale or rate of remuneration or the method of calculating remuneration – itemized pay statement must be given to employee. Check compliance with current National Minimum Wage. Intervals at which remuneration is paid Hours of work – basic hours, the days they are expected to work, their starting and finishing time, and their allowances for lunch, tea and coffee breaks. Hours may be flexible – this should be shown in the contract. Working time regulations dictate maximum working hours and rest breaks. Employers need to keep records of working hours for all staff to show compliance with weekly working time limits. If your pay records show the hours worked each week this may suffice. Holiday entitlement, including public holidays, and holiday pay. You may need to consider religious holidays or working hours. The legal minimum entitlement to paid holiday is currently 5.6 working weeks per year, which is intended to provide a basic http://dentalebooks.com 134 • • • • • • • • C L I N I C A L D E N T I S T RY entitlement of four weeks’ leave plus paid leave for the bank holidays. For employees who work five days a week, this means 28 days. The employer is free to increase this amount. There is no qualifying period for leave; the entitlement commences on the first day of employment. Requests for annual leave can be rejected with a good reason. Holiday rates of pay are the same as the employee’s normal rates. Part-time workers are entitled to holiday pay on a pro-rata basis. Sickness or injury absence procedure and sick pay – to enable the effective management of potentially disruptive absence, all employers, regardless of their size, should have a sickness and injury absence policy to ensure that both employer and employee are aware of their rights and obligations. Pensions and pension schemes – currently, there must be access to a Stakeholder Pension Scheme if no occupational pension scheme is in place. Legislation is now in place to ensure that all employers provide workers with a work place pension scheme for employees over 22 years old through automatic enrolment. Notice period – what length of notice the employee is required to give and entitled to receive. Grievance procedure – Contracts must refer to formal grievance procedures which set the framework for dealing with employees’ concerns. You should make staff aware of the procedure and follow it routinely to ensure that everyone is treated in a fair and consistent way. Disciplinary rules and procedure – to provide a fair and consistent method of dealing with serious conduct or performance problems. A written procedure is essential – employees should know exactly what is expected of them and what will happen if they break the rules, the procedures that will be followed and the action that might be taken. Employees with 2 or more years’ continuous service (1 year for those employed before April 2012 and for employees in Northern Ireland) can claim unfair dismissal. Claims for breach of contract can be made if disciplinary rules are not followed for employees who have been employed for less than 2 years or if discrimination is claimed. Details of any collective agreements which directly affect the terms and conditions of employment. For non-permanent employment, the period for which employment is expected to continue or, if it is a fixed term, the date on which it will end. Maternity and Parental Rights – give pregnant women significant benefits and protection in employment, including the right to maternity leave. These rights apply to all employees including men. http://dentalebooks.com P ractice m ana g e m ent • 135 Staff Appraisals are required at least annually (try to hold annual appraisal meetings with 6-monthly review meetings) to: • • • • • • • assess an employee’s performance and potential. provide both the manager and worker with the opportunity to agree objectives, identify training needs and consider future career development. focus on the employee without the interruptions of daily work. motivate staff; they allow employees to reveal what they have achieved, to discuss what they want to achieve and whether any resources to aid further achievement are required. uncover problems early and help to avoid potential future grievances or disciplinary meetings. provide documentary evidence of your employees’ continuing performance and encourage the views of you and your employees to be discussed and recorded. Set realistic targets. Targets should be SMART – Specific, Measurable, Agreed, Realistic and Time-bound. make a record of what was discussed and agreed and ask the employee for their comments. Employee should have a copy of the notes. Ending employment Employees can choose when they wish to resign from their post but you can require them to give you written notice of their resignation. The minimum statutory notice that an employee must give to an employer after 1 month’s service is 1 week. You can require employees to give more notice, as long as it is reasonable. One month’s notice is common, although 3 months’ notice for more senior employees may be appropriate. Employers must comply with the laws on unfair dismissal and discrimination if they want to terminate an employee’s contract of employment. It is wise to seek expert help on this before you take any disciplinary action to make sure that you are following procedure correctly. You must always seek independent legal advice before issuing notice to any employee. An employee who is dismissed with little or no notice may have a claim for wrongful dismissal. Minimum legal notice entitlement • One week if employed more than 1 week, less than 2 years. • More than 2 years employment – 1 week for each year of employment up to maximum of 12 weeks. Exit interviews. give you the opportunity to understand the reasons for the employee’s departure and to get more objective feedback on their experience of your practice. http://dentalebooks.com 136 • C L I N I C A L D E N T I S T RY Post-employment restrictions All GDC-registered dental professionals are now able to set up and own a dental practice, so it is possible for any registrant leaving your employment to set up a competing practice. The law allows you to restrict former employees from setting up in practice (but not from working at another practice). Any restriction must be in writing (in the Associate’s Agreement or contract of employment), must be signed by the employee or associate and must be reasonable in terms of distance and duration. Information for patients Current NHS Regulations stipulate that a practice information leaflet is made available for patients and must be reviewed annually. Private practices should also use this as a framework for providing information about the practice which may be made available to patients in electronic form. As a minimum, the required information includes: • Name of the NHS contract provider, or in corporate practices, the names of directors • The full name of everyone providing dental services under the contract and their professional qualification • Describe any teaching or training which might be carried out by the contractor • Address(es) of practice premises • Practice contact details • How patients can access services and what services are available • Patients’ right to request to see a particular practitioner • Disabled access arrangements • Practice hours of opening • Arrangements for out of hours care • Contact details for NHS Direct • Complaints Procedure • The rights and responsibilities of the patient (describe the standards of behaviour expected: advanced notification of nonattendance, treating staff with courtesy, prompt payment, and the standards they can expect from you) • How you will deal with violent or abusive patients • Access to patient information and patients’ rights about the disclosure of information • In England, contact details for NHS England Local Area Team. Further information to include, if relevant, might include: • Practice philosophy • Facilities and specialist services http://dentalebooks.com P ractice m ana g e m ent • • • • 137 Further information about the team and any special interests (take care to avoid any misleading claims). Payment policy – deposits, charges for non-attendance, credit facilities, methods of payment accepted Map showing location of practice. The information presented should be clear, concise and nontechnical, with some thought given to layout and design. Production can certainly be done in-house using a desktop package if skills are available but it is a fiddly and time-consuming task which you may prefer to out-source. Be careful not to spend too much money on a glossy leaflet which needs regular updating as personnel and contact details change. A well-designed leaflet is a useful tool for attracting new patients; identification of your target market should influence the design. As with any other form of advertising, GDC regulations prohibit: • • • Describing a dentist with specialist expertise unless they are on the specialist register Advertising other services and goods Being other than legal, decent, honest and truthful. Data protection, information governance and Freedom of Information Every patient within the dental practice should be confident that their personal and clinical records are securely safeguarded and shared appropriately only when it is in their interest. Each member of the dental team has a legal obligation to protect patient information. Patient data is information which: • • is stored or is intended to be stored on a computer is stored on paper or other media, which allows access to information about individuals. Additionally: • • Practices storing information on a computer must notify the Information Commissioner The commissioner does not need to be notified if non-computerized records are kept, however the principles of the Data Protection Act must be adhered to. The Data Protection Act (1998) requires that patient data: • • • • must be obtained honestly and fairly and only used for a specific and lawful purpose should be protected and held securely is relevant and kept up to date is accessible to patients upon request http://dentalebooks.com 138 • • C L I N I C A L D E N T I S T RY should not be excessive, and kept for only as long as required (records should be kept for 11 years or until the patient is 25 years old). Further considerations • • • • • • All team members must be aware of the need for strict patient confidentiality Do not discuss patients within the hearing of other people All computers in the dental practice must have a screen lock password and a timed screen saver facility to keep information secure from public viewing. USB sticks, etc. should be password-protected Data entries should be logged with individual passwords for each team member Adequately secure on-site and off-site data back-up storage facilities must be in place. Freedom of Information Act (FOIA) Patients have the rights to obtain information about themselves held on computers, and in paper files under the Data Protection Act (DPA). The Freedom of Information Act extends these rights to allow access to all types of information, both personal and non-personal, held by a public authority (including dental professionals). Practices are required to adopt and maintain a publication scheme, detailing the different types of information held and if there is a charge (under FOIA request) for its release. A request for information under the FOIA can, however, be denied where: • • • The request is repeated and/or vexatious The cost of complying exceeds the maximum applicable fee (£450) The information requested is covered by any of the 23 exemptions of the FOIA. Information requests should be responded to within 20 days, unless a fees notice is issued and the 20 days starts from the receipt of the requested fee. Should the fee not be received within 3 months, there is no obligation to comply with the FOIA request. General Dental Council regulations and obligations (see Chapter 4) The internet and social media guidelines In the eyes of the GDC, every dental professional is never ‘off duty’, and they can have their name erased from the register if they http://dentalebooks.com P ractice m ana g e m ent • 139 have been convicted of a criminal offence or it has been found that their fitness to practise has been impaired; this has an impact on each registrant’s personal life, internet and social media implications. No information or comments about patients should ever be posted on social network or blogging sites such as Facebook, Twitter, YouTube, Flickr, Pinterest, Instagram, etc. Patient information should not be sent by Email. Think carefully before accepting ‘friend’ requests from patients. In addition, GDC registrants should not post personal information, pictures or videos which could in any way bring the profession into disrepute. All dental practices should have an internet and social media policy, which must be adhered to by all team members. Fitness to practise proceedings (see Chapter 5) Where the GDC obtains information that questions a registrant’s fitness to practice, it can investigate and impose constraints on an individual’s registration. Impairment of fitness to practise may be due to: • • • Personal or professional misconduct, including cautions or convictions within or outside the UK Poor and deficient professional performance Adverse health Fitness to practise allegations follow a set procedure: • • • Caseworker – assesses if the allegations regarding a registrants FTP warrant further investigation. If so, then the case is passed on to the Investigating Committee. The registrant is invited to respond to the allegations. Investigating Committee meets in private and assesses all information regarding allegations and the registrant’s response, there are three possible outcomes: 1. No further action – case dropped 2. Issue advice to the registrant or issue a private or public warning (highlighted on the GDC register) 3. Refer to the Practice Committee. Practice Committee composed of: 1. Professional Performance Committee regarding deficient performance 2. Health Committee regarding physical and/or mental health issues 3. Professional Conduct Committee dealing with criminal convictions and gross misconduct. http://dentalebooks.com 140 • C L I N I C A L D E N T I S T RY If the PC decides that a registrant’s fitness to practise has been impaired it can impose the following sanctions: • • • • Removal from the GDC register for 5 years Suspension from the register for up to 12 months Allow a registrant to practise but with conditions for up to 3 years Issue a reprimand. If you do find yourself in trouble, as always, it is important that you contact your Dental Defence Organization as soon as possible to seek out specialist advice. Health and safety in the dental practice Dental practices need to properly manage all aspects of health and safety on their property and are governed by the Health and Safety at Work Act (1974), since the health of patients and staff may be compromised by failing to put adequate procedures in place. The practice owner has a duty of care to ensure, as far as reasonably practical, the health, safety and welfare of employees, members of the public and self-employed contractors who may be on the premises (including car parks and other external spaces). The Health and Safety Executive (HSE) exist to provide advice and guidance and also enforce the regulations by issuing improvement or prohibition notices, by seizing or destroying potentially harmful substances or items and/or prosecuting anyone in contravention of a legal requirement. Additionally, the CQC (Care Quality Commission) standards expect you to look after the welfare of patients as well as providing a safe working environment for staff. This means continually assessing the safety of the premises and equipment, as well as training staff in the basics of safety and risk management. Intuitive risk assessment, habitual incident reporting and analysis which deliver insight are all central to good health and safety. Definitions Risk The likelihood that anyone will be harmed by a hazard. Hazard Anything with the potential to cause harm. Risk assessment A critical and systematic assessment of what may cause harm within the workplace, e.g. chemicals, work activities, equipment. Following the systematic risk assessment the dental practice should: Assess the risk of the hazard: is it low, medium or high risk? Consider what could reasonably be done to minimize or prevent the likelihood of harm occurring. Review existing precautions – do they need modifying? Review staff training – is it adequate or is more needed? Document and record all findings and implementations. Arrange periodic reviews of risk assessments. • • • • • • http://dentalebooks.com P ractice m ana g e m ent • 141 Basic requirements of the Health and Safety at Work Act: • • • The approved poster ‘Health and Safety Law – what you should know’, should be displayed in the practice or available as a leaflet for all employees. The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR) require employers to notify the HSE of major accidents (including death) and dangerous occurrences. All incidents should be reported immediately to the HSE online, by phone, or by post http://www.hse.gov. uk/riddor/report.htm. and should include any work-related accident that causes an absence from work of a period longer than 7 days. Full details of the incident should also be recorded in the practice. There is a requirement to report some specific injuries, but other injuries are not excluded, as well as work-related diseases such as carpal tunnel syndrome. Further information on this can be found on the HSE website. Adverse incidents (breakages, malfunctions affecting patient care) involving medical devices should be reported to the Medicines and Healthcare products Regulatory Agency (MHRA). The practice owner is also required to: • • • • • • Provide a written health and safety policy (> 5 employees), which is brought to the attention of all employees and each employee should be given a copy. Associates and self-employed hygienists and therapists must be included and comply with the policy. Provide and maintain safe equipment, appliances and systems of work Ensure that dangerous or potentially harmful substances or articles are handled and stored safely Maintain the place of work, including the means of entrance and exit, in a safe condition Provide a working environment for employees that is safe, without risks to health and with adequate facilities and arrangements for their welfare at work Provide necessary instruction, training and supervision to ensure health and safety. Hazardous substances The Control of Substances Hazardous to Health (COSHH) regulations (2002) require that employers identify all such substances within the dental premises (including microbes and vapours), review their use and storage, to minimize any risk to health. A COSHH assessment should: • • Identify any hazardous substances and list them Identify who may be at risk from each item http://dentalebooks.com 142 • • • • • • • • C L I N I C A L D E N T I S T RY Review the method and frequency of use of the substance, its storage and disposal Identify precautions needed, e.g. ventilation, the availability and use of Personal Protective Equipment (PPE) Ensure measures to control exposures are implemented and that safety procedures are invariably followed Assess the need for health and/or environmental monitoring Provide a written plan to manage accidents/emergencies involving each hazardous substance identified Ensure all members of the team are properly supervised and trained Document and record the COSHH assessment. Mercury safety Mercury is still one of the most widely used and most hazardous substances in dentistry and all team members must be aware of the potential hazards. The following should be in place: • • • • • • Pre-dispensed encapsulated amalgam should be used Amalgamators should have a safety cover and be routinely checked A mercury spillage kit should be available and staff trained in its use All waste amalgam and used amalgam capsules should be securely stored in a container with a mercury suppressant Amalgam waste should be disposed of by an external, licensed hazardous waste contractor Amalgam separators must be fitted to dental chairs. Latex allergies Latex allergies are increasingly common, affecting ~1% of the population and 10% of the health care profession and latex-free gloves should be used accordingly. Nitrous oxide Suitable ventilation and scavenging must be ensured where this is used. Disposal of dental waste Dentists are responsible under the Environmental Protection Act 1990 for the segregation of waste, to store it safely in an appropriate container and to arrange for its safe disposal. All waste in a dental practice must be separated into hazardous and non-hazardous waste. http://dentalebooks.com P ractice m ana g e m ent • 143 Hazardous waste includes: • • • • • Any waste contaminated with body fluids Personal Protective Equipment (PPE) Needles Amalgam X-ray solutions. The practice should ensure that: • • • • • • • A nominated person should be given overall responsibility for the waste disposal procedure There is a written policy for the separation and disposal of hazardous waste Orange bags are used for the disposal of hazardous waste Black bags contain only municipal waste All hazardous waste is stored in a safe place and cannot be accessed by any member of the public or wildlife When hazardous waste (including clinical waste) changes hands, a consignment note must be completed and a copy retained. It is the responsibility of the dental practice to check that only authorized persons collect the waste (check licences and registration certificates) and that transfer/consignment notes are correctly completed and signed Copies of transfer notes must be kept for 2 years and consignment notes for 3 years. Quarterly returns (from consignee to dental practice) are also required for waste requiring a consignment note. Cross Infection Control See section 12. RIDDOR (2013) Reporting of Injuries, Diseases, and Dangerous Diseases All employers, self-employed and people in control of a dental practice have a legal responsibility to report serious workplace accidents, occupational diseases and specified dangerous occurrences. The following must be reported: • • • Deaths and serious injuries caused by workplace accidents – injuries resulting in hospitalization for more than 24 hours or rendering the individual unable to work for more than 3 days. Occupational diseases including carpal tunnel syndrome, cramp of the hand or occupational dermatitis, hand arm vibration syndrome, occupational asthma, tendonitis or tenosynovitis. Dangerous occurrences such as incidents involving lifting equipment, pressurized systems (autoclaves, compressors), electrical http://dentalebooks.com 144 • • C L I N I C A L D E N T I S T RY incidents causing explosion or fire, explosions, biological agents, X-ray machines and radiography. Gas incidents including portable gas units and mains supply involving an accidental leakage of gas, an incomplete combustion of gas or the inadequate removal of products of the combustion of gas. All incidents should be reported immediately to the HSE by phone, by post or online at http://www.hse.gov.uk/riddor/report.htm. Full details of the incident should also be recorded in the practice. Medical devices directive All dental prostheses and orthodontic appliances are now regarded as custom-made devices requiring a written prescription from a dentist. All prescriptions should be documented and stored in the patients’ records. Dental laboratories are required to register with the Medical Devices Agency. Water supply and dental unit water lines A written risk assessment including periodic testing of water lines for Legionella should be in place. The mains water supply to the practice should have an in-built air gap which protects against the backwash of contaminated water from the dental unit (spittoon, handpieces, wet line suction). Many dental chairs now incorporate an in-built air gap or are supplied with a clean bottled water system. X-rays, CBCT machines and radiography See Chapter 8. Fire safety The practice owner is responsible for carrying out a Fire Safety Assessment or can delegate this responsibility to another competent person. The Regulatory Reform (Fire Safety) Order 2005 describes the responsible person’s duties as: • • • • • the elimination or reduction of risks from dangerous substances – flammable substances, training in their use fire fighting and fire detection – extinguishers and fire alarms emergency routes and exits – access and lighting maintenance of equipment, facilities and devices provided – regular testing and examination provision of information to employers of contract staff or workers. http://dentalebooks.com P ractice m ana g e m ent • 145 Everyone should be able to leave the building quickly and safely in the event of fire, including anyone with a physical disability. Fire precautions should be appropriate to the size and layout of the building. The practice owner needs to demonstrate that staff have sufficient training in safely evacuating the premises and using firefighting equipment. An emergency plan is required to describe what action employees should take, warnings, calling the fire service, evacuation, assembly point, escape routes, responsibility of nominated people, machinery and power shutdown, and training. Practice electrical equipment All equipment within the dental premises must be installed, maintained and serviced by a suitably qualified person according to the manufacturer’s written protocols. Additionally, all equipment must be maintained with written protocols for use with appropriate training and supervision to ensure health and safety at work. In this section we will cover: • • • • Electrical inspections Computer and Visual Display Units (VDUs) Autoclave and air conditioning units Lasers. Electrical inspections The Electricity at Work Regulations 1989 covers both the safety of the fixed electricity supply to the dental practice and any portable electrical devices within the practice. A portable device is defined as any item with a cable and plug, which can be moved easily. It also includes devices which could be moved if required, e.g. photocopiers, printers, computers, etc. It is not mandatory to keep records of testing and inspections, but they do provide proof that all steps have been taken to comply with the 1989 regulations. Visual inspections Visual inspections are the most basic and essential check of electrical equipment, most safety defects can be found by visual examination and can be carried out by any competent and adequately trained member of the team or a qualified electrician. The plug and cable can be inspected for the following: • • • • Damage to the plug including cracks, loose pins Damage to the cable including exposed wires, breaks Overheating of plugs and cables Ensuring the cable is not trapped or pinched as it passes to or into the device. http://dentalebooks.com 146 • C L I N I C A L D E N T I S T RY Devices must be checked to ensure that: • There are no obvious casing fractures, loose screw or parts • They are being used for and within the correct environment (wet or dry conditions). Portable Appliance Testing (PAT) PAT is the term used to describe the combined examination and testing of electrical appliances by qualified electricians at appropriate intervals, depending upon the type of equipment and the environment in which it is used. It is recommended that this is carried out every 3 years, with records kept for a further 3 years (CQC). Computers and Visual Display Units (VDUs) The HSE 1992 (Display Screen Equipment) regulations govern the use of computer and monitor displays within the dental practice, and require employers to minimize risks from working with VDUs. The following should be addressed: • A risk assessment for each work station should be carried out • Workstations must provide a comfortable working area, with consideration given to the desktop, chair, monitor and keyboard • Lighting should be optimal with provision of an antiglare screen if required • Eye tests, and glasses required for specific VDU work should be provided and paid for by the employer. Autoclaves and compressors All pressurized systems within the dental practice are governed by the Pressure Safety Systems regulations of 2000. The most obvious are autoclaves and compressors, but other items with a capacity of more than 250 Bar Litres, such as boilers, steam heating systems and compressed air systems are covered. All pressurized systems falling into this category and dental autoclaves must have: • A written scheme of examination drawn up by a competent person (usually manufacturer appointment inspection personnel) which is reviewed regularly • Records of the vessel examination (the CQC recommends 3 years) • For autoclaves the maximum safety examination period is 14 months, for other systems 26 months. Safety examinations are in addition to regular maintenance checks according to the manufacturer’s recommended service engineers. Safety hazards in relation to dental autoclaves include: • Explosive opening of an unsecured door • Violent opening of a door at the end of a cycle due to residual pressure http://dentalebooks.com P ractice m ana g e m ent • • • 147 Heat scalding Explosion of glass containers containing fluids. All pressurized equipment should: • • • • Comply with British Safety standards Have a safety valve to prevent over pressurization, a pressure gauge, a drainage system Have the maximum allowable pressure clearly marked Autoclaves with ‘quick’ opening doors should not be able to be pressurized unless the door is fully closed. Lasers There is an increasing use of lasers in dentistry for both hard and soft tissue surgery. Lasers are classified as class 1 to 4, depending on their power output. Dental lasers are class 3b or 4 and must only be used under trained supervision. All laser practitioners must: • • • • • • Apply for registration as a user of a surgical laser with the Healthcare Commission Demonstrate the use of physical barriers to safeguard safety – controlled area, limited access Demonstrate appropriate training by all involved in laser use, local rules, and a record of laser use Demonstrate the suitability of laser for clinical use, machine maintenance, and laser safety eye protection Record and audit unwanted effects associated with laser use Obtain informed consent from patients undergoing laser surgery. Dental radiographs and regulations (see Chapter 8) The effective and safe use of dental X-ray equipment is paramount to the protection of the patient, members of the public and the dental team. The risks associated with exposure to ionizing radiation may be significant, and must be minimized through meticulous adherence to good practice protocols. The following points are not intended to cover all aspects of the various guidance notes and legislation. The various publications mentioned, particularly the 2001 Guidance Notes and the 2013 Selection Criteria, should be regarded as essential reading for all members of the dental profession, whether in general practice, dental hospitals or community clinics. The 2010 CBCT (Cone Beam Computerized Tomography) Guidance is essential reading for all involved with CBCT equipment. Dental X-ray recommendations were issued in 1991 from the International Commission on Radiological Protection, and as a http://dentalebooks.com 148 • C L I N I C A L D E N T I S T RY result, revised Euratom Directives were published which addressed the protection of patients in 1997 and workers and the general public in 1996. These Directives had to be implemented by member states of the EU by 13 May 2000, and led to the creation of two new sets of statutory regulations within the UK. The Ionising Radiations Regulations 1999 (IRR99) These relate principally to the protection of workers and the public, but also address the equipment aspects of patient protection. The HSE has published an accompanying Approved Code of Practice and associated Guidance. The Ionising Radiation (Medical Exposure) Regulations 2000 (IRMER) (Amendments 2006 and 2011) These relate to patient protection. Supporting guidance and notes on good practice are available on the Department of Health’s website (https://www.gov.uk/government/publications/the-ionising -radiation-medical-exposure-regulations-2000). Legal responsibility and staff appointments Legal Person Responsibilities under the IRR99 relate to an ‘employer’ and a ‘radiation employer’, whereas IRMER 2000 uses only ‘employer’ with a definition based on the concept of responsibility rather than employment law. What matters is that there is a clearly defined person or body corporate that takes legal responsibility for implementing both sets of regulations and good working practice. This is usually the practice owner. Radiation Protection Supervisor The Legal Person must appoint one or more Radiation Protection Supervisors (RPSs) whose function is to help in ensuring compliance with IRR99 and implementing the Local Rules within the controlled area. RPSs must have received appropriate training and can be a dentist or another dental care professional, such as a dental nurse or hygienist. Whoever is appointed as an RPS should have the authority to adequately implement their responsibilities. IRMER practitioner An IRMER practitioner is a registered dentist or DCP who is responsible for justifying an X-ray exposure, and ensuring that the benefits outweigh the risks. http://dentalebooks.com P ractice m ana g e m ent • 149 IRMER referrer An IRMER referrer is a dentist or DCP who is entitled to refer individuals for medical exposure to an IRMER practitioner (see above). The referrer can be either a dentist or dental hygienist/therapist. Operator An operator is any person who carries out all or part of the practical aspects associated with a radiographic examination, including: • • • • • • patient identification, positioning the film, the patient and the X-ray tube head setting the exposure parameters, software manipulation pressing the exposure button to initiate the exposure processing films clinical evaluation of radiographs exposing test objects as part of the QA programme. Because of the range of functions carried out by operators, it is essential that the functions and responsibilities of individual operators are clearly defined by the Legal Person. Under current GDC guidelines, registered dental hygienists and therapists are able to take on the roles as operator, practitioner and referrer. However, only dentists can ‘report’ on all aspects of a radiograph. Independent DCP practices therefore need to ensure appropriate referral systems are in place to ensure patients receive advice and treatment. External appointments Radiation Protection Advisor (RPA) An RPA must be appointed in writing by the Legal Person to provide advice on compliance with legal obligations of IRR99. The person or organization that provides routine radiation surveys of the dental equipment would normally be expected to be able to act as RPA. The Legal Person is recommended to obtain key RPA advice in written format since this provides firm evidence that consultation has taken place. As a result of the legal obligations of IRR99 and IRMER, the legal person (dentist) must: • • • Draw up an inventory of all X-ray equipment, including make, model, age and serial number. Notify the Health and Safety Executive. Submit plans for the installation and acceptance into service of new or modified dental X-ray equipment, with particular respect to any engineering controls, design features, safety features and warning devices provided to restrict exposure to ionizing radiation. http://dentalebooks.com 150 • • • • • • • • C L I N I C A L D E N T I S T RY Ensure that all equipment is routinely serviced and a radiation safety assessment is carried out at least every 3 years. Complete a risk assessment in conjunction with the RPA to limit exposure to staff and patients. This must be reviewed and documented every 5 years. Design a set of local rules, including the name and contact details of the RPA, operating instructions, details of controlled areas, and contingency plans in the case of equipment failure. Identify designated controlled areas. This is usually within a radius of 1.5 m, except in the direction of the beam. Appoint a RPS. Complete a radiation protection file collating the local rules and all documentation relating to radiation protection within the practice. Keep radiation dose As Low As Reasonably Practicable (ALARP). This involves: • Be able to justify each radiograph • A written guidance for exposure settings for all types of radiographs • A system of clinical evaluation and reporting in the patients’ notes • A quality assurance program to increase diagnostic yield and reduce repeat X-rays • Rectangular collimation with minimum skin to focus distance • The routine use of film holders. Dental Cone Beam Computerized Tomography (CBCT) Although CBCT in dentistry is governed by IR99 and IRMER regulations as above, because radiation doses from CBCT can be significantly higher than conventional dental X-ray equipment, specific guidance on the Safe Use of Cone Beam CT (Computed Tomography) in Dentistry has been published by the Health Protection Agency in 2010. Justification Before a CBCT can be taken, it must be justified by an IRMER practitioner and authorized by a written or electronic authorization. Justification of a CBCT exposure depends on: • • • The availability and findings of previous conventional dental X-rays. The specific objectives of the exposure in relation to the dental history and examination. The potential benefit to the patient vs. the radiation risk. http://dentalebooks.com P ractice m ana g e m ent • 151 CBCT training At present the minimum initial training requirements for referrers, practitioners and operators are as follows: • • • • Theory – 3 hours Radiological interpretation – minimum of 3 hours Practical training – 6 hours Refresher training (as part of verifiable CPCD) – 1 hour. This CBCT training is in addition to that already required as part of continuing education and training in dental radiology and protection. Building design The design of dental practices has changed markedly over the past decade, with contemporary dental clinics incorporating a large variety of aesthetics designs and ergonomic features that allow for a calm and relaxing patient experience, yet providing an efficient and productive clinic setting. At the heart of these design features is an ergonomic understanding of the interplay between the clinical and non-clinical areas of the dental clinic. However, irrespective of the final design and eventual market that the practice is aimed at, there are certain design features that are subject to external regulations, and should be incorporated to allow an ergonomic workflow within a dental practice. The Disability Discrimination Act (DDA) means that there must be easy access to the facilities, so wheelchair and bariatric patient access must be considered, not only to the building but also to facilities within (e.g. toilets). Basic design features All working environments should have the basic requirements: • • • • • • • There must be a clean and continuous supply of fresh air, either via open windows or via mechanical ventilation (5–8 litres/ second of air per occupant) Adequate lighting must be provided suitable for tasks undertaken Room dimensions should allow for the comfortable movement of all staff and patients Comfortable seating and sufficient area should be provided for all workstations Team members should have adequate washing and changing areas Adequate toilet facilities for team members and public Appropriate areas for team members to eat, drink and relax. http://dentalebooks.com 152 • C L I N I C A L D E N T I S T RY Ergonomic design The concept of dual flow within the practice should be adopted, whereby the patients circulate around the outside of the clinical areas, and the staff circulate around a central sterilization area. This helps to foster a calm atmosphere within the practice and increase efficiency. Reception and waiting areas Waiting areas should reflect the ethos of the practice in their design and décor. Many contemporary clinics allow form to follow function and create a welcoming, bright, uncluttered, non-threatening reception area that reflects the standards of the rest of the practice. Care should be taken to avoid accidents such as children playing behind doors, or trips over flooring or down steps, etc. Non-clinical consultation rooms The inclusion of separate non-clinical consultation areas for use by the patient care co-ordinator should be incorporated. These areas do not have to be large, and must be away from intimidating clinical areas to allow for the discussion of the patient’s history, problems, treatment plans, concerns, financial arrangements and any other matters pertaining to the patient’s dental experience. This area is as productive as any clinical area and will increase patient treatment acceptance. Clinical areas HTM 01-05 originally published in 2009 (amendments 2010, etc.) was designed to give comprehensive guidance on the design and provision of an optimal environment for safe and effective dental instrument decontamination. HTM 01-05 therefore has a direct influence on the design of surgery and decontamination areas. Best practice requires the environment for decontaminating instruments to be separate from the clinical treatment area. Essentially, this will require separate areas or rooms for ‘dirty’ and ‘clean’ instruments. Although not mandatory, the use of a mechanical washer/disinfector is best practice, and instruments will need to be stored away from the clinical treatment area. Implications of HTM 01-05 to the design of dental practices • Contaminated instruments require processing in a separate space from treatment areas • The decontamination area must be separated into dirty and clean zones • Sinks in the dirty zone have drainage for scrubbing and rinsing instruments http://dentalebooks.com P ractice m ana g e m ent • • • • • • • • 153 Clean zone has sink designated solely for hand washing and designed for that purpose Dirty zone has instrument washer/disinfector (W/D) (an ultrasonic cleaner is an optional item in addition to a W/D) No contaminated instruments or personnel should ideally pass through the clean zone A dirty to clean workflow should be maintained Where possible, air movement should be from clean and storage areas to dirty area Allow for adequate uncluttered worktops Provide ample clean storage. Design features of the whole dental practice for cross infection control • • • • • Smaller surgeries make room for a decontamination area. A standard surgery need not be any bigger than 3.4 m × 2.75 m (11 ft × 9 ft). Anything more makes it less efficient. Twin surgeries allow time for cleaning. Start working on the next patient in a clean surgery, allowing time to clean the empty surgery properly. Multiple doors to surgeries ease direction of flow of contaminated instruments, separate staff from patients and help nurture a calm environment. Minimize worktops. The less worktop, the less to clutter and the less to clean. Avoid clutter. Steri-walls (Sterilization walls) The concept of ‘Steri-Walls’ has been developed over the past several years to efficiently store everything that is needed during dental surgery. They reduce the amount of clutter in the surgeries, and can allow a transfer of clean and dirty instruments to and from the surgery to the decontamination area. The steri-walls can be colourcoded with red for dirty instruments and green for clean instruments, ensuring a positive workflow. Cross infection prevention Cross infection can potentially occur between patients, dentists and staff within the clinical area and is the transmission of infectious agents between these groups. Potential agents include mainly viruses (HIV, HSV, Hepatitis viruses) and bacteria (e.g. Streptococcus pyogenes), with transmission occurring by either direct or indirect contact, inoculation or sometimes inhalation. Prions have also become a consideration and fungi can be an issue. http://dentalebooks.com 154 • C L I N I C A L D E N T I S T RY All dental surgeries have a legal requirement (HTM 01-05 2013, CQC, GDC) to implement safe working protocols with respect to crossinfection control and decontamination. Every practice must have comprehensive cross-infection control protocols which identify the procedures to be followed by all members of the team. These procedures must be regularly reviewed, audited, updated, discussed, understood and implemented by each team member. The BDA recommends the following: • • • • • • • • • • • • An up-to-date, annual, cross-infection control policy must be in place and made known to all team members. Universal procedures must be adopted for all patients; healthy carriers of infectious diseases cannot be readily identified, therefore all patients are treated as infectious. All team members should have documented training in crossinfection prevention, including knowledge of transmission routes, sterilization and decontamination procedures, the use of Personal Protective Equipment (PPE) and hand hygiene. Surgeries and decontamination areas should be designed with separate ‘clean’ and ‘dirty’ areas to facilitate the workflow of contaminated clinical items. All surgeries should be well ventilated, with a one-way air flow and high speed aspiration used at all times. Uncluttered clinical surfaces must allow for easy cleaning and minimize the number of surfaces to be touched, e.g. taps and lights with infrared controls. Care is required to prevent needle-stick or other sharps injuries. The clinician should be responsible for needle removal. Needles should never be re-sheathed or re-capped. Rigid, yellow sharps containers must be used and not filled to more than two-thirds full. A disposal contract must be in place. Disposable, single use instruments (all endodontic files/reamers) should be used wherever possible. All re-usable instruments must be visibly clean (assisted by a magnification loop and good quality lighting), free from blood, saliva and debris before being sterilized and stored according to national guidelines. The effective pre-sterilization cleaning can be carried out using manual cleaning/ultra-sonic water bath or via a washer disinfector. Sterilization should take place in an autoclave at 134°C to 137°C for a minimum of 3 minutes. All decontamination and autoclave equipment should be regularly maintained, tested and validated (protein residue tests, http://dentalebooks.com P ractice m ana g e m ent • • • • 155 autoclave strip tests) according to the manufacturer’s written scheme of examination. Autoclave reservoirs chambers should be thoroughly cleaned and drained at the end of each day. Designated hand washing sinks must be allocated in both surgeries and decontamination areas. Clinical waste should be separated and disposed of according to national guidelines. Personal Protective Equipment (PPE) and Infection Control Protocols • • • • • Single use disposable gloves (powder free/low protein) face and eye protection are required for all clinical procedures. Clinical clothing should only be worn within surgeries and not outside the practice. Hand washing regimes should be carried out before and after each clinical session, before and after removing PPE, after washing instruments and after instrument decontamination procedures. Heavy duty gloves, disposable aprons and protective eye wear should be worn during decontamination procedures. Inoculation injuries must be dealt with immediately in accordance with practice protocols. Sharps safety and needle-stick injuries Sharps safety is governed by The Health and Safety Regulations 2013 (Sharps instruments in Healthcare). The following must be implemented: • • • • • • • • • • The handling of sharps must be kept to a minimum. Syringes or needles should only be dismantled by a dental clinician and disposed of as a single unit straight into a sharps container. Ideally sharps containers should be wall-mounted on the dentist side, as close as possible to the point of use. All sharps containers should conform to UN standard 3291 and British standard 7320. Needles should never be re-sheathed or re-capped. Needles should never be bent or shaped before or after use. Sharps containers must not be filled to more than two-thirds. Sharps containers must be signed on assembly and disposal. Sharps containers must be stored safely away from the public and out of reach of children. Staff should report sharps injuries in line with local reporting procedures and policies. http://dentalebooks.com 156 • • C L I N I C A L D E N T I S T RY Staff must be trained regarding the safe use of sharps and safety devices. Work surfaces • • • Instruments should be placed on a sterilizable tray in the clinical area. Equipment handles, lights, curing lights, tubing and controls should be covered by proprietary plastic covering. All dental surfaces and non-sterilizable equipment should be cleaned and disinfected with a suitable viricidal, bactericidal and antifungal disinfectant according to the manufacturer’s instructions. Immunization • • All clinical staff must have the routine immunizations, and also be inoculated against hepatitis B and tuberculosis. Primary Hep-B inoculation is followed by a single booster after 5 years. Records of inoculation and immune status must be documented for all staff. Staff should also be inoculated against other common illnesses, e.g. ’flu or chickenpox according to local primary care authorities. Blood spillages • • Blood spillages should be immediately covered with disposable towels and covered with 10000 ppm sodium hypochlorite solution. After 5 minutes, using disposable, heavy gloves, the towels should be disposed of in clinical waste. Laboratory impressions and clinical appliances • • • All impressions and appliances should be rinsed, disinfected and bagged according to the manufacturer’s instructions before sending to the laboratory. The lab sheet should be marked to show that appropriate disinfection has been carried out. On return to the surgery all clinical appliances should be marked disinfected by the lab protocols. Time management Running late in the dental surgery can be stressful and counterproductive to the whole dental team and can affect the quality of patient care. Over running appointment times are a consequence of http://dentalebooks.com P ractice m ana g e m ent • 157 a poorly organized day book, poor communication and the overestimation of clinical ability. Clear protocols are required in practice to manage the day book with specific guidelines on how to deal with the late arrival of patients, unplanned emergencies and insufficient or inappropriate appointment times. As ever, communication between the reception team and the clinical team is essential to allow for efficient and stressfree time management in the dental surgery. Where there is a continued problem with over running of appointments then the team should reassess and examine working protocols. Identify the reasons why the clinics run late; Clinics not starting on time, insufficient time booked for specific procedures, late arrival of patients, clinicians attempting over-ambitious treatments in short time periods. Should time keeping be a persistent problem in the practice then the underlying reasons must be identified; only then can protocols be put in place to manage the over-runs. The following should be implemented: • • • • • • • • • • • • The appointment book should allow emergency sessions each day and the reception team should understand the definition of an emergency patient/appointment. The appointment book should be divided into 5-minute slots, with realistic treatment times booked, tailored to each member of the clinical team. Appropriate time must be allowed for the setting up of surgeries and clearing down after all treatments. Complex or demanding treatments should be arranged for the morning session, with minor procedures in the afternoon (e.g. exams). Do not book demanding, complex dental procedures back to back. Do not try to carry out dental treatment that was not planned for that appointment. Communication is essential. Ensure the reception team and patients are kept informed of any delays. Reschedule appointments where necessary. Identify late attenders in the practice and arrange for them to come in earlier, or ring in advance of their appointments. Delegate relevant tasks to other team members, e.g. nurses, hygienists and therapists. Plan individual days for large complex treatments e.g. cosmetic smile make-overs, implants, etc. Clearly define the working day and do not extend beyond this. Instil a team culture of running to time and adopt as a core practice value. http://dentalebooks.com 158 • C L I N I C A L D E N T I S T RY The definition of an emergency patient needs to be made clear for the whole clinical team, and is a patient who is willing to attend at any time due to acute trauma, pain or bleeding. Patients outside of this remit are not a true emergency. Again communication is essential between the reception and clinical team to assess if other ‘emergency patients’ will be allocated emergency sessions, e.g. cosmetic or orthodontic issues. Dental Foundation Training, Dental Core Training and Dental Career Development Posts (DCDP) For most newly qualified dentists, Dental Foundation Training (DFT) and Dental Core Training (DCT) are the next obligatory steps on their professional pathway in dentistry. National recruitment to DFT (formerly Vocational Training) was introduced for dental graduates entering in 2012. The recruitment process is led by Shared Services on behalf of Health Education England and The Committee of Postgraduate Dental Deans and Directors (COPDEND). COPDEND is currently developing a revised curriculum and assessment framework for Dental Foundation Training that will apply for schemes commencing on or after September 2015. Dental Foundation Training (DFT1) Dental Foundation Training lasts for 1 year and can be carried out in specially appointed Training Practices fully funded by the NHS), where approved, experienced general dental practitioners, with more than 4 years’ experience and who have an ability to teach and help new dentists are appointed as Trainers. • • • • • • • The practice must provide the Foundation Dentists (FDs) with a fully equipped surgery, a dental nurse, and patients. The foundation dentist works in the practice for a maximum of 35 hours per week (28 hours during day release courses). The Trainer must be available to provide help and advice, be it chairside or otherwise, and also has to provide a weekly tutorial lasting one hour, during normal working hours. The training dentist must be present not less than 3 days a week. The trainers are themselves trained in teaching and assessment roles. A grant is paid to the training practice and the trainees’ salary is reimbursed in full. Trainees are also required to attend a specified number of study days over the 12 months to further expand their knowledge and experience. http://dentalebooks.com P ractice m ana g e m ent • 159 DFT is not designed to produce a ‘practice owner’, or equip Foundation Dentists with the skills required to set up and run a dental practice, but rather prepare individuals for independent practice as an associate/performer/employee within the General Dental Services. Dental Foundation study days The Training Practices are attached to a Foundation Scheme, and in charge of each Scheme is a Training Programme Director (TPD). • • • Dental Foundation Training lasts for 1 year commencing on the 1 September, and during this period the FD attends a minimum of 30 days’ Day Release Course (DRC) at the Scheme centre. Each FD has an on-line e-portfolio, which is used as an educational aid throughout the year. The Trainer works with the FD and the Portfolio to produce action plans and regular assessments of development. The aims and objectives of the study days are: • • • • • To enable the dental practitioner to practise and improve the dental practitioner’s skills To introduce the dental practitioner to all aspects of dental practice in primary care To identify the dental practitioner’s personal strengths and weaknesses and balance them through a planned programme of training To promote oral health of, and quality dental care for, patients To develop and implement peer and self-review, and promote awareness of the need for professional education, training and audit as a continuing process. Contracts and completion of DFT Standard contracts, available from both the BDA and FDT schemes, are signed by both parties, with the contract running for 12 months. At the end of this contract each party is free to make their own arrangements, however the contracts usually incorporate bindingout and under performance clauses – separate legal advice should always be sought. On completion of 1 year of Dental Foundation Training, FDs are eligible to apply for, and obtain, an NHS Performers List number; this enables them to treat NHS patients. Many FDs stay on in general dental practice, whilst others undertake Dental Core Training jobs in hospital. Dentists who have not completed DFT Dentists who do not have a Vocational Training Certificate, or who have not completed an appropriate period of Vocational Training as defined in the Regulations, must be assessed by the Area Team in http://dentalebooks.com 160 • C L I N I C A L D E N T I S T RY consultation with the Postgraduate LETB to decide whether the dentist can be admitted to the list based on having previous experience and training including NHS primary dental care. From April 2013, Deaneries ceased to exist and are now part of Health Education England’s Local Education and Training Boards. PCTs also ceased to exist and in their place, NHS England (formally the NHS Commissioning Board) now manages a National Performers List. Applications to join this national list are now managed by local branches of NHS England, known as Area Teams. Who may need to be admitted by assessment? • Dentists who do not have a Vocational Training Certificate • Dentists who have not completed, or who are not undertaking, Vocational Training • Dentists who do not qualify for exemption under para 31 (5) of the Performer List Regulations which state that: a. They are a national of a member state of the European Economic Area other than the United Kingdom with a diploma recognized by the General Dental Council; or b. They have practised in primary dental care for a period of at least 2 years in aggregate in either the Community Dental Service, the armed forces or Personal Dental Services (PDS) prior to 1st April 2006. Dental Core Training posts Dental Core Training posts (DCT1 – previously known as dental foundation year 2) are 1-year training programmes following on from Dental Foundation year 1. The year is commonly split into two 6-month rotations with placements at hospital sites or salaried primary care dental service (SPDCS) clinics. DCT2 and DCT3 posts further allow trainees to acquire additional skills in particular specialty areas (see Table 6.1). As a DCT1 you will be issued with a LET employee handbook which will give detailed contractual information. The LET retain the employment responsibilities in your contract. However, in practice your day to day supervision and appraisals will be carried out by your host training trust. Dental Career Development Posts (DCDP) DCDP are being developed at the level of year three post-graduation to allow dentists to consolidate experience gained in foundation training and to help them gain taster experience in specialty areas that may not have been available to them during foundation training, http://dentalebooks.com P ractice m ana g e m ent • 161 TABLE 6.1 Dental Core Training at a glance Training post name Previously known as Comment Dental Foundation Vocational training Trainees will be referred to as ‘Foundation dentists’ DCT Level 1 DF2, GPT (Hospital element) Linked to the original DF 2-year curriculum. Follows on from Dental Foundation Training or constitutes the hospital element of the 2-year GPT programme. DCT Level 2 SHO For trainees who have completed DCT Level 1 (or its equivalent) For trainees new to hospital dentistry. For trainees previously in a DCT Level 2 post who are not joining a dental specialism pathway. DCT Level 3 CPD For trainees in an existing DCT Level 2 post or equivalent who have an individual learning plan as part of a dental specialism pathway. for example: Paediatric Dentistry, Restorative Dentistry, Oral Surgery, Oral Medicine, Oral & Maxillofacial Pathology, Orthodontics or Dental Public Health. The aim of these posts is to help foundation dentists consolidate experience already gained in DFT. Although these are still training and development posts, it is anticipated that DCDP dentists will be able to provide more service than those in DFT. Clinical governance, clinical audit, peer review and Continuing Professional Development (see Chapter 5) Clinical governance Clinical governance (CG) is an NHS framework to improve the quality of care patients receive and to maintain that high quality of care. CG is the responsibility of all dental team members to ensure that http://dentalebooks.com 162 • C L I N I C A L D E N T I S T RY patients receive the best possible care and ensures that all providers are accountable. Dental practices with an NHS contract must comply with CG arrangements as specified, at a National Level by their National Health Standards Body (CQC, RQIA, HIW, HIS) and at a local level by their Primary Care Contractor or local health board, although regional variations exist. In England, private dental practices are monitored by the CQC with respect to CG. Private dental practices within Northern Ireland are governed by the RQIA, and in Wales by the HIW. Private dental practices in Scotland, at present, are not monitored with respect to CG, although likely to be eventually governed by HIS. Main components of clinical governance • • • • • • Risk management Clinical audit CPD, education, training and peer review Evidence-based care and effectiveness Patient experience and involvement Staffing and staff management. Clinical governance effects the following areas of dental practice • • • • • • • • • • • Radiography Health and safety Communications/Consent Child and vulnerable adult protection Evidence-based practice Prevention Staff training and involvement Patient involvement Infection control Accessibility Quality assurance and self-assessment (audit, peer review) All Dental Practices, irrespective of location or type of service provided (NHS or private) should draw up a clinical governance framework which involves: • • • • • Designating an individual responsible for monitoring the CG systems Displaying a written statement relating to adopted quality assurance systems Implementing effective cross-infection control protocols Complying with legal requirements relating to radiation protection and health and safety Complying with CPD requirements of the GDC. http://dentalebooks.com P ractice m ana g e m ent • 163 Clinical audit and peer review (see Chapter 5) Clinical audit and peer review form a fundamental part of clinical governance and allows a systematic and critical analysis of the quality and effectiveness of patient care. It is the mechanism to demonstrate compliance with national and local quality standards bodies (CQC, HIW, HIS, RQIA). Clinical audit is carried out by individuals, whereas peer review involves collaboration between a small group of dentists (ideally 4–8). The aim of clinical audit and peer review in dentistry is to enable dentists to assess different areas of their practice, instigate changes and monitor them with the aim of improving service levels and patient care. Periodic review should be carried out to re-assess audited areas to ensure that the quality of service is being maintained or requires further improvement. Legal/Contract requirement Clinical audit or peer review is a contractual requirement of primary care contractors or local health boards, and dental practices should liaise closely with them to define local regulations, since there is a wide degree of national variation in audit requirements. Aims of clinical audit • • Improvement of quality of clinical care Identify areas of sub-optimal care. Audit outline • • • • A brief outline of the aims and objectives of the audit and the adopted standard A summary of the methodology, including details of data collection, sample size and method of data analysis Proposed timetable of audit Proposed educational reference material. Mechanism of clinical audit 1. Agreement of a ‘gold standard’ of care for a specific area 2. Retrospective analysis of care in that area 3. Analysis of findings of audit involving a frank and open discussion avoiding criticism 4. Identification of deficient areas 5. Suggest improvements 6. Agree to implement improvements 7. Prospective analysis of modified care 8. Re-analysis of ‘modified’ care vs. ‘gold standard’ http://dentalebooks.com 164 • C L I N I C A L D E N T I S T RY 9. If ‘gold standard’ met then adopt and undertake periodic review 10. If ‘gold standard’ not met then review procedures and repeat the audit. Possible topics for clinical audit include X-ray quality, cross-infection control, ID-block effectiveness, implant success/failure rates. The BDA website (https://www.bda.org/) provides a good source of information including topics for audit. Continuing Professional Development CPD is a compulsory requirement for registration with the GDC. It is defined as lectures, seminars, courses, individual study and other activities that can be included in your CPD record if it can be reasonably expected to advance your professional development as a dentist or DCP and is relevant to your practice or intended practice. A CPD cycle lasts 5 years and a minimum amount of verifiable and non-verifiable CPD is required. For dentists 250 hours of CPD every 5 years: • • At least 75 hours need to be verifiable, e.g. approved courses At least 175 hours non-verifiable, e.g. professional journal articles/books/Internet, etc. Core CPD topics in the 5-year cycle have been specified by the GDC: • • • • • • Medical emergencies (10 hours) Disinfection and decontamination (5 hours) Radiography/radiation protection (5 hours) Legal and ethical issues Complaints handling Oral cancer: early detection. For DCPs 150 hours of CPD every 5 years: • • At least verifiable 50 hours At least 100 non-verifiable areas. A full record of CPD activity must be kept, including a description of the CPD type and documentary evidence. Records can be requested by the GDC and failure to comply can result in removal from the register. Personal Development Plan (PDP) The GDC recommends a personal development plan to organize and structure CPD activity. A PDP does not need to be elaborate; it should consist of: http://dentalebooks.com P ractice m ana g e m ent • • • • • • • • • 165 Your name Date of creation of plan Identification of training needs Reasons for identifying these training needs Prioritization of training needs The format of training, e.g. formal course or online study Date of completion Periodic review of training plan. References Control of Substances Hazardous to Health Regulations (COSHH), 2002. SI 2002 No 2677. HMSO, 2002. <http://www.legislation.gov.uk/uksi/2002/2677/ contents/made>. Council Directive 97/43/Euratom of 30 June 1997 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure, and repealing. Directive 84/466/Euratom Official journal L180, 09/07/1997, 22–27. CQC The fundamental Standards. <http://www.cqc.org.uk/content/fundamental -standards>. Data Protection Act, 1998. <http://www.legislation.gov.uk/ukpga/1998/29/pdfs/ ukpga_19980029_en.pdf>. Environmental Protection Act, 1990. Waste Segregation Part II. Section 34. <http:// www.legislation.gov.uk/ukpga/1990/43/section/34>. Guidance notes for Dental Practitioners on the Safe Use of X-Ray Equipment, 2001. NRPB DOH. <https://www.gov.uk/government/uploads/system/uploads/ attachment_data/file/337178/misc_pub_DentalGuidanceNotes.pdf>. Health and Safety (Sharp Instruments in Healthcare), 2013. HSE. <http://www.hse. gov.uk/pubns/hsis7.pdf>. Health and Safety at Work Act, 1974. HMSO, 1974. <http://www.legislation.gov.uk/ ukpga/1974/37/pdfs/ukpga_19740037_en.pdf>. Health Protection Agency (HPA), 2010. Guidance on the Safe Use of Dental Cone Beam CT (Computed Tomography) Equipment. Chilton. HPA., Oxford. <https:// www.hpa-radiationservices.org.uk/dxps/resources/>. Health Technical Memorandum 01-05, 2013. Decontamination in primary care dental practices. <http://www.gov/government/uploads/system/uploads/ attatchment_data/file/170689/HTM_01-05_2013.pdf>. Northern Deanery Programme Dental Core training at a Glance. NHS. <http:// nor ther ndeanery.ncl.ac.uk/Nor ther nDeanery/dentistry/dental-dhso -programme/DentalCoreTrainingAtAGlance.pdf>. Pressure Systems Safety Regulations, 2000. SI 2000 No 128. HMSO. <http://www .legislation.gov.uk/uksi/2000/128/contents/made>. Recommendations of the International Commision on Radiological Protection, 1991. IRCP Publication 60, 21 (1-3) <http://www.icrp.org/publication.asp?id =icrp%20publication%2060>. Reporting of Injuries, Diseases and Dangerous Occurences Regulations (RIDDOR), 2013. HSE <http://www.hse.gov.ul/pubns/indg453.pdf>. Selection Criteria for Dental Radiography. 1st Edn 1998, 2nd Edn 2004, 3rd Edn 2013 published by the Faculty of General Dental Practice (UK) of the Royal College of Surgeons of England. The Electricty at Work Regulations, 1989. HSR25-HSE. <http://www.hse.gov.uk/ pubns/books/hsr25.htm>. http://dentalebooks.com 166 • C L I N I C A L D E N T I S T RY The Ionising Radiation (Medical Exposure) Regulations, 2000. SI 2000/1059. HMSO, London. <http://www.legislation.gov.uk/uksi/2000/1059/contents/ made>. The Ionising Radiations Regulations, 1999. SI 1999/3232. HMSO, London. <http:// www.legislation.gov.uk/uksi/1999/3232/contents/made>. The Regulatory Reform (Fire Safety) Order, 2005. <http://www.legislation.gov.uk/ uksi/2005/1541/pdfs/uksi_20051541_en.pdf>. Work with display screen equipment: Health and Safety Equipment) Regulations 1992 as amended by the Health and Safety (Miscellaneous Amendments) Regulations, 2002. <http://www.hse.gov.uk/pubns/books/l26.htm>. http://dentalebooks.com History and examination History 167 Examination 171 7 Diagnosis 172 Treatment planning 173 History This chapter outlines the general principles of taking a history, conducting an examination and, having made a diagnosis, formulating a treatment plan. Details relating to specific clinical circumstances are expanded in subsequent chapters. The purpose of a history Taking a good history is an essential first step in the diagnosis and management of any dental condition. The aim is to establish a rapport with the patient and to obtain an accurate account of individual concerns and circumstances which, following examination, will enable a diagnosis to be made and a treatment plan formulated with the patient’s consent (Figure 7.1). Patients often divulge information to dental nurses rather than to the dentist, so liaise closely with them. First impressions are very important. The patient will be apprehensive and probably very nervous but will be reassured by seeing a well groomed smartlydressed clinician. Always fetch the patient from the waiting area yourself, and ask for them by title and surname. In the event of patients having the same name, check the date of birth discreetly. Shake the patient’s hand, but be sensitive to ethnicity and cultural background – it is the first stage of building trust and confidence. The patient may have a companion to help especially if there are disability or language difficulties; the companion should also be invited to come to the clinical area. Always ensure you are chaperoned. Take time to seat the patient comfortably and ask questions in an unhurried way. Patients will probably not remember your name so write it down for them. Many patients have difficulty recalling anything about their visit so make notes for them especially if giving instructions. Give them printed information sheets to take home and discuss with their relations and friends. Whilst numerous schemes for obtaining a history have been described, information is gained with maximal efficiency by following a routine and systematic mode of enquiry. http://dentalebooks.com 168 • C L I N I C A L D E N T I S T RY Figure 7.1 Government guidance on consent <www.gov.uk/government/ publications/reference-guide-to-consent-for-examination-or-treatment -second-edition>. Presenting complaint Any history should begin with an invitation to the patient to explain the main problem or reason for attending, to indicate what is worrying the patient and help establish rapport by showing empathy. Patients are often poor historians; thus there is a need to direct the history by asking specific questions related to the history of the presenting complaint. If there is more than one complaint, try to establish the patient’s main concern. Avoid leading questions. History of presenting complaint (HPC) Having established the patient’s main concern, enquiry into the history of the problem provides valuable clues. The presenting complaint should be recorded by using the patient’s own terms as much as possible. It is also necessary to establish the nature of the problem, e.g. is it: • • • • • • pain, discomfort or merely an abnormal feeling? an aesthetic problem? altered function? bleeding or exudate? swelling? halitosis? Determine • When was the problem first noticed? • Is it continuous or intermittent? • If intermittent, how frequently does it occur? • Are there any initiating or relieving factors? • Is the problem becoming worse, better, or about the same? problem? • Where exactly is thehttp://dentalebooks.com H ist o ry and e x a m inati o n • 169 If pain is described as the main problem, the following must be established: Location. Specific tooth or generalized. Initiating or relieving factors. Hot/cold, worse on biting, worse on bending forwards. Character. Dull, sharp, throbbing, shooting. Severity. For example causing sleep loss, relieved by mild analgesics. Spread/radiation. To adjacent structures, referred pain. Remember, pain thresholds vary greatly between individuals. Previous dental history (PDH) Establish • Previous episodes of similar nature • Regular/irregular dental attender • When patient last received dental treatment • Attitude to dental treatment – anxious, relaxed. Previous medical history (PMH) Knowledge of a patient’s general health is essential and should be obtained before examination. It is best obtained by questionnaire (Table 7.1). This emphasizes the routine nature of enquiry into medical history as some patients fail to appreciate the relevance of general health to dental treatment. Older patients and those with language or literacy problems may need help in completing the questionnaire. Clarify any areas of uncertainty. This part of the history should be updated routinely at each patient visit. Even when a questionnaire has been completed with no positive response, it is worth asking a general screening question of the patient such as, ‘Are you generally fit and well?’ or ‘Are you attending any doctors or clinics or taking any medicines or tablets?’ It is the clinician’s responsibility to ensure that an accurate medical history has been obtained prior to commencing an examination. It is safe to assume that most patients, particularly older ones, have more health problems other than the obvious dental one. Take time to listen carefully to the patient and gently pursue any hesitancy or reluctance to talk about these. As a professional in health care you are entitled to honest answers. http://dentalebooks.com 170 • C L I N I C A L D E N T I S T RY TABLE 7.1 Relevant questions in a medical history Details Yes No Do you feel generally healthy? □ □ Have you had rheumatic fever or infective endocarditis? □ □ Have you had hepatitis or jaundice? □ □ Do you have any heart problems such as angina, heart murmur, replacement valve or have you suffered a heart attack? □ □ Do you have high blood pressure? □ □ Do you suffer from bronchitis, asthma or any other chest condition? □ □ Do you have diabetes? □ □ Do you have arthritis? □ □ Have you ever had any infectious diseases such as hepatitis, HIV, TB or other infectious disease? □ □ Are you receiving any tablets, creams or ointments from your doctor? □ □ Are you using any tablets, creams, ointments, powders or medicines bought ‘over the counter’ in a pharmacy or shop? □ □ Are you taking, or have you taken steroids in the last 2 years? □ □ Are you allergic to any medicines, food or materials (e.g. latex)? □ □ Do you suffer from epilepsy or are you prone to fainting attacks? □ □ Have you ever bled excessively following a cut or tooth extraction? □ □ Are you pregnant? □ □ Have you been hospitalized? If yes, what for and when? □ □ Are you attending any other hospital clinics or specialists? □ □ Do you smoke? □ □ Who is your doctor? Social history (SH) Questions here relate to factors likely to influence dental disease or availability for treatment. Thus it is desirable to establish: • • • patient’s age occupation marital circumstances http://dentalebooks.com H ist o ry and e x a m inati o n • • • • 171 dependants smoking habit alcohol consumption. A good history should help considerably towards a diagnosis even before physical examination of the patient is carried out. Examination At this stage it is necessary to make the transition from questioning the patient to physical examination. Give reassurance as this is a troublesome moment for anxious patients. Examination essentially begins when patients enter the surgery as much can be learned from their general demeanour. Do they look fit and well? Are they relaxed or apprehensive? The first few minutes of a consultation are important in establishing a rapport and communication between dentist and patient. Extraoral examination Look for • General appearance of patient • Swellings of the face and neck • Skeletal pattern • Lip competency • Temporomandibular joint (TMJ) problems. Palpate • Cervical lymph nodes • TMJ • Muscles of mastication. Intraoral examination It is reassuring to the patient to look initially at the presenting complaint as this emphasizes your role as a caring professional. Follow this by a systematic, detailed examination and note: condition of soft tissues, taking care to include lingual sulcus, floor of mouth, retromolar regions and record abnormal appearance, swelling, sinuses; teeth present, missing, unerupted; general state of the dentition; oral hygiene status; presence and site of restorations and carious lesions; presence and age of dentures; non-carious tooth surface loss, wear facets and ‘high spots’; periodontal condition; path of closure of the mandible, premature contacts, overerupted teeth, http://dentalebooks.com 172 • C L I N I C A L D E N T I S T RY intercuspal relationship, overbite, overjet; relation of the teeth in function – contacts on lateral and protrusive movements of the mandible. Diagnosis Provisional diagnosis From the history and examination a provisional diagnosis is made. This provisional diagnosis may be part of a differential diagnosis – whereby the most probable diagnosis is listed first, followed by other possible diagnoses. However, special tests or investigations may be required to confirm the diagnosis. Special tests and investigations Radiographs. Should be used only to obtain additional information to supplement clinical findings. Principles governing the taking of radiographs are detailed in Chapter 8. Intraoral radiographs expose the patient to very low doses of radiation but extraoral and especially cone beam computed tomography (CBCT) have much higher doses. Sensitivity (vitality) tests. Rely on stimulation of pulp either by application of thermal stimuli (e.g. ethyl chloride) or electrical stimuli. Measures response of pain receptors rather than testing blood flow. Can be complicated in multi-rooted or heavily restored teeth. Study models. Used to study occlusal relationships, design of bridges, partial dentures. Tests often sent for referral Biopsy. Allows histological examination of tissues. Blood tests. Important for some conditions (e.g. oral ulceration) and in patient management (e.g. INR for patients on warfarin; see Chapter 20). Ultrasonography Definitive diagnosis From the history, examination and special tests, a definitive diagnosis should be reached and recorded in the patient’s case record. Obviously there may be more than one definitive diagnosis in the same patient, e.g. dental caries, periodontal disease, toothbrush abrasion, and each should be clearly recorded. Never be embarrassed or too proud to ask for a second opinion even from one’s close colleagues. http://dentalebooks.com H ist o ry and e x a m inati o n • 173 Treatment planning The purpose of a treatment plan is to provide a work schedule. The following principles apply: 1. Relieve pain. It is crucial that any patient presenting in pain receives treatment aimed at pain relief. 2. Extract teeth of hopeless prognosis. However, extraction of asymptomatic teeth may be delayed, especially if patient is anxious (further treatment may improve confidence). Delaying extraction of anterior teeth may obviate the need for partial denture/bridge until oral hygiene has been improved. 3. Provide preventive advice. 4. Improve periodontal condition. 5. Restore carious teeth. 6. More advanced treatment procedures – endodontics, crowns, bridges, partial dentures. 7. Recall maintenance – the schedule for recall should be judged by disease risk status of the patient. The National Institute for Health and Clinical Excellence (NICE) has issued guidance on the frequency of recall for dental examination (see Chapter 1). Factors influencing treatment planning Many factors influence treatment options available in individual circumstances. Frequently a compromise must be achieved between what the patient wants and what is technically feasible. Factors influencing treatment include: Patient-related factors • complicating medical history • patient anxiety • inability/unwillingness to maintain adequate standards of plaque control • inability to afford time required for proposed treatment. Dentist-related factors • treatment options may depend on ability of dentist • access to specialist services. Cost-related factors • treatment available may depend on what patient can afford • availability of planned procedures under the healthcare system or insurance scheme covering patient’s treatment. Other factors in treatment planning Do not comment definitively on treatment until examination, special tests and diagnosis are complete • http://dentalebooks.com 174 • • • • • • C L I N I C A L D E N T I S T RY Formulation of a treatment plan requires consultation with patient to select the most appropriate and acceptable plan. Do not be judgmental: be prepared radically to modify the ideal. Patients vary greatly in the value they place on their dentition and sometimes dental treatment is a long way down their list of priorities In any complex treatment schedule build in contingency plans; allow for ‘what if?’ Good oral hygiene and adherence to preventive advice is of prime importance Work on one segment (e.g. quadrant) of the mouth at a time In anxious patients, carry out simplest treatment first. Reasons that warrant referral for a second opinion may include: • • • You are overwhelmed by the complexity of the dental problems Lumps in the mouth and neck and lesions of the oral mucosa. The term ‘index of suspicion’ is used to indicate how seriously a particular disease, notably neoplasia, is being entertained as a diagnosis. The consequences of missing neoplasia can be catastrophic so maintain a high index of suspicion. No senior clinician would criticize you for referring a patient with a problem that turns out to be benign. Complex medical or other history that may necessitate treatment modifications. In the case of people with medical, physical or/and mental health issues (see Chapter 20), preventive procedures, simple periodontal therapy, removable restorative work and orthodontics can often be carried out in primary care but the threshold for referral or seeking advice is lower than in people without these issues. The mechanism of referral is dependent on the perceived urgency. For example, a patient who has longstanding restorative problems could safely be referred to a specialist by letter, perhaps including radiographs. A patient with a serious infection of the soft tissues that may compromise the airway should be dispatched immediately to A&E with a brief handwritten note, perhaps by ambulance. Clearly it would be advantageous to alert the on-call staff by phone. There may be local arrangements for suspected neoplasia by a ‘fast track’ system involving fax, E-mail or simply phone and it is important that you know about the protocols (which should be available as part of a standing orders system in the practice) and always adhere to data protection protocols. http://dentalebooks.com Dental and maxillofacial radiology The nature of X-rays, their production and interaction 175 Image formation 177 Radiation dose measurement and radiation protection 179 Ionizing radiation regulations 185 8 Radiographic technique 186 Guidelines for the prescription of radiographs 192 Interpretation of radiographs 197 Differential diagnosis of radiographic lesions 199 Definition (GDC) Involves all aspects of medical imaging which provide information about anatomy, function and diseased states of the teeth and jaws. The nature of X-rays, their production and interaction X-rays form part of the electromagnetic spectrum together with radiation such as radio waves and light. Radio waves, which lie at one end of this spectrum, have a long wavelength but are of low energy; X-rays on the other hand have a short wavelength but are of high energy. X-rays were discovered in 1895 by Conrad Roentgen and were so-called because at that time the nature of the radiation was unknown. Later it was realized that X-rays were the same as gamma radiation. However, the beam generated by an X-ray tube (Figure 8.1) consists of X-ray photons with a range of different energies, whereas gamma rays that are produced by a radioactive source are of a single energy characteristic of the particular isotope. X-rays are produced in the X-ray tube by bombarding a tungsten target with a stream of electrons, accelerated by a high voltage (typically of 60–70 kV for an intraoral dental unit). The process is very inefficient, with only approximately 1% of the energy from the electron stream going into X-rays, 99% being lost as heat. The larger the voltage, the greater will be the maximum energy of the X-ray photons within the beam, increasing its penetrative power (Figure 8.2). http://dentalebooks.com 176 • C L I N I C A L D E N T I S T RY Electron stream Glass envelope Filament X-rays Tungsten target Copper block (to absorb heat) High voltage Figure 8.1 X-ray tube. Number of X-ray photons Low-energy X-rays removed by filtration Maximum energy Useful part of spectrum 0 10 20 30 40 50 60 70 Energy of X-ray photons (keV) Figure 8.2 X-ray spectrum produced at 70 kV. There will still be a range of energies, and this is of fundamental importance to the creation of a radiographic image, as it enhances the differential absorption of the beam by the different tissues of the body. However, very low-energy photons would be immediately absorbed by the skin. This would add to the patient dose without contributing to the radiographic image and consequently these photons are removed using an aluminium filter. http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 177 The current flowing though the X-ray tube (typically 8–10 mA) will determine the quantity of X-rays produced. The higher the current, the less time will be required for the exposure. However, many dental radiography sets have a fixed current, leaving the operator only to adjust the time. When X-ray photons enter the body, two main interactions occur: photoelectric absorption and Compton scatter. Photoelectric absorption The photoelectric effect predominates with lower-energy photons, the likelihood of this interaction occurring varying with the atomic number (Z) of the tissue. The probability is proportional to Z3; consequently there is a big difference between the absorption by bone (Z3 = 1728) and soft tissues (Z3 = 343), which is why there is good contrast between these structures on a radiograph. Compton scatter However, the probability of the photoelectric effect occurring is also proportional to 1/kV3, which means that it becomes less likely as the tube voltage is increased and as a result there is an increase in Compton scatter. This interaction gives poor contrast as it is not dependent on the atomic number of the tissue, and the scattering effect also reduces the image quality. Image formation Film-based imaging For intraoral radiography, imaging is done directly onto film with a lead foil backing to prevent unnecessary exposure of the deeper tissues. This has the advantage of giving an image with a very high resolution but, for the larger fields of view used in extraoral imaging, the dose using a film alone would be too high. Extraoral images therefore are taken using a cassette, which sandwiches the film between intensifying screens containing phosphor crystals. These fluoresce when exposed to the X-rays, producing light, which exposes the film in addition to the X-rays, allowing large fields of view to be imaged at an acceptable dose, but with a reduction in resolution compared to intraoral imaging. The intensifying screens contain rare earth elements such as gadolinium and lanthanum. Dental film has a double emulsion, i.e. on both sides, which increases its sensitivity and reduces the dose required. The emulsion is made up of silver halide crystals, 90% AgBr and 10% AgI. When the film is exposed, an electron is able to move within the crystal lattice and combines with a silver ion to form a deposit of silver. This http://dentalebooks.com 178 • C L I N I C A L D E N T I S T RY acts as a further trap for other electrons resulting in more silver being formed. The resulting pattern, which is invisible to the naked eye, is known as the latent image. Conventional wet film processing consists of the following stages: Developing • Developer is an alkali and acts as a reducing agent • It converts the Ag+ ions to deposits of silver by the addition of an electron • It preferentially reacts with the crystals which have already formed a deposit of silver. Intermediate washing This stops the action of the developer. Not required in many automatic processors which remove the developer using the squeezing action of the rollers. • Fixing Fixer is an acid which removes the un-reacted silver halide crystals. • Final washing This removes the fixer. Failure to do this eventually results in the formation of silver sulphide which causes the images to turn brown. • Drying Gives a dry film for viewing and prevents water marks. • Digital imaging This uses a conventional X-ray machine, but the film is replaced by either a sensor containing a Charge-Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (CMOS) which communicates directly with the computer; or a photostimulable phosphor plate which requires scanning before the image appears on the monitor. In both cases the information is stored as digital data sets on a computer and can then be reconstructed into a grey-scale image. Advantages No need for conventional processing; software allows image manipulation and enhancement; very efficient image storage and retrieval. Disadvantages The CCD and CMOS sensors can be bulky, making placement difficult which increases rejects rates; the phosphor plates do not give an http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 179 instant result, requiring a second scanning step, and they are prone to mechanical damage if not handled carefully; image manipulation can be misleading and can be misused. Generally the CCD or CMOS sensors are preferred for panoramic machines as these give superior image quality with a slightly lower X-ray dose, whereas the phosphor plate system is favoured for intraoral use as the plates are more easily placed in the patient’s mouth. Radiation dose measurement and radiation protection The measurement of radiation dose is quite complex. Of particular interest is the assessment of the detrimental effect of a given procedure. To express this, several factors must be taken into account. Absorbed dose = The amount of energy absorbed from a radiation exposure Unit: Gray (Gy) = 1 joule absorbed/kg This measurement can be made for different types of radiation (alpha, beta, gamma/X-rays, etc.) that vary in the degree of ionization that they cause. To assess their detrimental effect on biological tissues, it is necessary to adjust the absorbed dose by a radiation weighting factor (WR) specific to the type of radiation. Equivalent dose = the absorbed dose multiplied by WR Unit: Sievert (Sv) WR value: X-rays = 1 Alpha particles = 20 (therefore for X-rays the equivalent dose is equal to the absorbed dose) To compare the potential harm caused by different radiographic examinations, it is necessary to make a further adjustment that takes account of the radiosensitivity of the tissues being irradiated. A list of weighting factors has been calculated for different organs of the body. For a particular examination the equivalent dose reaching each of these organs can be measured experimentally and this value is multiplied by the weighting factor for that organ. Adding up the resulting figures for all the tissues involved gives a value that represents the risk of causing biological harm from that procedure. It allows the risk from different examinations in different parts of the body to be compared. http://dentalebooks.com 180 • C L I N I C A L D E N T I S T RY Effective dose = the equivalent dose multiplied by the tissue weighting factor (W T ) Unit: Sievert (Sv) When referring to the dose for a particular procedure it is usually the effective dose that is quoted. Doses for common radiographic examinations and their comparative risk Although it would be desirable to be able to quote one figure as the effective dose for a particular procedure, this is not possible due to the wide variation that occurs depending on the type of equipment and film/sensors that are used. When considering cross-sectional imaging, the field of view and resolution that is chosen will influence the dose. Table 8.1 shows the range of values for some common radiographic examinations. The lower figures represent imaging carried out using modern techniques and equipment. Table 8.2 gives an estimate of the risk from dental radiography associated with some of the lower effective doses in comparison to our exposure to natural background radiation (2.23 mSv/year). However, another factor, which must be taken into account, is the age of the patient. The figures in Table 8.1 are average figures for the population, but the risk to younger patients is higher for the same amount of radiation received and for older patients it is lower. Table 8.3 lists the multiplication factors to adjust the risk for different age groups. TABLE 8.1 Effective doses for traditional dental radiography, CBCT and CT* X-ray examination Effective dose (µSv) Intraoral radiograph 0.7–38 Panoramic 2.7–38 Lateral cephalomeric radiograph 2.2–14 CBCT (small FOV ≤5 cm) 0.015 CBCT (medium FOV >5 but ≤10 cm) 18–674 CBCT (large FOV >10 but ≤15 cm) 60–510.6 CBCT (extended FOV > 15 cm) 30–1025 CT scan (mandible) 250–1410 CT (mandible and maxilla) 430–860 FOV = Field Of View (height of cylindrical volume or spherical diameter of volume) *Faculty of General Dental Practitioners (UK), 2013. http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 181 TABLE 8.2 An estimate of the risk of developing a fatal malignancy associated with common radiographic examinations and the amount of natural background radiation associated with an equivalent risk X-ray examination Risk Equivalent background radiation A bitewing or periapical taken using modern equipment and techniques 1 : 10 000 000 8 hours A panoramic 1 : 1 000 000 3.2 days Upper standard occlusal 1 : 2 500 000 8 days Lateral cephalometric view 1 : 5 000 000 16 days Dento-alveolar cone beam CT 1 : 2 000 000 to 1 : 30 000 1.6–109 days Craniofacial cone beam CT 1 : 670 000 to 1 : 18 200 5–180 days CT mandible and maxilla 1 : 80 000 to 1 : 14 300 41–229 days TABLE 8.3 Risk in relation to age* Age group (years) Multiplication factor for risk <10 ×3 10–20 ×2 20–30 ×1.5 30–50 ×0.5 50–80 ×0.3 80+ negligible risk Multiplication factor at 30 years = 1. *Faculty of General Dental Practitioners (UK), 2004. The biological effects of radiation Radiation can have two effects on the body: deterministic and stochastic. Deterministic effects Deterministic effects are those which are certain to happen if a high enough dose is given. Their severity is dose-dependent and it is believed that there is a dose threshold below which no effect will occur. Following high radiation doses, such as in nuclear accidents, deterministic effects include reddening of the skin and the development of cataracts. http://dentalebooks.com 182 • C L I N I C A L D E N T I S T RY However, if modern radiation safety rules are followed, none of these effects will result from dental radiography. Deterministic effects: severity α dose Stochastic effects Stochastic effects are those that may happen, the chance of their occurrence being proportional to the dose. Stochastic effects include the induction of malignant tumours and, if there is irradiation of the reproductive organs, the induction of mutations, which may lead to congenital abnormalities. The induction of neoplastic disease is the main risk of radiography. Stochastic effects: probability α dose Dose limitation in dental radiography The principles of patient dose limitation can be summarized by two terms: justification and optimization. Justification The prescription of radiographs must, in every case, be of some positive benefit to the patient and influence their treatment. The clinician should be sure that the information required is not already available on any existing images, e.g. root morphology prior to an extraction. Optimization Where the decision has been made to request a radiograph, the dose must be kept As Low As Reasonably Practicable (ALARP). This can be achieved by using appropriate equipment, good technique and by having a quality control programme in place to ensure that the images are consistently of diagnostic quality. Equipment X-ray generator. Preferably constant potential rather than AC. Voltage. 60–70 kV. FSD. Minimum focus to skin distance of 200 mm for intraoral radiography. Film holders. For bitewing and periapical radiography. Collimation. Rectangular collimation for intraoral images. For panoramic radiography the use of sectional views, where possible, limited to the area of interest and a reduced field of view for children. http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 183 TABLE 8.4 Equipment factors and dose* Equipment factors Multiplication factor for estimating the effective dose Digital system (phosphor plate) ×0.25–0.75 Digital system (CCD) ×0.5 Rectangular collimation ×0.5 F-speed film ×0.8 ’DC’ constant potential ×0.8 ’Short cone’ (10 cm fsd) ×1.5 50 kV set ×2 D-speed film ×2 *Faculty of General Dental Practitioners (UK), 2004. Image capture. Fast film: E or F speed for intraoral views. Rare earth intensifying screens for extraoral views. Digital radiography. Technique Radiography should only be undertaken by staff who have been appropriately trained. The effect on patient dose of different equipment factors is summarized in Table 8.4. Quality assurance (QA) Inspection of X-ray equipment. Critical examination and acceptance test after installation; routine tests at regular intervals, not exceeding 3 years and following relocation, repair or modification; servicing as directed by the manufacturer. Checks on darkroom, films and processing. Processing conditions and changing of chemicals; light-tightness of darkroom; performance of safe lights; film storage and expiry dates. Digital systems. Check for sensor/phosphor plate damage; use test pattern to check monitors. Programme of staff training. Rigorous and on-going. Image quality. Subjective assessment of each film using the threepoint quality rating (Table 8.5) and quality targets recommended by the National Radiological Protection Board/Royal College of Radiologists (National Radiological Protection Board, 1994; Table 8.6); analysis of reject images on a regular basis to identify faults and to allow changes to be implemented to prevent their recurrence. Audit. Records should be kept of the QA procedures and an audit of them carried out at least every 12 months. http://dentalebooks.com 184 • C L I N I C A L D E N T I S T RY TABLE 8.5 Subjective quality rating of radiographs* Rating Quality Basis 1 Excellent No errors of patient preparation, exposure, positioning, processing or film handling 2 Diagnostically acceptable Some errors of patient preparation, exposure, positioning, processing or film handling, but do not detract from the diagnostic utility of the radiograph 3 Unacceptable Errors of patient preparation, exposure, positioning, processing or film handling which render the radiograph diagnostically unacceptable *National Radiological Protection Board, 1994. TABLE 8.6 Minimum targets for radiographic quality* Rating Percentage of radiographs taken 1 Not less than 70% 2 Not greater than 20% 3 Not greater than 10% *National Radiological Protection Board, 1994. Lead aprons and radiography in pregnancy There is no justification for the routine use of lead aprons for patients in dental radiography, and for panoramic radiography their use is positively discouraged as the apron may interfere with the movement of the machine. A thyroid collar is of value if the gland is in the primary beam, as occurs in an upper standard occlusal, but otherwise, if rectangular collimation and the paralleling technique are used, thyroid shielding is unnecessary. The Ionizing Radiation (Medical Exposure) Regulations 2000 prohibit the carrying out of a medical exposure on a female of childbearing age without enquiry as to whether she is pregnant, if this is relevant. In dentistry this enquiry should not normally be necessary as the only view where the primary beam is directed towards the pelvic area is the vertex occlusal – a projection rarely used now and difficult to justify for a pregnant woman. Although some practitioners avoid radiography in patients known to be pregnant, essentially for psychological reasons, a more pragmatic approach is to explain to the patient that for the majority of dental projections, the pelvic area is not irradiated directly and that the dose received by the foetus http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 185 from scattered radiation is so small that the associated risk can be regarded as negligible. Radiography should be limited to those films necessary for assessing an acute problem; any non-urgent radiography should be delayed until after the birth. If these guidelines are followed it is unnecessary to use a lead apron even during pregnancy, although its use may be of some psychological benefit. Ionizing radiation regulations Dentists who use X-ray equipment in the UK must comply with the Ionizing Radiations 1999 and the Ionizing Radiation (Medical Exposure) Regulations 2000. Guidance on the implementation of these regulations are contained in the Guidance Notes (Department of Health, 2001). The important points are as follows: Notification. The employer (practice principal) must notify the Health and Safety Executive before work with ionizing radiation is carried out for the first time. Risk assessment. This must be carried out by the employer to assess the risk to any employee from the use of radiographic equipment and to identify precautionary measures that may be required. Radiation Protection Adviser (RPA). Dentists must formally appoint an RPA, a physicist, who will advise on compliance with the regulations. A controlled area. This must be designated around an X-ray unit in consultation with the RPA. The standard approach is: within the primary beam until sufficiently attenuated by distance or shielding; within 1.5 m of the X-ray tube or the patient’s head. However, the Guidance Notes (Department of Health, 2001) advise that the operator stands at a distance of at least 2 m. Local rules. These must be provided for any controlled area and a Radiation Protection Supervisor (RPS) must be appointed to ensure compliance with the regulations and the local rules. The RPS will usually be a dentist or a suitably trained person. Personnel. Three categories of staff are designated: the referrer (requests the radiograph); the practitioner (justifies the exposure – a radiologist in a hospital) and the operator (operates the machine). In a dental practice all three jobs will probably be carried out by the dentist unless there is a dental nurse with radiographic training who may act as the operator. Training. The practitioner and operator must have received adequate training and must undertake continuing education. Justification and optimization. No person shall carry out an exposure unless it has been justified by the practitioner as being of net http://dentalebooks.com 186 • C L I N I C A L D E N T I S T RY benefit to the patient. Once the decision has been made to take a radiograph, the dose must be kept ALARP. To aid optimization each practice should set Diagnostic Reference Levels (DRLs) for each type of projection. These are doses for each type of examination that should not be exceeded. The Selection Criteria For Dental Radiography (Faculty of General Dental Practitioners, 2013), give details of the DRLs which are currently suggested for dental radiography. Quality assurance (QA). Dental practices must have a QA programme for all procedures and this must be audited. X-ray equipment must be serviced regularly and radiation safety tests carried out at least every 3 years. Radiographic technique Intraoral views Periapical radiography Paralleling technique. A film holder is used that aligns the film/ sensor parallel to the tooth and also has a guide (beam aiming device) to position the beam at 90° to the film/sensor. This projection gives the most accurate and reproducible image of the tooth and periapical tissues. Bisecting angle technique. The film/sensor is placed against the back of the tooth and the X-ray tube is aligned at 90° to the plane halfway between the tooth and the film/sensor. The patient used to be asked to hold the film/sensor in place with their finger, but it is now advisable to use a film holder to avoid irradiating the hand. The advantage of the bisecting angle technique is that where there is a limited amount of space, such as in patients with a shallow palate, this technique can be easier to perform than the paralleling technique. The disadvantage is that the technique is prone to inaccuracy due to misjudgement of the vertical angulation of the tube. This leads to elongation or foreshortening of the image. Bitewing This projection is used to image the crowns of the teeth in both arches and usually allows the alveolar bone levels to be assessed. The technique originally involved the patient biting down on a paper tab stuck on to the film packet (from which the name derives), but it is now advisable to use a film holder to facilitate more accurate positioning. The X-ray tube is positioned at 90° to the dental arch in the horizontal plane so that the beam passes between the contact points. In the vertical plane the beam is aimed down at 5–7° to the horizontal to http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 187 avoid overlapping the cusp tips, which are inclined because of the curve of Monson. Occlusal radiographs Upper standard occlusal. The film/sensor is placed centrally between the two dental arches with the beam aligned through the bridge of the nose with a 60° downward angulation. This view is used to detect pathology and buried or supernumerary teeth in the palate. Information about the position of a buried tooth relative to the dental arch can be gained using the principle of parallax by combining this view with another taken at different horizontal or vertical angle. Upper true (vertex) occlusal. The film/sensor is placed centrally between the two dental arches with the X-ray tube positioned at the vertex of the skull pointing down the long axis of the upper teeth. This view clearly shows the position of a buried or supernumerary tooth relative to the dental arch, but the projection results in a relatively high dose of radiation to the lens of the eye and consequently is no longer recommended. Upper oblique occlusal. This view is similar to the Upper standard occlusal, but with the film/sensor and the X-ray tube positioned over to one side of the arch to image a more posterior part of the dentition. The X-ray beam is angled down at 65–70°. This view shows the posterior teeth, the surrounding bone and the antral floor. It is useful for imaging pathology, dentoalveolar fractures and roots displaced into the antrum. Lower standard occlusal. The film/sensor is placed centrally between the two dental arches with the beam aligned with a 45° upward angulation through the chin. This view shows the lower incisor teeth and surrounding bone and is useful for demonstrating pathology that extends beyond the limits of a periapical image. Lower true occlusal. The film/sensor is placed centrally between the two dental arches with the beam aligned at 90° to it. This image is used to assess mandibular fractures of the anterior mandible and the buccolingual expansion of lesions such as cysts and tumours. It is also used to identify calculi in the submandibular ducts. Lower oblique occlusal. The film/sensor packet is placed between the dental arches, positioned over to the side under investigation with the X-ray beam angled up from below and behind the angle of the mandible. This view is usually used in conjunction with the lower true occlusal for the detection of salivary calculi. It will identify stones in the posterior part of the submandibular duct and in the gland. It can also be used to assess the buccolingual expansion of lesions in the posterior part of the body of the mandible. http://dentalebooks.com 188 • C L I N I C A L D E N T I S T RY Extraoral projections Panoramic • • • • Also referred to as a Dental Panoramic Tomogram (DPT) or by a trade name, orthopantomogram (OPT/OPG). An image of the dental arches is produced by the technique of tomography that involves rotating the X-ray tube and film/sensor producing blurring of the structures on either side of the centre of rotation. In dental panoramic tomography a horseshoe-shaped in-focus plane (focal trough) is produced by moving the centre of rotation during the exposure. Care must be taken in patient positioning to ensure that the teeth lie within the trough. A panoramic image is magnified by 1.2–1.3 times. Failure to position the patient correctly results in changes in the horizontal magnification. Patient too far into the machine → narrow anterior teeth. Patient too far out of the machine → wide anterior teeth. Patient rotated → posterior teeth and rami are wider on one side and narrower on the other. The anatomical features observable on a panoramic radiograph are illustrated in Figure 8.3. Oblique lateral Used to image the posterior maxilla and mandible but largely superseded by the panoramic. The patient is positioned with head tilted against the film/sensor. The beam is then aligned at 90° to it from under the angle of the mandible on the contralateral side. Posteroanterior (PA) jaw Used to assess fractures and pathology in the posterior mandible and condyles. The patient is positioned with nose and forehead against film/sensor. The beam is aimed horizontally from behind the head. Reverse Towne’s projection Used to assess the condyles. The patient is positioned in a similar way to a PA but with the mouth open to bring the condyles out of the fossae. The beam is then aimed upwards from behind the head from 30° below the horizontal. Occipitomental (OM) Used to assess the sinuses and fractures of the maxilla, zygomatic complex, orbits and coronoid process. The patient is positioned facing the film/sensor with head tilted back at 45° in the ‘nose–chin’ position, the X-ray tube aligned behind the head and angled down at 0–45° to the horizontal. http://dentalebooks.com http://dentalebooks.com H C F A G D B E I 4 3 1 2 23 5 6 24 78 9 27 11 10 16 25 22 19 20 21 26 Soft tissue anatomy and air shadows: F. Outline of epiglottis A. Outline of adenoids G. Outline of anterior wall of pharynx B. Outline of soft palate H. Outline of posterior wall of pharynx C. Outline of ear lobe I. Air in nasal cavity D. Air in nasopharynx E. Outline of dorsum of tongue 15 14 12 17 18 13 • Figure 8.3 Anatomical features on a panoramic radiograph. Bony anatomy: 1. Nasal septum 2. Nasal cavity 3. Inferior concha 4. Anterior nasal spine 5. Infra-orbital rim 6. Infra-orbital canal 7. Floor of nose/hard palate 8. Zygomatic buttress 9. Zygomatic arch 10. Pterygo-maxillary fissure 11. Lateral pterygoid plate 12. Articular eminence 13. External auditory meatus 14. Styloid process 15. Mandibular condyle 16. Sigmoid notch 17. Cervical vertebrae 18. Foramen transversarium 19. External oblique ridge 20. Internal oblique ridge 21. Mandibular foramen 22. Inferior alveolar canal 23. Mental foramen 24. Bony cortex of inferior border of mandible 25. Antegonial notch 26. Hyoid bone 27. Coronoid process D ental and m a x ill o f acial radi o l o g y 189 190 • C L I N I C A L D E N T I S T RY Submentovertex (SMV) Used to assess fractures of the zygomatic arches and pathology in the palate and skull base. The patient is positioned with the head tilted back as far as possible against the film/sensor. The beam is then aimed upwards from under the chin. Contraindicated if there is any possibility of a fracture of the cervical spine. Lateral cephalometric view Taken for orthodontic purposes using a cephalostat to hold the patient in a standardized and reproducible position. The patient is positioned with their teeth in occlusion and with a natural head position or with the Frankfurt plane horizontal. The film/sensor is positioned parallel to the sagittal plane and the beam is aligned at 90° to it. For the majority of cephalometric analyses the cephalometric view can be coned down to show just the facial skeleton, auditory canal and the anterior cranial base. Advanced imaging techniques Computed tomography (CT) An X-ray tube passes around the body, usually in a spiral pattern, producing a flat ‘fan-shaped’ beam which is then picked up by a series of detectors which measure the attenuation (absorption) of the beam at each point of the rotation. A computer can then assign a value (Hounsfield number) to the density of each area within the scan. Using this data the computer can then reconstruct slices through the body at any desired interval and in any plane. CT shows both soft tissue and bone but does not demonstrate soft-tissue lesions as well as does Magnetic Resonance Imaging (MRI). CT is particularly useful for assessing serious mid-facial trauma or disease involving bone. Cone beam computed tomography (CBCT) An X-ray tube producing a cone-shaped beam passes around the area of interest in a single 360° or 180° rotation collecting information from a predefined volume of tissue. CBCT scanning shows hard tissue at a higher resolution and with a lower dose than conventional CT, but has poorer soft tissue visualization. The machines allow a choice of fields of view, from large volumes showing the whole maxillofacial region to small volumes showing just 2–3 teeth. Magnetic resonance imaging (MRI) This does not use ionizing radiation, but instead involves placing the patient into a strong magnetic field and then applying pulses of radio waves. The frequency of these waves is chosen specifically so that the abundant hydrogen protons in body fluid take up energy from the http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 191 signal. The protons then emit a radio signal, which is picked up and processed by a computer. Several different images of each slice through the patient are produced. The main ones are T1, T2 and proton-density weighted images, each reflecting different characteristics of the tissue. T1 shows the anatomy well, whereas pathology is usually demonstrated better on T2. MRI gives good soft-tissue detail and is excellent for tumour staging and for the assessment of intra­ cranial disease. It can also be used to image the TMJ as it allows direct imaging of the disc. MRI is not good for imaging bone as this tends to appear as a signal void due to the absence of fluid. The advantage of MRI is that it does not involve ionizing radiation; however, it is contraindicated in patients with ferromagnetic surgical clips, pacemakers and cochlear implants. There is no evidence to suggest MRI scans pose a risk during pregnancy. However, as a precaution they are not usually recommended, particularly in the first 3 months. Ultrasonography (US) This non-invasive technique involves scanning the patient with a transducer that emits high-frequency sound waves (1–15 MHz) and then detects the waves reflected from various interfaces within the tissue. The time taken for the waves to be reflected back allows the machine to calculate the depth of the structures that reflected them and from this a picture is created. Ultrasound is excellent for the assessment of superficial soft-tissue structures such as salivary glands, lymph nodes and the thyroid. Fine-needle aspiration under ultrasound guidance can be used to provide further diagnostic information and Doppler imaging can be used to assess vascularity. Diagnostic ultrasound is considered to be a very safe technique, with no contraindications or adverse effects. Radiographic contrast techniques in the head and neck Radiographic contrast agents are radio-opaque substances containing iodine that when introduced into the body artificially alter the contrast. Adverse reactions to these agents are rare, but patients should always be asked if they have ever had an allergic reaction to iodine. Sialography This involves the introduction of radiographic contrast into the ductal system of the parotid or submandibular glands. Indications. Symptoms suggestive of ductal obstruction; suspected Sjögren’s syndrome. Contraindications. Acute salivary gland infection; suspected mass lesions – sialography can be misleading; other techniques are more appropriate. http://dentalebooks.com 192 • C L I N I C A L D E N T I S T RY Angiography This involves the injection of radiographic contrast into the vascular system, usually via a catheter introduced into the femoral artery. Under fluoroscopic control (real-time imaging) the catheter can be passed into a specific artery such as the external carotid to allow selective catheterization of its branches. This technique may be used to investigate haemangiomas, arteriovenous malformations and suspected intracranial bleeds. TMJ arthrography This involves the introduction of radiographic contrast into the joint space, usually the inferior compartment, to determine the disc position and to detect disc perforations and adhesions. This technique can give a truly dynamic assessment of disc position but it is uncomfortable for the patient and has largely been replaced by MRI. Radionuclide imaging This involves the injection of a radioactive agent into the bloodstream that emits gamma rays, which can be detected by a gamma camera. Technetium-99m is the most commonly used isotope, but other substances can be attached to it so that the isotope is concentrated in a particular tissue – e.g. methylene diphosphonate (MDP) for bone scans. Radionuclide imaging is useful for assessing the function or activity of a tissue, but the disadvantages are the relatively high dose, poor resolution and limited disease specificity. Indications. Detection of bony metastases and bony invasion by tumours; assessment of bone grafts; assessment of growth in condylar hyperplasia; investigation of salivary gland function; assessment of thyroid function. Guidelines for the prescription of radiographs Radiographs should be requested only after taking the patient’s medical history and completing a full clinical examination; in this way they are likely to contribute to a clinical diagnosis and management. The use of panoramic radiographs to routinely screen new patients cannot be justified in view of the low diagnostic yield and the minimal impact it has on the management of the vast majority of patients. A panoramic radiograph may be of value for a patient with a very heavily restored or neglected dentition, but for most patients bitewings (which more accurately record early caries and periodontal bone loss) are more appropriate. When requesting a radiograph, the operator should always ask the question ‘Will this radiograph affect this patient’s management or prognosis?’ http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 193 Patients in pain (Table 8.7) Evidence-based guidelines have been produced by the Faculty of General Dental Practitioners (FGDP) (Faculty of General Dental Practitioners, 2013). Some guidelines based on this work are listed here, but for more detail the reader is advised to refer to the original text. TABLE 8.7 Radiographs in the investigation of pain Symptom Appropriate imaging Dental pain with hot and/or cold, but not tender to pressure Periapical of tooth (or teeth) under suspicion or a bitewing of affected side if pain difficult to localize Tooth tender to percussion Periapical radiograph Dental abscess and/or facial swelling Periapical view or sectional panoramic radiograph Pericoronitis See third molar assessment TMJ pain Specific TMJ radiography for these patients rarely reveals anything that affects the management of the condition. A panoramic film is sometimes helpful to exclude concurrent dental disease should there be any confusion following the clinical examination. A good view of the condyles can be obtained by asking for a panoramic radiograph with the mouth open and the jaw protruded If the patient fails to respond to conservative treatment, the most helpful investigation is MRI If the clinical examination suggests the possibility of condylar hyperplasia, then a panoramic radiograph or CBCT is indicated together with a bone scan Atypical facial pain Suggest a panoramic radiograph of the affected side. An MRI scan may be indicated if there is no response to medical treatment Trigeminal neuralgia An MRI scan is indicated to check for a neoplasm along the course of the nerve or for evidence of multiple sclerosis (demyelination) in younger patients (under 40) Sinusitis Exclude dental disease using appropriate views Commence medical treatment and if no response a limited CBCT/CT investigation may be requested if thought appropriate by an ENT specialist Occipitomental (OM) views are not routinely indicated as a normal OM view does not exclude the presence of potentially significant pathology, particularly in the frontal, ethmoidal and sphenoidal sinuses http://dentalebooks.com 194 • C L I N I C A L D E N T I S T RY TABLE 8.8 Radiographs in the diagnosis of dental caries Caries risk Frequency of radiograph High Posterior bitewings at 6-month intervals until no new or active lesions are apparent and the individual has entered another risk category Moderate Annual posterior bitewings at intervals unless risk status alters Low Primary dentition: intervals of 12–18 months Permanent dentition: 2-year intervals, but more extended recall intervals may be employed if there is explicit evidence of continuing low caries risk Diagnosis of caries The FGDP recommend that the taking of ‘routine’ radiographs based solely on time elapsed since last examination is not supportable. A patient should be exposed to ionizing radiation only after a thorough clinical examination, which should include an assessment of caries risk as high, medium or low (Table 8.8). The frequency of radiographic examinations should be based on this assessment, but must be kept under review as individuals move in and out of caries risk categories with time. Periodontal assessment The FGDP found no clear evidence in the literature regarding the frequency of radiographs for periodontal assessment. It was concluded, however, that bitewing radiographs should be used where possible as they offer the optimal geometry and fine detail of intraoral radiography and, when they are already indicated for caries assessment, they provide information about bone levels without any additional radiation dose. Early loss of bone height can be captured on horizontal bitewings but in more severe cases vertical bitewings can be used (see Table 8.9). Oral surgery Radiography before routine extractions Opinion is divided as to whether a radiograph is always required before an extraction, but in most cases an image to assess the root morphology, associated pathology and any neighbouring structures is advisable. However, from a radiation protection point of view, each exposure must be justified on an individual basis. If an image already exists that shows the root pattern, further radiography may be unnecessary (see Table 8.10). http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 195 TABLE 8.9 Imaging in the assessment of periodontal disease Lesion Radiograph Uniform pocketing <6 mm and little or no recession Horizontal bitewings Pocketing of 6 mm or more Vertical bitewings supplemented if necessary by intraoral periapical views, using the paralleling technique Irregular pocketing Bitewing radiographs (horizontal or vertical depending on pocket depth), supplemented if necessary by periapical radiographs taken using the paralleling technique Where there are concurrent problems for which radiography is indicated (e.g. symptomatic third molars, multiple existing crowns/ heavily restored teeth and/or multiple endodontically treated teeth in a patient new to the practice) A panoramic radiograph may offer a dose advantage over a large number of intraoral radiographs. However, in view of the limitations in fine detail on panoramic radiographs, supplementary intraoral radiographs may be necessary for selected sites Periodontal/endodontic lesion A periapical radiograph taken using the paralleling technique TABLE 8.10 Imaging prior to routine extractions Extraction Radiograph A broken-down tooth which may require a surgical procedure When there is a history of difficult extractions When there is a history of bone disease When the tooth is a lone standing upper molar Periapical radiograph Multiple carious teeth in several quadrants to be extracted Extractions under general anaesthesia Panoramic radiograph Surgical procedures See Table 8.11. Third molar assessment See Table 8.12. Trauma See Table 8.13. http://dentalebooks.com 196 • C L I N I C A L D E N T I S T RY TABLE 8.11 Imaging prior to minor surgery Procedure Radiograph Removal of root fragments Small cysts Apicectomies Periapical radiograph Oroantral fistula/root displaced into antrum Sectional panoramic radiograph, upper oblique occlusal or CBCT TABLE 8.12 Imaging in third molar assessment Symptoms Examination Unilateral symptoms Sectional panoramic radiograph of symptomatic side A full panoramic is justified to enable the asymptomatic contralateral side to be assessed if a general anaesthetic is required +/− CBCT if this shows a close relationship with the ID canal Bilateral symptoms Full panoramic +/− CBCT (as above) Radiography is only justified prior to planned surgical removal; routine radiography of unerupted or asymptomatic partially erupted third molars is not recommended. TABLE 8.13 Imaging in the assessment of facial bone fractures Injury Examination Suspected dento-alveolar fracture A combination of periapical views at different angles (paralleling and bisecting angle) or a periapical and an upper oblique occlusal are most likely to reveal the presence of a root or alveolar bone fracture Suspected mandibular fracture Panoramic and posteroanterior jaw view taken with the mouth open to show the mandibular condyles more clearly Suspected zygomatic fracture Occipitomental 10° ± 30° views supplemented by a submentovertex view where the fracture is found to be limited to the zygomatic arch (this view is contraindicated if the patient cannot safely extend their neck, e.g. possible cervical spine fracture) Suspected Le Fort fracture Occipitomental 10° ± 30°and lateral skull views initially, followed by CBCT/CT scanning http://dentalebooks.com D ental and m a x ill o f acial radi o l o g y • 197 TABLE 8.14 Imaging in the assessment of salivary gland disease Problem Examination Symptoms of obstruction Plain films may reveal radio-opaque calculi. Submandibular gland – lower true occlusal, lower oblique occlusal and half panoramic radiographs. Parotid – anteroposterior soft tissue view ± periapical film of duct orifice Sialography – after acute symptoms have settled. May reveal radiolucent calculi or strictures and it can also be therapeutic Suspected autoimmune salivary gland disease – Sjögren’s syndrome Ultrasound scan +/− sialography A palpable lump in a salivary gland Ultrasound scan followed by MRI TABLE 8.15 Principles of describing a lesion Characteristic Details Number Single or multiple Density Radiolucent, mixed or radio-opaque Site Anatomical position and whether it appears to be related to a particular structure (e.g. a buried tooth or the ID canal) If you have only one radiograph be aware of the possibility of superimposition, particularly if describing a radio-opaque lesion. Another view at right angles may be required to describe accurately the position of a lesion Size Take account of any radiographic magnification, or describe extension relative to anatomical structures Internal architecture Unilocular/multilocular, calcifications, etc. Borders Well defined or poorly defined Affect on surrounding structures Resorption of roots, displacement of ID nerve or expansion of the bone Changes with time If previous films are available Salivary gland disease See Table 8.14. Interpretation of radiographs The features to consider when describing the radiographic appearance of a lesion are listed in Table 8.15. http://dentalebooks.com http://dentalebooks.com Central haemangioma Arteriovenous malformation Neurofibroma Keratocyst Ameloblastoma Lateral periodontal cyst Normal follicular space Periodontal disease Roots or buried teeth *May develop internal calcification as they mature. Osteosarcoma or osteogenic metastases Paget disease Fibrous dysplasia Osteomyelitis Sclerosing osteitis or dense bone island Vascular calcification Salivary calculi Calcified lymph nodes or tonsils Osteoma Odontomes Cemental dysplasia Eosinophilic granuloma Secondary malignancy Primary malignancy Osteoradionecrosis Osteomyelitis Radio-opaque lesions (well defined) Neurofibroma Calcifying odontogenic cyst* Calcifying epithelial odontogenic tumour* Adenomatoid odontogenic tumour* Ameloblastic fibroma Developing odontome Keratocyst Ameloblastoma Paradental cyst Dentigerous cyst Radiolucent lesions with indistinct borders Neurilemmoma Solitary bone cyst Cherubism Aneurysmal bone cyst Nasopalatine cyst Stafne idiopathic bone cavity Giant cell granuloma Myxoma Residual cyst Giant cell granuloma Keratocyst Ameloblastoma Apical granuloma Pericoronal radiolucent lesions • Radicular cyst Well-defined multilocular radiolucent lesions Well-defined unilocular radiolucent lesions TABLE 8.16 Radiological differential diagnosis 198 C L I N I C A L D E N T I S T RY D ental and m a x ill o f acial radi o l o g y • 199 Differential diagnosis of radiographic lesions The differential diagnosis of lesions observed on a radiograph are described in Table 8.16. References Department of Health, 2001. Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment. HMSO, London. Faculty of General Dental Practitioners (UK), 2004. Selection criteria for dental radiography, second ed. Faculty of General Dental Practitioners (UK), London. Faculty of General Dental Practitioners (UK), 2013. Selection criteria for dental radiography, third ed. Faculty of General Dental Practitioners (UK), London. National Radiological Protection Board, 1994. Guidelines on Radiology Standards for Primary Dental Care. Doc. NRPB, 5, No 3. http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Pain and anxiety management Local anaesthesia (LA) 201 Conscious sedation (CS) 210 General anaesthesia (GA) 218 Cognitive behavioural therapy (CBT) 220 9 Hypnotherapy 221 Acupuncture 221 Successful management of the patient’s pain and anxiety is central to the practice of dentistry. The range of pharmacological and nonpharmacological techniques at the disposal of the dental clinician, all of which rely to some extent on the behaviour management skills of the dental team include: • • • • • • • Local anaesthesia (also termed local analgesia) (LA) Conscious sedation (CS) General anaesthesia (GA) Cognitive behavioural therapy (CBT) Hypnotherapy Acupuncture TENS (Transcutaneous Electrical Nerve Stimulation). Local anaesthesia (LA) Local anaesthesia (or local analgesia) is the mainstay of pain management in dental practice. Local anaesthetics block nerve conduction reversibly by inhibiting the influx of sodium ions into nerve fibres, so allowing procedures to be performed while the patient is pain-free. In dentistry, the most commonly used local anaesthetics are as shown in Box 9.1. LA is administered by a range of techniques: • • • • • topical application infiltration injection regional nerve block injection intraligamental/intraosseous injection intrapapillary injection. These techniques are often used in combination, the best combination being dependent on factors such as anatomical site, nature of dental treatment, patient compliance and patient medical history. http://dentalebooks.com 202 • C L I N I C A L D E N T I S T RY Box 9.1 Common dental LAs 2% lidocaine (lignocaine) with 1 : 80 000 adrenaline 4% articaine with 1 : 100 000 adrenaline 4% articaine with 1 : 200 000 adrenaline 3% prilocaine with felypressin 0.03 IU 3% mepivicaine 0.5% bupivicaine with 1 : 200 000 adrenaline Hydrophilic Substituted amino group Lipophilic Aromatic head N Figure 9.1 Basic structure of local anaesthetic. What are the general properties of local analgesics? An LA molecule has three main components: a lipophilic aromatic ring, an ester or amide chain and a terminal amine (Figure 9.1). The aromatic ring is responsible for the lipid solubility of the LA, required to enable the solution to diffuse into the nerve sheath. The terminal amine makes the LA molecule water soluble on injection and lipid soluble at physiological pH (the solution needs to be lipid soluble to diffuse into the nerve sheaths). Local anaesthetics with an ester chain, e.g. benzocaine are hydrolysed by plasma esterases. Those with an amide chain, e.g. lidocaine are metabolized by liver enzymes. Articaine has both an amide chain and an ester side chain which is hydrolysed to an inactive metabolite which is then partly metabolized in the kidney. Why vasoconstrictors? Plain local analgesics are vasodilators so, without the addition of a vasoconstrictor to the LA solution, the following unwanted effects could occur: • increased absorption of the LA into the systemic circulation, so increasing the risk of toxicity http://dentalebooks.com Pain and an x iety m ana g e m ent • • • 203 decreased depth and duration of LA due to diffusion of solution away from the operating site increased bleeding at the operating site due to increased blood perfusion. The majority of LA solutions do contain a vasoconstrictor, usually adrenaline or felypressin. Adrenaline (epinephrine) should be used with caution in patients with cardiac disease (i.e. limiting dose at each treatment visit to 1–2 cartridges [a cartridge typically contains around 2 ml of solution]). Felypressin is an analogue of vasopressin and therefore best avoided in pregnancy. What dose of local analgesic is ‘safe’? Safe maximum doses are designed to prevent toxicity (Table 9.1). TABLE 9.1 Safe maximum doses of local anaesthetic Maximum safe dose (mg/kg) Approximate number of cartridges (2–2.2 ml) in a healthy adult of normal weight 2% lidocaine with 1 : 80 000 adrenaline 4.4 mg/kg 6–8 3% prilocaine with felypressin 6.0 mg/kg 5–6 4% articaine with 1 : 000 000/1 : 200 000 adrenaline 7.0 mg/kg 6 LA Which LA techniques and where? Topical Topical LA may have both psychological and pharmacological effects. It tends to work best prior to infiltration injections and least well prior to inferior dental block injections. The most commonly used intraoral topical LA is 20% benzocaine paste, applied to the injection site for 2–5 minutes. Benzocaine is an ester LA and is, however, prone to allergies. EMLA cream contains lidocaine and prilocaine and Ametop contains amethocaine (also known as tetracaine). These products are not normally used intraorally, but for skin anaesthesia, e.g. before inserting an intravenous cannula. Infiltration LA injections are best given after aspiration (to avoid injecting LA into a blood vessel), and also slowly – to avoid pain. Infiltration http://dentalebooks.com 204 • C L I N I C A L D E N T I S T RY delivers LA solution at or near the apex of the tooth which then diffuses through cortical bone to affect the periapical nerves and those serving the periapical ligament. Bone porosity is needed to allow this diffusion to occur, so it may be less effective where the cortical plate is thicker (mandibular molars and premolars). Palatal infiltration can be uncomfortable due to low tissue compliance. This can be overcome by starting palatal anaesthesia from the buccal aspect with an interpapillary injection, or using very slow delivery with a ‘wand’ where the LA flow rate is computer-regulated. Infiltration technique There are two distinct stages in the procedure: 1. Insertion of needle This requires firm stretching (with the finger or thumb) of the sulcus such that the mucosa becomes taut, and hence allows less discomfort on needle penetration. Only 2–3 mm of needle is generally inserted and the angulation of the syringe is approximately parallel to the long axis of the tooth. 2. Deposition of the solution Before depressing the syringe plunger, it is prudent, even with infiltration, to aspirate. The solution should be introduced slowly to avoid tissue damage, which may be considerable given the very narrow gauge of dental needles. Regional nerve block In a nerve block, the LA solution is deposited around a nerve trunk, causing anaesthesia to the tissues within the distribution of the nerve peripheral to the point of administration. The most common nerve blocks in dentistry are: Inferior dental block (IDB) – all lower teeth on the side of the block. Mental nerve block – lower first premolar to central incisor on the side of the block. Other blocks include infraorbital, nasopalatine, posterior superior alveolar and greater palatine. The most commonly given by far is the inferior dental block injection. Tissues anaesthetized will include tissues served by the lingual nerve in addition to tissues supplied by the inferior dental nerve. ID nerve block Tissues anaesthetized ID nerve. Mandibular teeth – pulps and periodontium; bone of mandible in toothbearing area; buccal gingivae from premolars to midline; lower lip and chin; cheek variably adjacent to premolars/ canine. http://dentalebooks.com Pain and an x iety m ana g e m ent • 205 Lingual nerve. Anterior two-thirds tongue; floor of mouth; lingual gingivae. Not anaesthetized fully. Buccal gingivae and sulcus in molar region. These tissues are supplied by the (long) buccal nerve and require separate infiltration local anaesthesia for surgical procedures. Inferior dental block technique 1. Patient seated comfortably – neck supported and slightly extended such that when the mouth is fully open, the lower occlusal plane will be approximately horizontal. 2. Index finger or thumb of the non-syringe-holding hand is passed posteriorly in the buccal sulcus until it lies in the retromolar triangle (formed by meeting of external oblique line and mylohyoid line). 3. Visualize the almost vertically running pterygomandibular raphe (runs from pterygoid hamulus to medial aspect of mandible in third molar region). 4. Introduce needle from premolars of opposite side such that: a. It is parallel to lower occlusal plane. b. It is halfway up the finger lying in the retromolar triangle. c. It passes lateral to the raphe. 5. The needle is advanced, usually 2.5 cm, until bone is felt – then withdrawn 1–2 mm. Never advance needle to hub as this will make retrieval impossible should the needle fracture. 6. Aspirate – if blood noted in cartridge, then move needle a millimetre or so and aspirate again. 7. Inject slowly – using most of 2.2 ml cartridge and keep injecting on withdrawal to deposit solution around the lingual nerve. Assessment of effect of the block This is accomplished by asking the patient to describe subjective feelings, most easily felt on lower lip and chin. Early anaesthesia is often described as a tingling sensation or ‘pins and needles’. Later description may be of a puffy, swollen, rubbery or thick feeling. Objective assessment may be accomplished by using a dental probe (on the gingivae). When testing anaesthesia, do not ask the patient simply to report if he/she feels anything (many will be aware of touch or pressure) – ask if pain or discomfort is felt. Remember to supplement the ID nerve block with a long buccal nerve block for periodontal and oral surgical procedures in the mandible. Mental nerve block Tissues anaesthetized. Pulp and periodontium of mandibular first premolar to central incisor with supporting bone. Variably, second premolar. Lip, chin and adjacent sulcus and cheek to the above teeth. For extractions or surgery, a lingual infiltration must also be given. http://dentalebooks.com 206 • C L I N I C A L D E N T I S T RY Technique Essentially an infiltration technique around the mental foramen but aspiration prior to depositing solution is necessary. The mental foramen normally lies halfway between the gingival margin of the premolars and the lower border of mandible in the dentate mouth. Infraorbital nerve block Tissues anaesthetized. Upper lip, cheek, side of nose and lower eyelid; buccal gingivae and sulcus from midline to premolar region; incisors, canine and premolars (anterior and middle superior alveolar nerves arise from the infraorbital nerve in the infraorbital canal). Technique Similar to infiltration but: The needle should be aligned parallel to the long axis of the premolars. The needle enters the tissues about 1.5 cm lateral to the buccal alveolar bone surface where an infiltration would be given. The needle should be advanced about 1.5 cm vertically to the region of the infraorbital foramen before aspirating and injecting slowly. • • • Greater palatine nerve block Tissues anaesthetized. Palatal mucoperiosteum up to the canine region. Anterior to this, the innervation is derived from the nasopalatine nerve. Technique A more compressible area can be found on palpation of the hard palate between the midline and the palatal gingival margin of the teeth. This is less bound down to underlying bone and therefore less painful on injection. The nerve can be blocked at any point along its anatomical path depending on the surgical site. This injection is painful. Application of surface anaesthetic and firm finger pressure for 10–20 seconds by the non-syringe-holding hand before sliding the needle in close to this finger can minimize the pain. Thereafter, only a few drops need be introduced slowly. For upper wisdom teeth, it may be less uncomfortable to inject a few drops close to the palatal cervical margin of the tooth on the attached gingiva. Nasopalatine nerve block Tissues anaesthetized. Palatal mucoperiosteum of anterior hard palate related to canines and incisors. http://dentalebooks.com Pain and an x iety m ana g e m ent • 207 Technique This is a very sensitive region and injections in this area are unpleasant. Firm finger pressure over the nasopalatine papilla (after application of topical anaesthetic) and introduction of needle from one side of the papilla may reduce the pain. It is also worthwhile putting a drop of anaesthetic solution just under the epithelium before proceeding to inject deeper into the foramen region. Very small amount needed and delivered slowly. Immediate blanching of the area is often noted. Intraligamental The LA solution is injected into the periodontal ligament of the tooth but reaches its pulpal nerve supply by diffusing into cancellous bone through perforations in the tooth socket wall. It is therefore a form of intraosseous injection. Tissues anaesthetized Pulp and periodontium of the tooth and adjacent gingivae. Technique Insert an extra short 30 gauge needle at about 30 degrees to the long axis, at the mesiobuccal aspect of the tooth. Advance the needle until it meets resistance. Ideally position the needle bevel toward the socket wall. Deliver about 0.2 ml LA into the periodontal ligament of each root. The operator should feel some resistance to flow of the LA solution. Intrapapillary After a standard buccal infiltration, an extra short 30 gauge needle is inserted into the papilla from a buccal approach at 90 degrees to the gingiva and a small volume of local anaesthetic solution injected until the papilla blanches. If the needle is then forwarded deeper into the papilla and more solution injected the palatal aspect of the papilla will blanch. This area of palatal mucosa can then be used as the injection site for a painless palatal injection (known as a ‘chasing’ LA technique). What if the LA fails? Every clinician will have LA failures during their career. The best way to rectify this and obtain good local analgesia is to try and think why the failure may have occurred (Table 9.2) and address the issue. The first approach to failed LA involves checking your technique has been correct (e.g. was there early bony contact in an inferior dental block) and then repeating the injection, having corrected the http://dentalebooks.com Dental anxiety or phobia may heighten patient’s pain perception Patient with a difficulty in cooperating may not maintain the mouth open posture necessary to properly position an inferior dental block injection 5. Tissue inflammation causing nerve fibres to become hyperalgesic Psychology or understanding, e.g. Pathology, e.g. Local analgesic technique, e.g. Choice of local analgesic, e.g. Individual patient variation in position of nerves and foramina e.g. a ‘high’ mandibular foramen Accessory nerve supply, e.g. lower incisors with contralateral innervation Anatomy, e.g. Block techniques (e.g. mental or inferior dental) are ‘blind’ techniques and rely on operator’s ability to use anatomical landmarks correctly; misplaced injections are the main cause of LA failure LA without a vasoconstrictor will produce analgesia of very limited duration Operator-dependent factors Patient-dependent factors • TABLE 9.2 Causes of failed local analgesia 208 C L I N I C A L D E N T I S T RY http://dentalebooks.com Pain and an x iety m ana g e m ent • 209 technique. If this fails to produce good LA, then supplemental techniques may help, e.g. intraligamentary injection or an injection aimed to produce analgesia in accessory nerves. What complications may occur? Local anaesthetics in dentistry have a good safety record so the majority of complications described below are rare. Systemic complications Vasovagal syncope (faint). This most common complication of administration of LA is usually due to needle phobia/dental anxiety. Risk can be reduced, but not eliminated, by always administering LA with the patient semi-supine. Allergy. True allergy to LA is rare. Patients often mistakenly report as an allergy, a faint during LA administration or palpations (usually related to intravascular administration). Where the history is not suggestive of either of the above, referral to a specialist allergy service may be required. Historically, most allergic reactions to LA were caused by preservatives, but most modern LA solutions are preservative-free. Toxicity. Toxicity to LA in dentistry is rare. When it does occur it is usually due to intravascular injection or overdose. Intravascular injection can occur in every dentist’s practice, most commonly with inferior dental block injections. Signs/symptoms of intravascular injection include pain, localized blanching of the skin, palpitations and dizziness. Intravascular injection is best prevented by regular aspiration before and during every LA injection (including infiltrations) and by following maximum dose guidance. Local complications. Failure to achieve adequate local analgesia. As discussed above, reflection regarding accuracy of technique and use of supplemental techniques will often address this issue. Haematoma. Small intraoral haematomas (e.g. in the sulcus following infiltration analgesia) are of no consequence. Risk of significant haematoma formation in deeper tissues is reduced by regular aspiration and slow delivery of LA during block injections. Trismus. If this occurs after an inferior dental block injection, it may have been caused by haematoma formation in medial pterygoid muscle. Management involves exercises to progressively increase mouth opening. Antibiotic management is occasionally indicated. Physical or chemical trauma to the nerve. During a regional block injection, such as an inferior dental or mental block, the needle tip may make contact with the nerve producing prolonged anaesthesia or paraesthesia. Nerve damage following a block injection is also more likely with higher concentrations (i.e. higher percentage) of LA http://dentalebooks.com 210 • C L I N I C A L D E N T I S T RY solution, so it is advisable to use less concentrated solutions for block injections. Facial paralysis. This is a recognized complication of an inferior dental block injection and results from the deposition of LA solution around the facial nerve as it passes through the parotid gland. The risk is reduced by ensuring the needle makes bony contact before delivery of the LA solution. The paralysis is of limited duration (approximately 1 hour) and affects all branches of the facial nerve on the ipsilateral side to the LA injection. Patient reassurance is important, as is prevention of corneal abrasion by use of a protective eye dressing until the blink reflex returns. Needle fracture. The likelihood of needle breakage is reduced if the needle is not bent or inserted to its hub. Needle-stick injury. Administration of LA is the most common cause of contaminated needle-stick injury in dentistry. Risk can be minimized by use of safety syringe/needle systems, not resheathing, and by careful clinical practice. Support staff are at particular risk. Conscious sedation (CS) The General Dental Council accepted definition of conscious sedation is: Definition ‘A technique in which the use of a drug or drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact is maintained throughout the period of sedation. The drugs and techniques used to provide conscious sedation should carry a margin of safety wide enough to render loss of conscious unlikely’. When might sedation be indicated? • • • • anxiety/phobia ‘unpleasant’, usually surgical, procedures, e.g. surgical removal of lower third molar medical conditions exacerbated by stress, e.g. ischaemic heart disease, epilepsy disabilities/conditions which reduce ability of patients to cooperate with treatment, e.g. learning impairment, movement disorders such as Parkinson’s disease, dementia. What is involved in patient assessment for sedation? Patients should be formally assessed regarding their suitability for sedation and the technique most likely to be suitable for them and their dental treatment. This assessment is ideally undertaken prior to a sedation treatment appointment. http://dentalebooks.com Pain and an x iety m ana g e m ent • 211 Full medical, dental and social histories form the basis of the assessment. Dental anxiety may be assessed informally, ‘What is it about dental treatment that worries you?’ or formally using a validated questionnaire, e.g. the Modified Dental Anxiety Questionnaire (MDAS) (Figure 9.2). Each question scores a maximum of 5, with a score of ≥19 suggestive of a high level of dental anxiety. CAN YOU TELL US HOW ANXIOUS YOU GET, IF AT ALL, WITH YOUR DENTAL VISIT? PLEASE INDICATE BY INSERTING ‘X’ IN THE APPROPRIATE BOX 1. If you went to your Dentist for TREATMENT TOMORROW, how would you feel? Not Anxious Slightly Anxious Fairly Anxi ous Very Anxious Extremely Anxious 2. If you were sitting in the WAITING ROOM (waiting for treatment), how would you feel? Not Anxious Slightly Anxious Fairly Anxious Very Anxious Extremely Anxious 3. If you were about to have a TOOTH DRILLED, how would you feel? Not Anxious Slightly Anxious Fairly Anxious Very Anxious Extremely Anxious 4. If you were about to have your TEETH SCALED AND POLISHED, how would you feel? Not Anxious Slightly Anxious Fairly Anxious Very Anxious Extremely Anxious 5. If you were about to have a LOCAL ANAESTHETIC INJECTION in your gum, above an upper back tooth, how would you feel? Not Anxious Slightly Anxious Fairly Anxious Very Anxious Extremely Anxious Instructions for scoring (remove this section below before copying for use with patients) The Modified Dental Anxiety Scale. Each item scored as follows: Not anxious Slightly anxious Fairly anxious Very anxious Extremely anxious = = = = = 1 2 3 4 5 Total score is a sum of all five items, range 5 to 25: Cut off is 19 or above which indicates a highly dentally anxious patient, possibly dentally phobic Figure 9.2 Modified dental anxiety questionnaire. Reproduced with permission from http://www.st-andrews.ac.uk/dentalanxiety/ http://dentalebooks.com 212 • C L I N I C A L D E N T I S T RY Since dental anxiety is but one of the indications for the use of conscious sedation in dentistry, an assessment tool, the Index of Sedation Need (IOSN; Table 9.3) has been developed, which incorporates MDAS but also considers contributory medical history, behavioural history and treatment complexity factors. It is designed to support, but not replace, clinical decision-making. Valid written consent is obligatory for all treatment under conscious sedation. The patient’s baseline vital signs (blood pressure, oxygen saturation and pulse rate) are recorded. TABLE 9.3 Index of sedation need (IOSN) Domain Indicators Score 1. Dental anxiety MDAS 5–9 (minimal anxiety) MDAS 10–12 (moderate anxiety) MDAS 13–17 (high anxiety) MDAS 18–25 (very high anxiety) 1 2 3 4 2. Medical & behaviour indicators None Systemic disorders that may be exacerbated by treatment (e.g. angina, epilepsy, hypertension) Systemic disorders that compromise ability to cooperate (e.g. parkinsonism, multiple sclerosis) (ASA II usually scores 2/3; ASA 3 scores 4) Gag reflex 1 2, 3 or 4 3. Treatment complexity Routine, e.g scaling, single rooted tooth extraction, anterior endodontic treatment, single quadrant restorations Intermediate, e.g. root planing, multirooted extraction, posterior endodontics, two quadrant restorations, surgical extraction without bone removal Complex, e.g. surgical extraction with bone removal; periodontal surgery High complexity, e.g. multiples of the above 1 2 3 4 SEDATION NEED = domains 1 + 2 + 3 Total rank score Source descriptor Sedation need 3–4 Minimal need No 5–6 Moderate need No 7–9 High need Yes 10–12 Very high need Yes www.saad.org.uk/wp-content/uploads/2012/11/IOSN-Form.pdf Reprinted by permission from Macmillan Publishers Ltd: British Dental Journal 2011;9:211(5):E10. Copyright 2011. From: Coultard P, Bridgman CM, Gough L, Longman L, Pretty IA, Jenner T. Estimating the need for dental sedation. 1. The Indicator of Sedation Need (IOSN) – a novel assessment tool. http://dentalebooks.com Pain and an x iety m ana g e m ent • 213 Arrangements for postoperative care must be made at the assessment visit since the majority of patients (with the exception of some patients sedated with inhalation sedation) require a competent adult to accompany them home and remain with them for the remainder of the day. What are the commonly used sedation techniques in dentistry? The significant majority of patients requiring sedation for dentistry can be successfully managed using inhalation sedation (IS) with nitrous oxide/oxygen or intravenous sedation (IVS) with midazolam. Both techniques have the advantage of being titratable to patient response and are suitable for use by a dentist who is acting as the operator and the sedationist, assisted by a second sedation trained person (usually a sedation dental nurse). Inhalation sedation (or relative analgesia: RA) Inhalation sedation with a nitrous oxide/oxygen mixture is delivered via a nasal hood using a dedicated machine that cannot deliver less than 30% oxygen to the patient. Patients are usually optimally sedated at 25–50% nitrous oxide. Nitrous oxide is not potent in anaesthetic terms and so has a wide margin of safety. The technique relies substantially on the behaviour management skills of the clinical team and the cooperation of the patient to breathe through their nose. Onset and recovery from sedation are rapid and depth of sedation can be altered at any point during the procedure. It is the sedation method of choice for children and is often efficacious in anxious adults (Figure 9.3). There are few contraindications to IS: • • • • • • nasal obstruction first trimester of pregnancy severe learning disability chronic obstructive airways disease recent surgery to the eye recent chemotherapy with bleomycin. Signs and symptoms of adequate sedation: • • • • • • • patient appears more physically relaxed blink rate is usually reduced patient can maintain an open mouth decreased ‘fidgeting’ movements decreased response to painful stimuli paraesthesia/tingling warmth http://dentalebooks.com 214 • C L I N I C A L D E N T I S T RY Figure 9.3 Anxiety management with inhalation sedation and local anaesthesia in a patient undergoing restorative treatment under rubber dam. • • feeling of heaviness detachment. Equipment. To deliver the correct mixture of nitrous oxide and oxygen gases, specific equipment is required. Delivery systems include Quantiflex MDM, Porter and Matrix (Figure 9.4). Written, informed consent is required for inhalation sedation. Technique for inhalation sedation 1. The patient should be informed of the objectives of the technique and of the equipment to be used in a manner appropriate for their age, cognition and level of anxiety. The clinician aims to use only closed questions throughout the sedation treatment, requiring only yes and no answers, to prevent lightening of sedation level and increased exposure of clinicians to nitrous oxide. 2. The patient should be seated comfortably. 3. After demonstration of the position of the nosepiece, the patient should settle the mask over the nose. 4. The flow control should then be adjusted to keep the reservoir bag full while 100% O2 is breathed. 5. N2O should be increased reasonably quickly at first, i.e. 10% to 15% to 20% at 1-minute intervals, thereafter at smaller 5% increments. http://dentalebooks.com Pain and an x iety m ana g e m ent • 215 Figure 9.4 An inhalation sedation machine. 6. The operator should talk quietly and encouragingly, asking only for nodding responses. Visual imagery and progressive relaxation techniques may be helpful. 7. When the patient is adequately sedation (see below), dental treatment may be commenced, starting with delivery of local anaesthesia. 8. When nearing completion of treatment, the N2O concentration is reduced in 10–20% increments until 100% oxygen in reached. 9. 100% oxygen should be administered for 2–3 minutes at the end of the procedure for at least 2 minutes to prevent diffusion hypoxia which can cause headache. 10. Recovery from N2O sedation is rapid but it is wise for the patient to remain in a supervised environment for a further 15–20 minutes to ensure full recovery. http://dentalebooks.com 216 • C L I N I C A L D E N T I S T RY Postoperative instructions after inhalation sedation Age-appropriate verbal and written postoperative instructions must be provided for the patient and their escort. Adults (16 years and above) who have had inhalation sedation may be discharged without an escort at the discretion of the sedationist. Postoperative advice should include precautions relating to the dental treatment and the sedation. After inhalation sedation, precautions may include advice not to drive a car or operate machinery for up to 2 hours after treatment. Chronic exposure of staff to nitrous oxide The Health and Safety Executive (HSE) require staff exposure to nitrous oxide to be limited to 100 parts per million over 8 hours. This is designed to prevent the effects of chronic exposure including bone marrow depression and reproductive effects. Active scavenging systems, well-ventilated surgeries and good sedation technique all reduce staff exposure to nitrous oxide. Intravenous sedation Intravenous sedation in dentistry usually involves the administration of midazolam using a titration method via an in-dwelling cannula (Figure 9.5). Midazolam is a benzodiazepine and acts by enhancing the action of γ-aminobutyric acid (GABA), an inhibitory neurotransmitter, in the central nervous system. The overall effect is anxiolysis, sedation and muscle relaxation. Patients usually also have a hazy memory of events for the period after midazolam is administered, anterograde amnesia. Midazolam produces respiratory depression to some degree, though it is usually not clinically significant. It is therefore mandatory to measure the patient’s arterial oxygen saturation via pulse oximetry throughout treatment to ensure early detection Figure 9.5 In-dwelling cannula. http://dentalebooks.com Pain and an x iety m ana g e m ent • 217 and treatment of hypoxia. If the arterial oxygen saturation falls, a hierarchy of interventions is implemented ranging from a simple instruction to the patient to take deep breaths or delivery of supplemental oxygen via nasal prongs while treatment continues to abandonment of treatment, airway support and administration of flumazenil (200–500 mcg). Flumazenil, a benzodiazepine competitive antagonist, must be available in the dental surgery where midazolam sedation is undertaken so that it is available to reverse the sedation in an emergency. IV midazolam technique • • • • • • • • • • Prior to preparing the patient midazolam 5 mg/5 ml (or 10 mg/10 ml) is drawn up and the syringe labelled. A non-pharmacologically active agent, e.g. water for injection/normal saline is also drawn up and the syringe labelled. Preoperative patient checks include vital signs, consent, medical history and availability of postoperative patient escort. The cannula is placed, usually in the hand or forearm, and its patency checked with water for injection/normal saline. Midazolam is then administered using a titration technique, e.g. Give 2 mg and wait 1 minute Give a further 1 mg every 30–60 seconds while continuing to communicate with the patient and monitoring them for signs of sedation The majority of patients sedate in the range of 2–10 mg As patients become sedated they will usually become less talkative, appear more physically relaxed and their eyes less focused. Once the patient is accepting of treatment, local anaesthetic is administered and treatment carried out in the normal way. The patient is recovering during treatment so it is best to carry out the most unpleasant aspects of treatment first, e.g. administration of LA; dental extraction. The window for treatment ranges from 10–40 minutes on average. Patients must remain monitored by sedation staff until they are recovered sufficiently to walk unaided. Patients are usually fit for discharge about 1 hour after midazolam administration. Postoperative instructions: remind patient and carer that they must not drive, operate machinery/appliances, make important decisions or be in charge of others for the remainder of the day. • • • Are there other sedation techniques available? Oral and transmucosal (intranasal spray) sedation with midazolam are useful in patients who cannot comply with cannulation for IV midazolam sedation (e.g. severe needle phobia; severe learning disability). Both techniques involve administering a bolus dose of drug to the patient (usually 10–20mg orally or 10mg intranasally). These techniques should only be used by clinical teams who are competent in IV sedation since IV cannulation may be required to ‘top up’ the http://dentalebooks.com 218 • C L I N I C A L D E N T I S T RY sedation with IV midazolam or to administer flumazenil in the event of over-sedation. IV sedation with other drugs. Such as propofol (a short-acting general anaesthetic induction agent) are advanced techniques with less wide margins of safety and should be administered by a sedationist who is not providing the dental treatment. Postoperative instructions after intravenous sedation Postoperative advice should include precautions relating to the dental treatment and the sedation. The patient and their accompanying escort must be reminded that the escort is taking responsibility for the patient after treatment and must be able to stay with them overnight if necessary. The patient should not drive, ride a bicycle or operate machinery until the following day – in some cases this may be for as long as 24 hours. For the same time period, the patient must not take responsibility for the care of others, use sharp implements or cook. Patients should be reminded that it would be unwise to make any irreversible decisions for 24 hours following your treatment. And that care should be taken when using the internet for personal communication. General anaesthesia (GA) Whilst the majority of dental patients can be successfully managed under local anaesthesia +/− conscious sedation, there remain significant numbers where general anaesthesia is the pain and anxiety control modality of choice. Indications for dental general anaesthesia include: • • • Very young patients requiring multiple quadrant dentistry. Patients undergoing procedures where the surgical complexity indicates the use of GA, e.g. enucleation of large cystic lesion; complex third molar removal. Patients with severe learning disabilities where sedation is ineffective or contraindicated. A patient who is treated under GA is in a controlled, reversible state of unconsciousness produced by drugs which cause amnesia, analgesia, muscle paralysis, and sedation. Nevertheless, most cases of dental GA are carried out on a day-stay basis, i.e. the patient is treated and is discharged home accompanied on the same day. What is involved in patient assessment for dental general anaesthesia? Assessment for GA may be carried out by the dental team as part of the dental assessment or at a specific pre-assessment clinic usually led by general nurses. http://dentalebooks.com Pain and an x iety m ana g e m ent • 219 Assessment usually includes: • • • • • • Past medical history Drug history Social history (including smoking history) Anaesthetic history Baseline vital signs (blood pressure, arterial oxygen saturation, pulse rate), height, weight and body mass index are recorded. Dependent on the age of the patient and the nature of their surgery, further investigations such as ECG and blood tests may be undertaken. Checks will be made to ensure valid consent for the operation has been obtained. While elective GA for dentistry is very safe, the anaesthetist or dentist will normally discuss the relevant adverse effects and complications of GA with the patient or their parent, as shown in Table 9.4. Patients are also given specific information about what to do to prepare for their operation. This includes: • • • • • consider giving up or reducing smoking consider trying to lose weight if very overweight having no food for 6 hours before the operation having no fluids for 2 hours before the operation take routine medicines as normal. How is the general anaesthetic administered? The patient’s GA is administered by an anaesthetist, working in a team with a trained assistant. Induction of anaesthesia usually happens in an anaesthetic room adjacent to the operating theatre. TABLE 9.4 Adverse effects and complications of general anaesthetic Very common/common adverse effects (1 in 10–1 in 100) Uncommon adverse effects (1 in 1000) Rare or very rare adverse effects (1 in 10 000–1 in 100 000) Postoperative nausea and vomiting Chest infection Damage to eyes Sore throat Damage to teeth Serious allergy to drugs Dizziness, headache Awareness during the operation Death Minor damage to lip or tongue Confusion Reproduced here with permission from The Royal College of Anaesthetists. Originally published as part of the RCoA Patient Information series of leaflets (2014) (www.rcoa.ac.uk/patientinfo). http://dentalebooks.com 220 • C L I N I C A L D E N T I S T RY Checks are made to ensure the correct patient is having the correct operation. A blood pressure cuff, ECG leads and pulse oximeter probe are attached to the patient and results recorded. If cooperation allows, patients normally breathe 100% oxygen for a few minutes before the anaesthetic begins. General anaesthesia is induced by giving drugs (e.g. propofol) via an in-dwelling cannula or by breathing an anaesthetic gas (e.g. sevoflurane) mixed with oxygen. The patient’s airway is protected either by a supraglottic device such as a laryngeal mask airway or an endotracheal tube which is passed into the trachea. The airway device is secured in place and the patient either breathes spontaneously or their breathing is supported by intermittent positive pressure ventilation. It is common practice for a swab (throat pack) to be inserted into the oropharynx to prevent debris from dental treatment contaminating the airway. During GA vital signs continue to be monitored and additional drugs such as anti-emetics and analgesics and fluids can be given intravenously. Recovery from GA is closely monitored, initially by the anaesthetic team and then by nurses who monitor the patient until they are assessed as fit for discharge or return to the ward. How is the dental treatment performed? A mouth prop, e.g. McKesson prop is used to allow intraoral access. It is common for local anaesthetic to be administered for dental surgery under GA to aid with postoperative pain management and reduce bleeding at the operation site. Dental treatment is then completed in the normal way with close attention to aspiration to ensure all debris is removed prior to reversal of the GA. The clinical team must ensure the throat pack is removed before the airway device is removed. The patient must only be discharged when reflexes have returned, and in the care of a competent adult. Cognitive behavioural therapy (CBT) Cognitive behavioural therapy is a talking therapy which aims to help patients change both the way they think about their anxieties and the behaviours these anxieties cause. In terms of dental anxiety, the CBT approach sees the patient’s thoughts about dental treatment, their feelings (such as anxiety or worry), their sensations (such as palpitations, lightheadedness or nausea) and their actions (such as avoidance of treatment or late cancellation of appointments) as interrelated. It aims to help the patient break this cycle. The National Institute for Health and Care Excellence (NICE) states that evidence-based psychological interventions, such as CBT, can be effective treatments for anxiety disorders such as dental anxiety and are recommended first-line treatments in preference to pharmacohttp://dentalebooks.com Pain and an x iety m ana g e m ent • 221 logical treatment. Unfortunately access to CBT services within the NHS is limited. Hypnotherapy Hypnosis is characterized by a trance-like state and has been described as the quieting of the conscious mind that allows the patient to access their subconscious mind. The therapist then give suggestions to help the patient visualize what it is they want to achieve, such as feeling calmer when having dental treatment or reducing the frequency and intensity of their bruxism. The patient has to have the desire that the hypnosis will be successful. A small proportion of people, about 10%, are not susceptible to suggestion and so hypnosis as an adjunct to pain and anxiety management is not for them. It is recommended that the hypnosis practitioner is also a registered healthcare professional, e.g. a dentist, psychologist, doctor, able to recognize when patients should be referred to psychological services. Specific postgraduate training in hypnosis is required. Acupuncture Acupuncture originated in China more than 3000 years ago and involves insertion of needles into various parts of the body with the intention of managing disease. There is some evidence that it may help in the management of dental anxiety and conditions such as temporomandibular dysfunction in some patients (Figure 9.6). Figure 9.6 Acupuncture in the management of temporomandibular disorder. http://dentalebooks.com 222 • C L I N I C A L D E N T I S T RY Insertion of a needle in an acupuncture point creates a small inflammatory process that stimulates A-δ-nerve fibres located in the skin and muscle. This stimulation inhibits incoming painful sensations to the brain cortex by release of encephalin. Acupuncture is usually used as a supplemental technique in pain management and specific postgraduate training is required. Further reading Girdler, N.M., Hill, C.M., Wilson, K.E., 2009. Clinical sedation in dentistry. WileyBlackwell, Chichester. Meechan, J.G., 2010. Practical dental local anaesthesia. Quintessence Publishing Company, New Malden, UK. Meechan, J.G., Robb, N.D., Seymour, R.A., 1998. Pain and anxiety control for the conscious dental patient. Oxford University Press, Oxford. Scottish Dental Clinical Effectiveness Programme, 2012. Conscious sedation in dentistry. Scottish Dental Clinical Effectiveness Programme, Dundee. The Dental Faculties of the Royal Colleges of Surgeons and the Royal College of Anaesthetists, 2015. Standards for conscious sedation in the provision of dental care. RCS Publications, London. http://dentalebooks.com Drug prescribing and therapeutics Hypersensitive (allergic) reactions 224 10 Therapeutics 228 Areas of recent controversy 234 General Dental Practitioners (GDPs) treat patients mainly by physical intervention such as restorative, prosthodontic or orthodontic work. In contrast, General Medical Practitioners (GPs) treat patients mainly by prescribing drugs and do very little, if any, physical intervention. This simplification helps to explain that the drugs available to a GDP are limited in scope and are deemed to be all that is necessary for safe and competent dental practice in primary care including implant and dento-alveolar or periodontal surgery. The therapeutic needs of the dental patient in hospital practice, however, may well be much wider so there is less restriction on the drugs available. Frequently medical prescriptions present more problems for dental treatment than the converse but of course, any possible interactions must be checked and if necessary the patient’s physician should be contacted. • • • • • • Anticoagulation therapy is a prime example that could make LA blocks or tooth extraction hazardous – but reducing the dosage may put the patient in jeopardy from thromboses. Bisphosphonates, commonly prescribed for osteoporosis or cancers in bone, can result in osteonecrosis of the jaws (mainly if given intravenously). Other medications such as other antiresorptive drugs (denosumab) and anti-angiogenic therapies can also occasionally cause Medication-Related OsteoNecrosis of the Jaws (MRONJ). The osteonecrosis can particularly follow oral or periodontal surgery or endodontic therapy. Long-term analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) may cause prolonged bleeding, allergies or peptic ulceration. Long-term antibiotic use, e.g. for chronic obstructive pulmonary disease (COPD) may make the choice of an antibiotic effective against a dental infection difficult. Immunosuppressant therapy (e.g. after organ transplantation) can result in immune deficiency as does chemotherapy for cancer – increasing the risk of infections. Radiotherapy affecting the jaws produces a liability to osteoradio­ necrosis (ORN). http://dentalebooks.com 224 • • • C L I N I C A L D E N T I S T RY Alternative or complementary agents sometimes cause a bleeding tendency or drug interactions. Grapefruit and some other fruit juices or foods can affect the effects of various drugs such as erythromycin. Some Over The Counter (OTC) agents may cause interactions or adverse reactions. Hypersensitive (allergic) reactions Every drug (even aspirin) has the possibility of causing adverse reactions, some considerably more than others. A classical example is penicillin – the reaction can be immediate (Type I that occurs minutes after exposure, late-phase that occurs 2–4 hours after exposure) or type II hypersensitivity where penicillin can bind to red blood cells, causing them to be recognized as different; B-cell proliferation will take place and antibodies are produced. The effect of an immediate allergic reaction can be a dramatic anaphylaxis. Patients who are allergic to one penicillin will be allergic to all and those with a history of immediate hypersensitivity to penicillins may also react to the cephalosporins. Giving drugs by mouth means that any reactions will be slower and more manageable than giving by injection (parenteral). As a general rule, if drugs must be given by injection (like a local anaesthetic) do it slowly, when it is also less painful. Anaphylaxis (see also Chapter 21) Individuals at considerable risk of anaphylaxis need to carry adrenaline at all times in the form of two auto-injectors. The clinician and nurses should ask the patient how to use them in case of collapse. Recognize, treat, reassess • • • Recognition: if a patient has acute onset airway and/or breathing problems, or hypotension especially if the skin is affected (e.g. urticaria), strongly consider treating as anaphylaxis Treatment: adrenaline 0.5 mg (half an ampoule of 1 mg/1 ml) intramuscularly lateral mid-thigh (adult), through clothing if necessary – repeat after 5 minutes if no response. Call an ambulance. Reassess and monitor closely. Use oxygen. Patient may be semirecumbent if wheezing or vomiting, otherwise lie flat. Get help. Don’t panic. Recommendations • Have a clearly labelled anaphylaxis kit, with adrenaline, needles, syringes. http://dentalebooks.com D r u g p rescri b in g and t h era p e u tics • • 225 Teach all clinical staff, including nurses, anaphylaxis recognition and treatment. Suspected adverse drug reactions should be reported to the Medicines and Healthcare products Regulatory Agency (MHRA) through the Yellow Card Scheme (www.mhra.gov.uk/yellowcard). At the time of writing, this is undergoing revision. British National Formulary The BNF (British National Formulary) is an essential source of in­­ formation on drug actions, uses, dangers and interactions. It can be searched under the umbrella of NICE (National Institute for Health and Care Excellence) http://www.evidence.nhs.uk/formulary/bnf/ current. Within the BNF there is a section ‘Prescribing in dental practice’ (http://www.evidence.nhs.uk/formulary/bnf/current/guidance-onprescribing/prescribing-in-dental-practice) which has links to sections such as ‘General guidance’ and ‘Drug management of dental and oral conditions’. The Dental Practitioners’ Formulary (DPF) is a list of drugs that may be prescribed by dentists under NHS regulations (http://www.evidence.nhs.uk/formulary/bnf/current/dentalpractitioners-formulary). Dentists, however, may prescribe drugs not on this list by private prescription provided this is for a dentally related condition. Doses quoted in the BNF are conventionally the normal or accepted adult dose. Guidance on suitable children’s doses is included where appropriate. It is a legal requirement in the case of prescription-only medicines to state the age for children under 12 years. There is a separate publication, BNF for Children (http://www.evidence.nhs.uk/ formulary/bnfc/current). Controlled drugs Controlled drugs (symbol CD) are graded broadly according to the harmfulness attributable to a drug when it is misused and are defined in Classes A, B, C. • • • Class A drugs include the opioids/opiates heroin, methadone and morphine Class B includes barbiturates, cannabis, ketamine and codeine Class C, analgesics such as buprenorphine and tramadol, also hypnotics like zopiclone. The Misuse of Drugs Regulations 2001 (and subsequent amendments) define the classes of person who are authorized to supply and possess controlled drugs while acting in their professional capacities and lay down the conditions under which these activities may be carried out. They are grouped into five Schedules, the most restricted are Schedule 1, the least Schedule 5. http://dentalebooks.com 226 • C L I N I C A L D E N T I S T RY See controlled-drugs-and-drug-dependence section of the guidanceon-prescribing. Abbreviations and symbols are used in the BNF. Important among these are, for example: CD3. A controlled drug preparation in Schedule 3. CSM (Committee on Safety of Medicines). Now subsumed under Commission on Human Medicines (CHM). POM (Prescription-Only-Medicine). I.e. it cannot be bought over the counter at a pharmacy. Prescription writing The prescription is the responsibility of the prescriber, not the pharmacist. Manufacturers of drugs use seductively short and easily remembered names for their products such as Amoxil. This is a so-called proprietary preparation and marked ®. The correct non-proprietary (generic) name is Amoxicillin. European law requires the use of the Recommended International Non-proprietary Name (rINN) for medicinal substances, and the BNF conforms to this. The exceptions are adrenaline and noradrenaline (rINN epinephrine and norepinephrine). The NHS provides prescription forms for GPs and hospitals called FP10. Those for Community Dentist use are FP10D. Essential information is to be written in ink or indelible form: 1. Name and address of patient 2. Age of patient (if under 12 years) 3. Total number of days of treatment 4. The generic name of the drug, its form and strength (e.g. metronidazole tablets 200 mg) 5. Instructions as to how and when drug is to be taken, written in English with no abbreviations (e.g. ‘one tablet to be taken three times daily with food’) 6. Delete any space remaining on the form 7. Date and prescriber’s signature 8. On standard NHS forms there is a box for the institution rubber stamp, otherwise the name and address of the prescriber is required. Note More than one drug may be prescribed for a patient on one form. For controlled drugs, the prescriber’s own handwriting should be used in indelible ink throughout and the total quantity of the drug in both words and figures is required. The prescription should http://dentalebooks.com D r u g p rescri b in g and t h era p e u tics • 227 TABLE 10.1 Generally safe drugs in primary care dentistry Dental drug Generally safe if no allergy, bleeding tendency drugs or pregnancy/breastfeeding LA Articaine Lidocaine Mepivacaine Prilocaine Sedation Diazepam Midazolam Analgesia Paracetamol (care with liver disease/alcohol) Antibacterial Penicillins (care with OCP, warfarin) Antifungal Nystatin topical be endorsed with the words ‘For dental treatment only’. The only controlled drugs of relevance to outpatient NHS dental practice are the benzodiazepines – temazepam (CD3) and diazepam (CD4-1). Warnings to patients Patients should be instructed to: • • • • Always take the drug at the recommended time and finish the prescribed course. Stop the drug and contact prescriber immediately if any untoward reaction occurs (e.g. skin rash or severe diarrhoea). Know the side-effects or interactions, e.g.: • increased effect of anticoagulants with antibiotics, antifungals and NSAIDs. See Table 10.1. • know about the interaction of metronidazole with alcohol. Medicines should be kept safely out of the sight and reach of children and the use of ‘child safe’ containers is essential. When no longer needed, medicines should be disposed of by returning them to the local pharmacist, not discarded where children may find and swallow them. Patients at particular risk from drugs Children. Doses should be appropriately reduced by age or body weight. Appropriate doses are listed in the BNF and a BNF for children is available. Elixirs are preferable for oral ingestion. If under 12 years, the age must be included in the prescription. ‘Sugar-free’ preparations should be prescribed where available. Drugs contraindicated include tetracyclines (because of the tooth-staining), codeine (respiratory depression) and aspirin (risk of provoking Reye’s syndrome). http://dentalebooks.com 228 • C L I N I C A L D E N T I S T RY Older people. May show exaggerated reactions to drugs, and doses may need to be modified. Gastrointestinal (GI) haemorrhage is more likely with NSAIDs and these should be prescribed with caution. Polypharmacy is common; possible interactions should be identified. Patients often get confused about which drugs are to be taken at which times, with the possibility of neglecting important medication. Try to avoid adding to their confusion. Pregnancy. Prescribe only when absolutely essential. Use the welltried, safer preparations. Teratogenic effects are most likely in the first trimester. Second and third trimester effects are mainly on growth, development and drug toxicity to the foetus. Breastfeeding. Some drugs pass into the milk and are thereby ingested by the baby. This is potentially dangerous. Liver disease. Many drugs are metabolized through the liver. Impaired liver function may affect the breakdown of drugs; certain drugs may further damage the organ. Check BNF listings. Kidney disease. As many drugs are excreted through the kidney, impaired function may lead to: increased drug levels in the plasma; rising sensitivity to certain drugs; poor tolerance to side-effects. Certain drugs should be avoided, and some may require dose reduction. For all the above groups check BNF listings under ‘Guidance on Prescribing’ and appropriate appendices. Therapeutics Dental and orofacial pain Alleviation of pain is probably the most common task for the GDP and infection is the main cause whether it be pulpal, intra-osseous or mucosal (Chapter 9). Analgesics should be regarded as a temporary measure until the cause of the pain has been dealt with. Dental pain of inflammatory origin, such as that associated with pulpitis, apical infection, localized osteitis or pericoronitis is usually best managed by treating the infection, providing drainage, restorative procedures, and other local measures such as incising an abscess. In the case of pulpitis, intra-osseous infection or abscess, reliance on analgesics alone is usually inappropriate. Similarly the pain and discomfort associated with acute problems of the oral mucosa (e.g. acute herpetic gingivostomatitis, erythema multiforme) may be relieved by benzydamine mouthwash or spray http://dentalebooks.com D r u g p rescri b in g and t h era p e u tics • 229 until the cause of the mucosal disorder has been dealt with. However, where a patient is febrile, the antipyretic action of paracetamol (acetaminophen) or an NSAID such as ibuprofen is often helpful. Most dental pain is relieved effectively by NSAIDs. Paracetamol has analgesic and antipyretic effects but no anti-inflammatory effect. NSAIDs that are used for dental pain include ibuprofen, diclofenac, and aspirin (see Table 10.1). Any analgesic given before a dental procedure (pre-emptive dosage) should be one that has a low risk of increasing postoperative bleeding. In the case of pain after the dental procedure, taking an analgesic before the effect of the LA has worn off can improve pain control. Chronic orofacial pain Chronic oral and facial pain including persistent idiopathic facial pain (also termed ‘atypical facial pain’) and temporomandibular dysfunction may call for prolonged use of analgesics or for other drugs. Tricyclic antidepressants such as amitriptyline may be useful for idiopathic facial pain, but are not in the DPF. Disorders of this type require specialist referral and psychological support to accompany drug treatment. Temporomandibular dysfunction can be related to anxiety in some patients who may clench or grind their teeth (bruxism) during the day or night. The muscle spasm (which appears to be the main source of pain) may be treated empirically with an overlay appliance which provides a free sliding occlusion and may also interfere with grinding. In addition, diazepam (in the DPF), which has muscle relaxant as well as anxiolytic properties, may be helpful but it should only be prescribed on a short-term basis during the acute phase since it is addictive. Analgesics such as aspirin or ibuprofen may also be required. Neuropathic pain Neuropathic pain, which occurs as a result of damage to neural tissue, includes peripheral neuropathies (e.g. due to diabetes, chronic excessive alcohol intake, HIV infection, chemotherapy, idiopathic neuropathy), trauma, central pain (e.g. pain following stroke, spinal cord injury) and post-herpetic neuralgia (peripheral nerve damage following acute herpes zoster infection (shingles)). Neuropathic pain is generally managed with a tricyclic antidepressant or with certain antiepileptic drugs. Amitriptyline and pregabalin are effective treatments but are not in the DPF. Trigeminal neuralgia is also caused by dysfunction of neural tissue, but its management is distinct from other forms of neuropathic pain. If it is possible to identify the trigger location, it may be at a site where LA can be used as a diagnostic aid and to help the http://dentalebooks.com 230 • C L I N I C A L D E N T I S T RY patient having intense pain. The pain relief after LA sometimes lasts longer than the normal duration of local anaesthesia. Carbamazepine (in the DPF) is an anti-epileptic that can be used as a diagnostic trial and, taken during the acute stages of trigeminal neuralgia, reduces the frequency and severity of attacks. It is very effective for the severe pain associated with trigeminal neuralgia and (less commonly) glossopharyngeal neuralgia, but side-effects are common and monitoring for HLA type to prevent reactions, blood, hepatic and skin disorders is essential. Treatment of trigeminal neuralgia and other neuropathies is thus in the domain of specialist care. Anxiety Alleviation of anxiety (anxiolysis) is essential for successful treatment of the dental patient. Drugs are not always indicated as there are many ways of dealing with anxiety. The class of drugs called benzodiazepines all have sedative anxiolytic properties and temazepam (CD3) is useful as a short term measure. Diazepam (CD4-1) has a longer duration of action but the muscle relaxant property sometimes helps. Patients must be warned about the sedative effects and driving or working with machinery. Sedation with intravenous midazolam needs extra training and the support of qualified assistants. Infections Treatment of infection is drainage (‘where there is pus, let it out’ old Latin maxim ‘ubi pus, ibi evacua’ and ‘do not let the sun set on pus’) and often also with antibiotics. Use of antibiotics should be kept to a minimum in view of the serious global issue of antimicrobial resistance and, as with analgesics, local measures should be used first. For example, first stage endodontic therapy, opening the root canal(s) for drainage in the case of pulpitis and localized periapical infection may be sufficient. Similarly, mild pericoronitis and gingival infection may respond to debridement and chlorhexidine mouth rinse. Rare chlorhexidine reactions have been fatal. However, where the infection is clearly more extensive, e.g. acute necrotizing ulcerative gingivitis, and there is soft tissue swelling and systemic effects, antibiotics should be prescribed. Swelling of the submandibular region has the potential to compromise the airway so urgent referral to hospital is indicated (Chapter 14). Many oral infections are caused by mixed Gram-negative and Gram-positive bacteria, so empiric use of broad-spectrum antibiotics is justified and where the source is probably an anaerobic site such as a deep gingival pocket or pericoronitis, metronidazole as monotherapy can be used. Some patients would have difficulty with alcohol http://dentalebooks.com D r u g p rescri b in g and t h era p e u tics • 231 abstinence required for metronidazole and it should be avoided in pregnancy or breastfeeding, so an alternative should be prescribed. Amoxicillin is valuable as a standard therapy for many oral infections as it is broad spectrum and well-absorbed. Amoxicillin and metronidazole can be given together. Alternatives for penicillin-allergic patients are the macrolides erythromycin, azithromycin and clarithromycin (but these may interact with anticoagulants), or the tetracycline doxycycline. In general, however, erythromycin is best avoided as it is metabolized by cytochrome CYP3A4 which can at least precipitate or aggravate ventricular arrhythmias and the cardiac long QT syndrome as well as interacting with other QTprolonging medications and with several other drugs (e.g antiretrovirals, calcium channel blockers, carbamazepine, lovastatin or simvastatin, or pimozide). It should not be used in people with renal or hepatic disease. Oropharyngeal candidiasis generally responds to topical therapy with nystatin or miconazole, but for unresponsive infections or patients with a dry mouth systemic fluconazole may be needed (azole antifungals like miconazole may interact with anticoagulants, and statins – see Tables 10.1, 10.2 and 10.3). TABLE 10.2 Main cautions/contraindications to dental drugs Dental drug Specifics Cautions apart from specific allergies LA plain Cardiac, latex allergy, protease inhibitors (PIs), pregnancy/ breastfeeding LA adrenaline Cardiac, drugs, latex allergy, PIs, pregnancy/breastfeeding Sedation Children, drugs, glaucoma, older people Analgesia NSAID (includes aspirin) Bleeding tendency, children, diabetes, drugs, gastrointestinal ulcer, pregnancy/breastfeeding Antibacterial Any Ciprofloxacin Erythromycin Metronidazole Tetracyclines Warfarin Diabetes Carbamazepine, LQTS, statins, theophylline, warfarin Alcohol, drugs, pregnancy/ breastfeeding, warfarin Children, diabetes, pregnancy/ breastfeeding Antifungal Azoles Statins, warfarin PIs: anti-HIV protease inhibitors LQTS = long QT syndrome (arrhythmia) http://dentalebooks.com Adult 12–17 h; old people 14–17 h (if no renal impairment) 20–60 h (mean ~40 h) Food may delay rate Yes (PT/INR) Yes (vitamin K) Effective half-life Food and other effects on absorption Need for routine monitoring of coagulation http://dentalebooks.com Antidote/reversal agent available No No Acidic environment needed. Absorption may be reduced by drugs such as proton pump inhibitors and antacids Thrombin (inhibits) Dabigatran Factors II, VII, IX and X Proteins C and S Warfarin Targets No No Food increases rate and extent of absorption by 25–35% Young individual 5–9 h; Old people 11–13 h Factor Xa (inhibits) Rivaroxaban and apixaban • TABLE 10.3 Anticoagulants 232 C L I N I C A L D E N T I S T RY Antifungals: ketoconazole, itraconazole Antibiotics: erythromycin, clarithromycin Analgesics: NSAIDs, (antiplatelet agents: aspirin, clopidogrel), ketorolac (diclofenac appears not to interact) Food/herbs: alfalfa, anise, bilberry Antifungals: miconazole, ketoconazole, fluconazole (lesser degree: itraconazole) Antibiotics: erythromycin, clarithromycin, (metronidazole possibly) azithromycin, tetracycline, doxycycline, cephalosporins, levofloxacin Analgesics: NSAIDs, (antiplatelet agents: aspirin, clopidogrel), ibuprofen, diclofenac, paracetamol (prolonged regular use) Food/herbs: cranberry juice, St John’s wort, alcohol, many dietary supplements Green leafy vegetables (Vitamin K), vitamin E Drug and food interactions: decreased anticoagulation Dexamethasone Carbamazepine Rifampicin St John’s wort Dabigatran Warfarin Drug and food interactions: Increased anticoagulation Phenytoin Rifampicin St John’s wort Antifungals: ketoconazole, Itraconazole (miconazole if renal function impaired) Analgesics: NSAIDs, (antiplatelet agents: aspirin, clopidogrel). Food/herbs: grapefruit juice, alfalfa, anise, bilberry Rivaroxaban and apixaban D r u g p rescri b in g and t h era p e u tics http://dentalebooks.com • 233 234 • C L I N I C A L D E N T I S T RY Box 10.1 Risk groups for drug therapy Allergies Bleeding tendency Cardiac Children Drugs: alcohol, aspirin, NSAIDs, OCPs, statins, warfarin Gastrointestinal Glaucoma Kidney Liver Mental health Older people Pregnancy/breastfeeding There has been concern that antimicrobials may reduce the efficacy of oral contraception pills (OCPs) but rifampicin/rifabutin is the only antimicrobial known to interfere with contraception via the: • • • • • combined OCP progestogen-only OCP implant patch vaginal ring. However, if any antibiotics, or an illness, cause diarrhoea or vomiting, the OCP effectiveness may be impaired. Carbamazepine may interfere with the OCP. Drugs commonly used in primary care dentistry Drug use in most patients in primary care dentistry is generally fairly safe (see Table 10.1), but there are risk groups where extra caution should be taken (Box 10.1). Such risk groups include patients with allergies, pregnant patients or those with a co-morbidity such as a bleeding tendency. Some of the main drug cautions or contraindications are shown in Table 10.2. Areas of recent controversy Infective endocarditis Patients at risk of endocarditis include those with valve replacement, acquired valvular heart disease with stenosis or regurgitation, structural congenital heart disease (including surgically corrected or palliated structural conditions), hypertrophic cardiomyopathy, or a previous episode of infective endocarditis. Previously, antimicrobials http://dentalebooks.com D r u g p rescri b in g and t h era p e u tics • 235 were given to ‘cover’ invasive dental procedures in an effort to prevent endocarditis. While almost any dental procedure can cause bacteraemia, there is no clear association with the development of infective endocarditis. Routine daily activities such as tooth brushing also produce a bacteraemia and may present a greater risk of infective endocarditis than a single dental procedure. Antibacterial prophylaxis and chlorhexidine mouthwash are not recommended for the prevention of endocarditis in patients undergoing dental procedures. Such prophylaxis may expose patients to the adverse effects of antimicrobials when the evidence of benefit has not been proven. Now these patients should be advised to maintain the highest possible standards of oral hygiene, and be warned to report to the doctor or dentist any unexplained illness that develops after dental treatment. It is thus prudent to consult the patient’s responsible physician and ensure there is full consultation with the patient. NICE (National Institutes for Health and Clinical Excellence), American Heart Association (AHA) and American Dental Association (ADA) have guidelines, frequently updated. AHA/ADA recommended talking points to discuss with patients are as follows: • • • • IE much more likely to result from frequent exposure to bacteraemias associated with daily activities than bacteraemia caused by procedure (dental, GI, or GU) Prophylaxis may prevent an exceedingly small number of cases of IE Risk of antibiotic-associated adverse events exceeds benefit, if any, from prophylactic antibiotics Optimal oral health and hygiene may reduce the bacteraemia from daily activities and more important than prophylactic antibiotics to reduce IE risk. Anticoagulants. (warfarin, heparin and newer oral anticoagulants) and anti-platelets (e.g. clopidogrel) These agents produce a bleeding tendency and so previously, the agent dosage was lowered before invasive dental procedures. Now most dental situations rely on leaving the medication dose alone and using local measures to obtain haemostasis – pressure with sterile pads (moistened with water, or normal saline solution), absorbable oxidized cellulose sponges, and sutures; and for patients needing surgery or more than three or four extractions, or those with other medical issues, to be referred to a specialist. Commonly used anticoagulants are the coumarin warfarin for long-term treatment and heparin for short-term treatment. The anticoagulant effect of warfarin results predominantly from reduction in http://dentalebooks.com 236 • C L I N I C A L D E N T I S T RY factor II. Because it takes several days for the maximum effect of warfarin to be realized, heparin is normally given first. Warfarin is a vitamin K antagonist causing a prolonged bleeding time assayed by the INR (International Normalized Ratio). Warfarin is most frequently prescribed to control and prevent thromboembolic disorders in atrial fibrillation, after cardiac surgery or organ transplants, after cerebrovascular accident, or in DVT or pulmonary embolism. Warfarin effects begin after 8–12 h, are maximal at 36 h, and persist for 72 h, prolonging the International Normalized Ratio – the ratio of the patient’s prothrombin time to a standardized control. An INR above 1 indicates that clotting will take longer than normal. The management of patients on warfarin should now take into consideration the type of dental procedure, the INR value, the underlying condition for which anticoagulation is used and other risk factors (e.g. hepatic disorders or local inflammation). Surgery is the main oral health care hazard to the patient on warfarin and thus the possibility of alternatives (e.g. endodontics) should always be considered. The INR is used as a guideline to care and should be checked on the day of operation or, if that is not possible, within 24 h prior to surgery. The general rule in patients on warfarin is not to interfere with the drug therapy without consulting the physician; and for patients needing surgery or more than three or four extractions, or those with other medical issues, to be referred to a specialist. The newer oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban and edoxaban are quickly absorbed and have short halflives compared to warfarin so, in the event of excessive anticoagulant activity, discontinuing the drug is usually sufficient. There is no need for routine coagulation monitoring of NOACs in the same way as warfarin using the prothrombin time INR. The known drug interaction profiles of dabigatran, rivaroxaban and apixaban as regards antimicrobials and analgesics are less restrictive than with warfarin. It may be better to confine analgesic use to paracetamol – since NSAIDs have antiplatelet effects which increase a bleeding tendency and can precipitate asthma and other issues. The general rule in patients on NOACs is not to interfere with the drug therapy without consulting the physician; and for patients needing surgery or more than three or four extractions, or those with other medical issues, to be referred to a specialist. Heparin management is typically in hospital or related to dialysis, and effects on bleeding abate after about 6 hours. Antiplatelet agents increase postoperative bleeding but the general rule in patients on antiplatelets, is not to interfere with the drug therapy without consulting the physician; and for patients needing surgery or more than three or four extractions, or those with other medical issues, to be referred to a specialist. http://dentalebooks.com Dental materials Properties of materials 237 Dental amalgams 240 Resin-based composites 243 Glass ionomers 246 Resin ionomer hybrid materials 247 Adhesion and bonding agents 248 Luting cements, linings and bases 250 Temporary cements and restorations 252 11 Impression materials 252 Dental ceramics 256 Casting and wrought alloys 259 Denture base materials 261 Endodontic materials 263 Implant materials 264 Miscellaneous 265 Current ‘growth areas’ in dental materials 267 Properties of materials The properties of dental materials can be classified as: • • • • mechanical, e.g. strength physical, e.g. thermal expansion chemical, e.g. corrosion biological, e.g. toxicity. Dental materials can also be defined by their atomic form: Metals. Crystalline held by primary forces. Polymers. Large chain molecules held by secondary forces, branching and cross-linking. Ceramics. Ionic and covalent crystalline materials, which can exist as an amorphous glass. Composites. A combination of two or more material types, displaying properties of both (the vast majority of dental materials are composite in nature). Mechanical properties Stress. Measurement of the force per unit of cross-sectional area acting on the material. Strain. The fractional deformation when the force is exerted. http://dentalebooks.com 238 • C L I N I C A L D E N T I S T RY Elastic modulus (E). Ratio of stress to strain; this is a measure of the relative stiffness of a material. Stiffer materials exhibit a higher elastic modulus. Elastic deformation. The reversible deformation of a material under load. Plastic deformation. The irreversible deformation of a material under load. Brittleness. Fracture of a material with little or no plastic deformation. Brittle materials are inherently weak under tensile force. Ductility. The ability of a material to undergo permanent tensile deformation without failure. Malleability. The ability of a material to undergo permanent compressive deformation without failure. Hardness. Material hardness is its resistance to indentation. Fracture toughness. The ability of a material to prevent crack propagation. Fatigue strength. Failure of a material below the normal fracture strength due to repeated cyclic stresses. Physical properties Electrical conductivity. The ability of a material to conduct electric charge. Materials with free electrons (e.g. metals) conduct electricity; materials without them (e.g. ceramics) do not. Thermal conductivity. The ability of a material to conduct heat. Thermal expansion. Materials expand as temperature rises and contract as it decreases, due to atomic vibration, quantified by the thermal expansion coefficient. Radio-opacity. The amount of X-ray energy absorbed by a material depends on the composition and thickness of the material. Metals absorb X-rays well, polymers absorb X-rays poorly. Optical properties. Materials may absorb, reflect, refract and transmit light (Figure 11.1). Chemical properties Corrosion. This is an electrochemical process, which involves movement of ions in an aqueous environment, e.g. saliva. Solubility. The amount a material will dissolve in a fluid, e.g. saliva. Oxide layer formation. All metals (except noble metals such as gold) form an oxide layer on the metal surface; this can be either uneven and porous or uniform, tightly bound and non-porous. http://dentalebooks.com D ental m aterials • 239 Dentine Absorbed light Root canal Enamel Reflected light Refracted light Transmitted light Figure 11.1 Effects of materials on light. Biocompatibility properties and safety procedures Basic principles are that dental materials should: not be carcinogenic; not readily induce hypersensitivity reactions; not produce systemic toxic effects. Wear or degradation products of materials should also not produce these unwanted above effects. Ideally, dental materials should produce no adverse effects on the oral tissues. However, no dental bioma­ terial is entirely biocompatible. Equally importantly, the dentist should be aware, for each material (and their components, e.g. mercury in amalgam, elemental composition of metal alloys) of the following: • • • • relevant safe handling procedures and risk assessments safe disposal procedures health and safety procedures, e.g. COSHH (Control of Substances Hazardous to Health) regulations (Chapter 6). Human Tissue Act (HTA), e.g. storage of extracted teeth (see https://www.hta.gov.uk). The website cites an example: A Dental Teaching Hospital establishes a bank of human teeth to carry out research into tooth erosion, wear and hypersensitivity; and control of dental plaque and staining. The teeth will be donated with consent from the donor after routine dental extraction. The hospital obtains a storage licence from the HTA as well as ethical approval as a research tissue bank. An individual researcher receiving teeth from the bank does not need to make further applications for project specific ethical http://dentalebooks.com 240 • C L I N I C A L D E N T I S T RY approval or for an HTA licence, provided the research project falls within the research aims, material disposal terms, and terms of donor consent specified in the hospital’s research tissue bank ethics approval. In this way, valuable human tissue for research is controlled and made more accessible to a number of research projects. Testing materials Dental materials are subjected to in vitro testing to determine their fundamental mechanical and physical properties. Dentists should be aware of the limitations of in vitro tests and when using new materials should, where possible, examine controlled, long-term clinical trials to determine a particular material’s clinical efficacy (although this is often difficult with the rapid product cycle of dental materials). Systematic reviews and meta-analyses combine the results of several trials and provide high levels of evidence of clinical effectiveness. Problems with testing Materials testing should be to standard specifications and involve both laboratory tests and controlled clinical trials. British (BSI) and International (ISO) Standards are produced to help standardize laboratory testing. This is often difficult to achieve and materials are frequently commercialized prior to their long-term clinical efficacy being established. The product cycle of dental materials is incredibly rapid and dental clinicians should adopt a level of caution and balanced viewpoints when presented with ‘new’ technologies. Materials must be evaluated not only for their final properties but also for: storage properties (e.g. shelf life, need for refrigeration); mixing properties (e.g. ease of mix, time); setting properties (e.g. time, method of set, dimensional and temperature changes). When selecting a material for use in the mouth, it is the clinician’s responsibility to ensure the properties of the material are appropriate to the particular clinical situation. Dental amalgams An alloy of mercury (Hg) with silver and tin. Basic properties Strong, tough material, brittle in thin sections, stoichiometric (intermetallic) phase composition, corrosive potential, no adhesion to enamel or dentine, cheap, simple to use, concerns of biocompatibility, toxicity and environmental effects of Hg disposal, creep, higher http://dentalebooks.com D ental m aterials • 241 thermal conductivity than tooth tissue, higher thermal expansion coefficient compared with tooth tissue (but closer than that of resin composites). Components and metallurgy Dental amalgam is a polycrystalline intermetallic alloy and therefore contains specific stoichiometric phases within its microstructure. Silver (Ag). Provides corrosion resistance, strength, and readily amalgamates (good solubility) with mercury (67–74%). Tin (Sn). Controls setting expansion/contraction and slows the silver/mercury reaction (25–27%). Copper (Cu). Reduces formation of weak and corrosion-prone gamma 2 phase (>12%). Mercury (Hg). Liquid at room temperature prior to amalgamation. Solid residual Hg present in Hg-rich phases following set. Greatest risk of Hg-vapour exposure during placement or removal. Setting reaction (low Cu-content amalgams) Ag3Sn + Hg → Ag2Hg3 gamma (γ ) γ1 + Sn6−8Hg γ2 Setting reaction (high Cu-content single-phase amalgams) Ag-Sn-Cu + Hg → Ag3Sn + Ag2Hg3 ternary alloy γ γ1 + Cu6 Sn5 η Mercury reacts with outer layers of intermetallic alloy particles and precipitate phases form, which are dependent upon solubility. Remnant γ particles exist in the set matrix. In traditional (pre-c.1960) amalgams with Cu-content <6%, formation of γ2 weakened the set material and was prone to corrosion. One example of a contemporary (post-1960) amalgam includes a high-Cu single-composition ternary alloy that eliminates or at least reduces the presence of γ2 thereby substantially improving material properties. Alloy formation Lathe cut. Ingots of solid alloy are turned on a lathe and homogenized. Traditional method. Resists the forces of condensation more effectively than spherical types. Spherical. Spray cooled and atomized in an inert environment. Easier to mix with lower Hg-content, although placement has higher technique sensitivity as particles do not interlock and resist condensation force as with lathe-cut types. ‘Plashy’ consistency on placement. Easier to carve and polish. http://dentalebooks.com 242 • C L I N I C A L D E N T I S T RY Dispersion. Mixture of lathe cut and spherical. Maximizes properties of spherical but with appreciable particulate interlocking for increased condensation pressures. Uses • • Cavities in posterior teeth taking high occlusal loads. Cores (with or without pins) for crowns. Practical tips • • • • • • Mix mechanically to manufacturer’s recommendations. Do not over- or under-triturate. Condense quickly and correctly. Ensure no unsupported enamel in cavity preparation. Use matrices and wedges for marginal control. Use rubber dam for moisture control. Do not polish for at least 24 hours. Safety and biocompatibility Dental amalgam has been widely used for over 200 years. Nevertheless, its use is declining worldwide due to lack of aesthetic tooth mimicry, concerns over its safety and environmental pollution. The operators and patients receiving an amalgam restoration are exposed to mercury vapour during restoration placement, polishing and replacement. Mercury can be released from dental amalgams over the service-life of the restoration; however, these levels are generally thought to be well below the recommended maximum exposure limit. Safety concerns, because of mercury release Cited, and mostly unsubstantiated problems of Hg exposure from dental amalgam, include: Hg-contamination passing across the fallopian tube in pregnant women; multiple sclerosis; central nervous system disorder but no clear evidence. Environment Mercury from crematoria emissions; mercury in the water supply. Dentists should be aware of the increasing Hg toxicity concern of patients and therefore provide advice based on evidence-based publications. If providing alternative treatments then inform patient of the shortcomings that may arise. It is good practice to remove and place amalgam restorations under rubber dam and in a wellventilated room. The Minamata Convention on Mercury was agreed by over 100 countries in 2013, which included the prohibition of a number of mercury-containing products by 2020. This agreement was sparked by an industrial mercury poisoning incident at Minamata Bay, Japan. The World Health Organization have promoted a ‘phase-down’ of dental amalgam, a focus on preventative care and development of http://dentalebooks.com D ental m aterials • 243 alternative materials. The final ratification of the Minamata Convention on Mercury has stated that individual nations can work to gradually scale down the use of dental amalgam. Amalgam allergy (to mercury, ammoniated mercury or amalgam) Rare; lichenoid reactions, often adjacent to amalgams, can be confirmed by patch testing. Disposal Amalgam separators within dental suction apparatus will minimize amalgam entering the water supply and food chains – these have recently been made mandatory in the UK. Waste amalgam should be stored in solution and sent to a recognized waste disposal company for recycling. Resin-based composites The majority of commercial materials based on dimethacrylate resin chemistry (bisGMA/tegDMA), or derivatives (bisEMA/UDMA) and a high volume % of glass fillers. Basic properties No inherent adhesion to enamel or dentine; versatile; light-curable and controllable setting; higher thermal expansion coefficient than tooth; polymerization shrinkage. Components Filler. Strong, hard, brittle filler, e.g. quartz, borosilicate glass, silica. Filler decreases curing shrinkage and decreases thermal expansion. Glass surface undergoes silanization to ensure chemical bond to resin. Barium glasses used for radio-opacity. Resin. Based on bisphenol-A and glycidyl methacrylate (bisGMA or ‘Bowen’s’ resin). Bisphenol-A has aromatic groups which increase stiffness of polymerized chain and decrease shrinkage. Other resins (e.g. urethane dimethacrylate, UDMA) sometimes used. Acrylate diluent present, e.g. TEGDMA tri-ethylene glycol dimethacrylate, as BIS-GMA is very viscous. These diluents increase curing shrinkage. Resin/filler composition affects light scattering, translucency and hence aesthetics. Setting By formation of polymer chains. Reaction can be initiated by: Two paste (base and catalyst system). Reaction between tertiary amine and peroxide; superseded by visible light curing; used occasionally for core materials. http://dentalebooks.com 244 • C L I N I C A L D E N T I S T RY Visible light cure. Uses light reacting with the common 1,2-diketone photointiator, camphoroquinone (CQ: a yellow dye) and a tertiary amine (co-initiator); widely used. There must be overlapping wavelengths of the light source to coincide with the absorption characteristics of the photoinitiator. Other modern resin composite materials may use shorter wavelength initiators to reduce the yellowing effect of CQ and hence the introduction of so-called ‘polywave’ LED (lightemitting diode) curing lights. Resin composite types A broad classification can be based on size of filler particles. Coarse. Large filler particles (>20 µm); reasonable mechanical properties; poor wear resistance; difficult to polish (rarely used today). Heterogeneous microfills. Prepolymerized particles (~5 µm) filled with microfine silica within the resin matrix surrounded by a lower percentage of small filler particles (less than 1 µm) easier to polish although mechanical properties and depth of cure compromised. Hybrid. Contains a wide particle size distribution to improve packing efficiency in order to increase mechanical properties whilst maintaining good polishability. Modern materials often referred to as ‘micro-, or ‘nano-hybrid’, which reflects the decrease in average filler size to <~1 µm Flowable composites. Lower viscosity materials either by reducing filler content or increasing the content of less viscous (diluent) resins. Uses Direct composites Microfills. Class III and V cavities, small Class I cavities Hybrid. Class IV and larger Class I and Class II cavities, core build up Flowable. Repair of marginal defects, liner, initial increment at bottom of approximal box (improves adaptation). Indirect composites Class I and II cavities, composite veneers (hybrid resin). Practical tips • • • • • • • Check shade under daylight conditions. Essential to use rubber dam for moisture control. Use retraction cord for arrest of gingival haemorrhage. Build deep cavities incrementally to achieve full depth cure. Check curing light intensity regularly. Remove the oxygen-inhibition layer after the final increment. Consider selective etching of enamel if self-etch bonding systems are used. http://dentalebooks.com D ental m aterials • 245 Problems with direct composites. Technique sensitive; in general dental practice, reduced longevity compared with amalgam is usually observed although in longitudinal studies involving highly trained operators longevity may even be superior than amalgam; shrinkage and associated shrinkage stress; microleakage; caution in patients with high caries rate; surface finish; radio-opacity; limited depth of cure; placement time doubled versus amalgam. Indirect composites Require two clinical visits. Need to use a dual-cured luting cement. Inlay cured by photocure; then oven or hydropneumatic heat polymerization (120°C, 6 bar pressure for 6 minutes). Improved aesthetics as have time to mix shades. Problems with indirect composites. Microleakage; flash from luting cement; two visits required; difficulties in fixation due to short halflife of free radicals; more expensive; ditch around inlay due to differential wear of softer luting cement. Light curing units The required light intensity for optimum cure of resin-based composites is dependent upon the material. Generally, modern curing units output ~1000 mW/cm2 which would be sufficient to cure a standard 2 mm thick A2/A3 shade in 20 s under ideal conditions. Although exposure duration is relatively short, it is important for the practitioner(s) to protect their own and the patients’ eyes from high intensity irradiation, preferably using blue-blocker (orange) goggles (see practical tips below). Light intensity reduced by debris, bulb ageing, damage to internal filters; therefore it is essential that the output is checked regularly. Further important consideration is required for decreased intensity when curing from increased distances (within limits, curing time can be increased to compensate). Light Emitting Diode (LED). Most commonly available. LEDs have superseded halogen types since the narrow-band emission (~450– 470 nm) circumvents the requirement for an optical filter providing more efficient battery operated devices that have longer output stability. Newer LED types contain multiple diode types to increase the spectral width (important for resin composites that contain combinations of photoinitiators that absorb at shorter wavelengths to improve curing efficiency and lessen yellowing). Halogen. Quartz-tungsten filaments emit broadband white light, which require a filter to provide specific overlap with the photoinitiator (~380–550 nm). Degradation of the filament leads to a reduction in light output intensity over time. http://dentalebooks.com 246 • C L I N I C A L D E N T I S T RY Plasma-arc. High intensity output in an attempt to provide equivalent cure for reduced exposure times. Caution should be exercised with adopting short cure times as a reciprocal relationship between intensity and time may not exist for some extreme combinations and certain (low viscosity) resin material types. Some curing units offer modulated curing functions such as ‘ramped’ or ‘soft-start’ where initial low intensity increases up to a maximum over the irradiation period. Thought to counteract clinical effects of polymerization shrinkage stress, although not clinically proven. Caution should be exercised to avoid under-curing the material. Practical tips • • • • • Regularly check the intensity of the light (using a suitable radiometer). Do not touch the material surface at initial stages of cure to avoid resin adhesion to the tip. Inspect the tip for damage and debris. Cure as close as possible to the material surface and stabilize the curing light. Use orange glasses, rather than paddles for easier stabilization of the light tip. Glass ionomers Developed in the 1960s by Wilson and Kent at the UK Laboratory of the Government Chemist. Typical constituents Fused ion-leachable aluminosilicate glass. Glass is mainly SiO2, Al2O3 and CaF2 and is presented in a powder. Vacuum-dried polyacrylic/ itaconic/maleic (polyalkenoic) acid co-monomer, tartaric acid (to improve handling and snap set), water. Setting reaction Acid–base reaction between glass and polyalkenoic acid consists of three overlapping stages: Dissolution phase. protons displace calcium ions from glass surface, these ions cause initial cross-linking of polyacid chains. Gelation phase. protons displace aluminium ions and these further cross-link polyacid chains. The gelation phase takes about 24 hours, during which physical properties improve. Maturation phase. takes place over weeks and months and involves further cross-linking of polyacid chains by calcium and aluminium ions. http://dentalebooks.com D ental m aterials • 247 Set cement is a composite structure with particles of unreacted glass surrounded by ‘siliceous’ hydrogel embedded in a matrix of crosslinked polyalkenoic acid. Tooth surface pretreatment Many substances have been evaluated as dentine pretreatment agents, e.g. 50% citric acid. In general, pretreatment does not result in worthwhile improvement in bond strengths. Properties Hard and brittle; chemical adhesion to tooth (adversely affected by salivary contamination); susceptible to erosion in first few minutes; increase in surface roughness in mouth over time; low translucency (aesthetics not as good as composite); low abrasion wear resistance; release fluoride ions (some anticariogenic effect); susceptibility to moisture contamination and dehydration. Uses Cervical abrasion and erosion cavities; deciduous tooth restoration; fissure sealing; root surface caries; small Class III cavities; luting cement; Class I cavities in permanent molars/premolars (early carious lesions with minimal occlusal stress); ‘sandwich restorations’ with composite; structural lining. Clinical tips • • • • • Difficult to mix, and powder: liquid ratio critical – consider use of encapsulated forms. Use a matrix where possible. Protect freshly set cement with unfilled resin or varnish. If need to polish, avoid desiccation. Works best in small non-load bearing cavities Resin ionomer hybrid materials These materials have components of both a resin composite and a glass ionomer. Often setting is light cured, chemically cured and has a glass ionomer type set. Light curing is faster than chemical cure. Types of materials Modified composites. Where filler has been replaced by an ion leachable aluminosilicate glass with no acid–base chemical reaction. Compomer (polyacid-modified composite). Where resin has acidic components to generate acid–base chemical reaction but still is mainly set by resin polymerization. http://dentalebooks.com 248 • C L I N I C A L D E N T I S T RY Resin-modified glass ionomers. Powder–liquid materials consisting of a methacrylate resin, a poly acid, an ion leachable glass, water and HEMA (hydroxyl-ethyl-methacrylate). This hybrid material has acid– base, light-cured and chemically cured setting. Properties Improved wear resistance over glass ionomer; improved aesthetics over glass ionomer; fracture toughness greater than glass cermet; less fluoride release than glass ionomers; lower adhesive potential compared with glass-ionomers (compomers require an adhesive layer); increased water sorption especially compomers, which are becoming less popular clinically. Uses Class V cavities; restoration of primary molars; base and liners; currently popular for crown cores. Adhesion and bonding agents Adhesion occurs when two surfaces are held together by interfacial forces – can be molecular attraction or mechanical and physical forces. Micromechanical adhesion Due to surface irregularities and dimensional changes. Can get a strong bond in the absence of molecular attraction, especially under shear forces. Close adaptation of adhesive and surface increases molecular attraction. Molecular attraction So-called chemical adhesion occurs due to ionic, covalent and metallic bonds or van der Waals’ forces. How to achieve adhesion The surface must be clean. The adhesive must exhibit good wetting properties, i.e. the ability to spread over a surface. Preferably, surface energy is increased to provide enhanced adaptation (e.g. surface roughening). The adhesive should exhibit optimal cure (see Lightcuring units, p. 245) and convert from liquid to solid with negligible dimensional change. Factors promoting adhesion Clean surface Increased surface roughness. Improves adaptation by increasing surface area. http://dentalebooks.com D ental m aterials Wettability. Appropriate adhesion. viscosity, hydrophilicity to • 249 enhance Bond type. Micromechanical, chemical and physical bond type. Adhesive cure. Optimal curing is key for successful adhesion. Bonding to tooth tissue Resin composite bonding agents can be broadly classified by the number of procedural steps: Total-etch (etch-and-rinse) 3-step: etch, prime, bond; 2-step: etch, (prime+bond). • • • Etchant: the most common, 37% phosphoric acid used for 15 seconds. Must clean to remove unwanted phosphates. Primer: e.g. HEMA + solvent to improve wettability and transport in moist conditions. Bond: e.g. bisGMA/HEMA or similar resin chemistry as resin matrix in a resin composite material. Self-etch 2-step: (etch+prime), bond; 1-step: (etch, prime, bond) The self-etch primer contains an acidified monomer, e.g. HEMAphosphate, 4-META, 10-MDP. Properties Etch-and-rinse Good long-term clinical data; reliable bond to enamel; removal of smear layer increases incidence of postoperative sensitivity; risk of over-drying dentine following wash and removal of acid, which causes collapse of the demineralized collagen fibril network and reduced bond strength (less effective hybrid layer formation); wetbonding technique to dentine is technique sensitive. Self-etch Smear layer left intact, which reduces postoperative sensitivity; no rinsing of etchant, which eliminates the risk of over-drying prepared dentine; mild (less acidic) self-etch systems have unreliable bond strengths to enamel (consider ‘selective enamel etching’); acidic components absorb more water, which may increase bond degradation; acidic components reduce shelf-life of the material. http://dentalebooks.com 250 • C L I N I C A L D E N T I S T RY Always follow manufacturer’s instructions fully. Avoid confusion with ‘generations’ of bonding systems – there is much overlap in materials chemistry and application between generations. Rapidly changing area and important to keep up to date with the literature. Metal bonding Stages in adhesion: 1. Metal conditioning A rough surface for micromechanical adhesion is needed. This is achieved by sandblasting, chemical etching, electrolytic etching or tin plating. 2. Metal priming Acid-methacrylate resins, which adhere to metal oxide layer, e.g. 4- META 3. Wet surface Unfilled resin. Ceramic bonding Stages in adhesion. 1. Ceramic conditioning Readily etchable ceramics (e.g. feldspathic, leucite, lithium disilicate glasses) by either hydrofluoric acid or acidulated monofluorophosphate. Usually processed in laboratory as hydrofluoric acid very corrosive. Etch pattern (or surface roughening) is limited by high density of modern polycrystalline ceramics (e.g. Y-TZP zirconia, alumina). Tribochemical surface treatments or the use of a phosphate-based monomer (e.g. 10-MDP) has provided some success. 2. Silane coupling Surface-active coupling agents that react with methacrylate in the bonding resin and silica in the porcelain. Enhanced bonding if applied at chairside before cementation. May also be used to enhance retention of fibre posts. 3. Wet surface Unfilled resin. Resin-ceramic bonding can be very useful for repair of ceramics with composite. In addition, ceramic bonding is useful for ceramic veneers, inlays and onlays, ceramic orthodontic brackets and dentine-bonded ceramic crowns. Luting cements, linings and bases Luting cements are setting pastes that retain indirect restorations in teeth. Linings provide a bland thermal barrier. Bases provide a strong barrier and structural lining. Used to give a thermal, mechanical and chemical barrier to dentine. http://dentalebooks.com D ental m aterials • 251 Basic principles All involve acid–base reactions – powder is base; composite when set; no ideal material; different types for different clinical situations. Calcium hydroxide Properties. Can be used as setting or non-setting in different clinical situations; lining sets with salicylic acid or light-cure set; alkaline, pH 9–10; weak material – often requires structural lining; possible antibacterial action; calcific bridge formation. Uses. Dentine desensitizing; indirect pulp cap; direct pulp cap; endodontic intracanal dressing (non-setting); root fractures, perforation, resorption (non-setting); apexification (non-setting); root canal sealer. Zinc oxide-eugenol Composition. Zinc oxide and magnesium oxide, fillers in powder. Eugenol, olive oil and acetic acid in liquid. Properties. Weak; no adhesion to tooth; set accelerated by moisture; can be strengthened by, e.g. polystyrene or acrylic; possible pulpal irritation. Uses. Temporary luting cement; lining; temporary dressing; impression material (edentulous patients). Ethoxybenzoic acid (EBA)-based cements Composition. Based on zinc oxide–eugenol; ortho-ethoxy benzoic acid added; resin added for strength, e.g. polystyrene. Uses. Intermediate restoration; retrograde seal in endodontic surgery (also consider MTA [Mineral trioxide aggregate]). Zinc phosphate Composition. Zinc oxide with about 10% magnesium oxide; phosphoric acid; a crystalline set occurs so set material is fairly opaque. Properties. Long service history; no adhesion to tooth; slight setting contraction; some pulpal effects, so in vital teeth requires lining; exothermic set. Uses. Structural lining; luting cement (especially post cores) • temporary restorations. Zinc polycarboxylate Composition. Mainly zinc oxide with freeze-dried polyacrylic acid and trace of fluoride; on setting, zinc ion cross-links polymer chains; some adhesion to tooth via a chelate, possibly calcium polyacrylate. http://dentalebooks.com 252 • C L I N I C A L D E N T I S T RY Properties. Some adhesion to tooth; non-irritant to pulp; opaque; more soluble than zinc phosphate. Uses. Luting cement; structural lining; temporary restorations. Glass ionomers and resin-modified glass ionomers Widely used as luting cements, structural linings. Temporary cements and restorations Temporary cements Must be strong enough for short-term retention of a restoration but weak enough for easy removal by the dentist. Usually use zinc oxide– eugenol or non-eugenol-containing cements. Occasionally may need stronger temporary luting cement, e.g. for high occlusal loads. Often choose zinc polycarboxylate with lower powder: liquid ratio. Can use temporary cements to ‘try in’ definitive restorations by making them non-setting, e.g. proprietary brands or zinc oxide with petroleum jelly. Temporary restorations Must withstand occlusal forces for several weeks, easy to remove and have low thermal conductivity. Usually use zinc oxide–eugenol. Can be strengthened with polystyrene. For more intermediate restoration can use ortho-ethoxy benzoic acid containing material which has better wear resistance than zinc oxide–eugenol. Other temporary restorations Gutta-percha Natural rubber contorted polymer chain based on cis-polyisoprene. Properties. Include easy distortion, poor adaptation to cavity margins, needs pressure for insertion. Used occasionally as temporary restoration but much more commonly for root canal obturation. Temporary putties EBA or eugenol based single pastes which harden on contact with moisture. Usually used as access cavity temporary restorations in teeth undergoing root canal treatment. Some use in patient-applied commercial ‘dental emergency kits’. Impression materials Properties of ideal material Should be: accurate; dimensionally stable; biocompatible; easy to mix; short working and setting times. http://dentalebooks.com D ental m aterials • 253 Classification Rigid 1. Impression compound 2. Zinc oxide–eugenol Elastic 1. Hydrocolloids – Reversible (agar) – Irreversible (alginates) 2. Elastomers – Polysulphides (addition/condensation curing) – Silicones – Polyethers Rigid impression materials Cheap; relatively weak; used for edentulous impressions, i.e. where no undercuts present. Impression compound Type I low fusing. Used for primary edentulous impressions. Type II high fusing. Used for peripheral adaptation of edentulous and dentulous individual trays. Admix – 3 parts per weight of Type I and 7 parts per weight of type II. Composition. Thermoplastic resins and waxes; lubricants, e.g. stearic acid; fillers, e.g. pumice. Properties. Thermoplastic; poor accuracy; distortion and memory effects; cheap. Clinical tips Heat in warm water. If too hot will stick to teeth. If too cool will not distort sufficiently. Zinc oxide–eugenol Zinc oxide–eugenol based. Adheres to denture acrylic, so is useful for relining/rebasing impressions. Slowly becoming obsolete as silicones are vastly superior. Properties. Setting accelerated by moisture; accurate; use with close-fitting individual tray; irritant to oral mucosa. Occasionally impression waxes can be used to correct minor faults in impressions made with impression paste. Such waxes require a high flow at body temperature. http://dentalebooks.com 254 • C L I N I C A L D E N T I S T RY Elastic impression materials – hydrocolloids Hydrocolloid is so-called as ‘hydro’ (water) is used as a plasticizer and ‘colloid’ (initial polymer is colloidal in size – approximately 0.2 mm diameter). Two types of hydrocolloids: reversible (agar) and irreversible (alginate). Setting reactions. From a sol to a gel by particles forming fibrils which cross-link. If cross-linking and fibril formation involves van der Waals’ forces alone, is reversible; if in addition involves ionic forces, is irreversible. Set gel is weak – so need fillers to strengthen gel. Properties Hydrocolloids exhibit poor dimensional stability caused by: Syneresis. Continued cross-link formation after initial set so impression shrinks and water is forced out; happens almost immediately. Imbibition. Impression swells as water is imbibed by osmosis due to presence of electrolytes between polymer chains. Evaporation. Water evaporates so impression shrinks and becomes hard and brittle. Clinical tips • • • Place damp gauze over impression to decrease syneresis Pour impressions as soon as possible to decrease effects of imbibition and evaporation Disinfect impressions prior to sending to laboratory. Reversible hydrocolloid Agar. Sulphated polysaccharide. Agar is accurate but also has poor dimensional stability. A water bath is required to convert from sol to gel phase. Mainly used in the dental laboratory for duplicating casts. Irreversible hydrocolloid Alginate. Carboxylated polysaccharide based on alginic acid. In widespread clinical use. Gels by cross-link formation with calcium ions. Composition. Sodium alginate; calcium phosphate; sodium sulphate (retarder); fillers, e.g. zinc carbonate; some contain pH indicators (chromatic alginates); change colour – pH drops as gel forms. http://dentalebooks.com D ental m aterials • 255 Available in different viscosities depending on need for accuracy (low) or self supporting (high). Elastic impression materials – elastomers Basic types • • • • polyethers polysulphides addition silicones condensation silicones. Amount of filler present determines heavy, regular and light bodied material. Polyethers A polyether is a polyimine and is self cross-linking. Composition. Base and catalyst pastes both containing plasticizer and filler. Catalyst is usually an aromatic sulphonate ester. Properties. Rigid when set (difficult to remove from large undercuts); dimensionally stable (can absorb water); hydrophilic; strong; automated mixing machine simpler than manual mix. Uses. Crown and bridge impressions; cobalt–chromium denture impressions; implant impressions. Polysulphides Contains a prepolymer which has a sulphur bridge, an ether link and an ethyl group (plasticizer). Sets by cross-linking when oxidized using lead peroxide catalyst. Properties. Accurate; high tear strength; set accelerated by moisture; moderately hydrophilic; long set-time (~10 mins); poor medium-term dimensional stability (cast in first 24 hours); noxious odour (free mercaptan groups); stains clothes. Uses. Crown and bridge impressions; cobalt–chromium denture impressions; implant impressions; master edentulous impressions; particularly useful for multiple preparations. Addition silicones Based on dimethylsiloxane, which polymerizes by addition to an unsaturated end group via a complex platinum-based catalyst. http://dentalebooks.com 256 • C L I N I C A L D E N T I S T RY Properties. Accurate; dimensionally stable; not as strong as other elastomers; surfactants required to improve hydrophilic properties; fairly quick setting time. Uses. Crown and bridge impressions; cobalt–chromium denture impressions; implant impressions; master edentulous impressions; particularly useful for one or two units of crown and bridgework (setting time can be a problem for multiple preparations). Addition silicones are the most commonly used elastomer-type impression materials. Condensation silicones Based on dimethylsiloxane, which polymerizes to polydimethylsiloxane, which acts as an alcohol. This undergoes transesterification with tetraethylsilicate (acid), releasing ethanol (i.e. condensation). A fatty acid salt catalyses the reaction. Properties. Shrinks on curing; loses ethanol on storage; surfactants required to improve hydrophilic properties; intermediate tear strength. Uses. Crown and bridge impressions; maxillofacial prosthetics; use declining as superseded by other elastomers. High viscosity silicones (Lab Putty). Used for duplicate dentures or for silicone index to assist in setting of teeth or assessing changes in casts. Remember the relative advantages and disadvantages of the different impression materials – important to select the correct material for the clinical situation in question. Dental ceramics Modern dental ceramics can be broadly classified by the quantity of crystalline components: 1. Predominantly glass include traditional feldspathic porcelains; mainly an amorphous glass network; use of network modifiers (metal oxides) to adjust firing temperature, thermal expansion, viscosity, translucency; low fracture toughness; brittle; wear resistant. 2. Particle filled ceramic composites glass network with crystalline filler particulates, e.g. albite ~40% (Vita Mark II), leucite ~40–50% (Empress Esthetic, Mirage), lithium disilicate (glassceramics), alumina ~70% (e.max Press, e.max CAD, In-Ceram http://dentalebooks.com D ental m aterials • 257 alumina); provide reasonable translucency; improved fracture toughness; low-medium strength. 3. High-density polycrystalline little, or no glass component, e.g. yttrium-stabilized polycrystalline zirconia ~99%, polycrystalline alumina ~99%; CAD/CAM (computer-aided design and computer-aided manufacturing) processed; low-medium translucency; usually veneered with a low-crystalline content glass (specific cooling rates must be applied to prevent delamination/chipping); full-contour zirconia ceramics available; high strength; indicated for multiple-unit bridgework. Dental ceramic processing Traditional processing. Crowns and bridges are individually made in a laboratory. First, an opaque core and then progressively glassier layers of porcelain are applied to mimic dentine and enamel. Tints can be applied to mimic cracks, gingival staining, irregularities, etc. Laboratory handling ~30% shrinkage on firing; vibrate and blot reduces shrinkage to ~10%; vacuum fired; pressure cooling and slow firing reduces porosity; self-glaze using short post-process firing; slow cooling rates are critical to prevent residual stress between ceramic layers and consequential crack formation under tension. Slip-casting. Involves a technically challenging approach to ceramic manufacture, e.g. In-Ceram alumina; partial sintering of a porous alumina core; infiltration of lanthanum glass into the porous substructure; ~70% crystalline; interpenetrating-phase ceramic composite (no isolated phase, lower strength than high-density polycrystalline ceramics but similar fracture toughness); can also be provided as a pre-formed block for computer-aided machining. Hot-pressing. Uses a traditional lost-wax technique; softened particle-filled ceramic (often lithium disilicate, e.g. e.max Press) pressed into a heated investment mould; reduced shrinkage, although veneering porcelain requires over-contouring. CAD-CAM. Computer-aided design and manufacture uses a subtractive method of machining; modern systems may include intraoral cameras for data capture (‘optical impressions’); computer designed restoration milled from a pre-formed ceramic blank (polycrystalline, lithium-disilicate or silicate-based ceramics); usually milled in a partially-sintered state, final firing shrinkage compensated by oversize die. Metal–ceramic crowns Ductile metal core often based on nickel–chrome, high and low gold or silver–palladium alloys. Porcelain adhesion to metal achieved by http://dentalebooks.com 258 • C L I N I C A L D E N T I S T RY ceramic melting and wetting metal surface in a vacuum. Requires a high melting metal with matching thermal properties to porcelain. Acts as a laminated composite so any cracks present cannot propagate. Poorer aesthetics as ‘metal shines through’. Good for ‘tight occlusions’ as can have metal palatal surfaces to crowns which are thinner than porcelain. Uses of dental porcelain: crowns and bridges; veneers; adhesive crowns; inlays and onlays; inserts within direct composites; denture teeth. Aesthetics Crown aesthetics are very important as a crown must mimic how light is reflected, refracted, transmitted and absorbed through a natural tooth (see Figure 11.1). The dentist must select shades for crown restorations. This is usually based on the three-dimensional Munsell Colour System: Hue – family, e.g. red, green, blue. Chroma – intensity, i.e. the amount of hue. Value – brightness or dullness. Problems in choosing shades Metamerism. Objects appear as different colours in different lights. Colour washout. An object stared at for too long a time appears lighter. Observer errors. Different people are ‘better’ than others at shade selection. Technical problems. Different technicians and laboratories produce ‘different shades’ for same operator choice. Electronic shade guide systems are also slowly being introduced to reduce some of the subjectivity in shade taking. Tips for choosing aesthetic shades • Communicate clearly to technician, e.g. map different shades for one crown • Choose shades under natural daylight (choose surgery lighting that uses tubes as close to this as possible) • Stare only briefly at object then rest eyes by looking at a grey object • Ensure you are not colour blind • Involve dental nurse or technician in shade selection for ‘second opinion’ • In difficult cases consider use of photography to communicate with technician http://dentalebooks.com D ental m aterials • • • • 259 Recent development includes use of colour-corrected digital imaging systems Take great care when choosing shades for individual central incisor crowns and crowns next to dentures Do not permanently cement a crown if the patient is dissatisfied with the shade. Casting and wrought alloys Basic metal microstructure A metallic bond is non-directional so as atoms cool from a melt, crystals form. Metals are crystalline. As many nuclei form during cooling, metals are polycrystalline. Crystals grow inwards in a melt and have various shapes. Crystals are called grains and meet other crystals at grain boundaries. Crystals grow from a nucleus dendritically. Pure metal atoms are close packed and form one of many types of crystalline lattices. Metal lattices Alloys are combinations of metals in solid solutions. An alloy is often harder due to solution hardening. Alloy metals can combine by precipitation, crystallization or immiscibility in solid solution, depending on the metals involved. Two basic types of alloys Interstitial solid solution. Here a very small atom is in the basic lattice space and does not really alter the lattice but stops dislocation, e.g. steel (carbon and iron). Substitutional solid solution. An atom of one metal replaces a lattice atom of another metal, distorting the lattice and altering properties, e.g. dental gold (gold and copper). Altering metal properties Metal properties can be altered by mechanical, chemical or heat treatment processes. Work hardening. Metal crystals are imperfect and ductility can be adjusted due to linear defects called dislocations. When a metal is worked, e.g. tightening a cast clasp, dislocations accumulate at grain boundaries and microcracks form, the cracks propagate and the metal becomes brittle and work hardened. Annealing. This can reverse work hardening by heating the metal to encourage stress relief, recrystallization and grain growth. http://dentalebooks.com 260 • C L I N I C A L D E N T I S T RY Cooling. Slow cooling gives larger grains which have fewer boundaries and are softer. Fast cooling gives smaller grains, more boundaries and produces a harder metal. Polishing. During polishing, metal atoms are smeared over the surface in a random way, which looks amorphous under a microscope but is aesthetically pleasing. Etching. Surface etching causes crystals to be etched in different directions. Produces poor aesthetic appearance but improves area for bonding. Oxide layer. Many metals have an oxide layer on their surface. This can be seen as a tarnished surface. Some metals have an oxide layer which is tightly bound to metal and is useful for adhesion to porcelain or resin cements. Appropriate metals are incorporated into dental alloys so that an optimum oxide layer for bonding is produced by controlled surface oxidation. Dental gold alloys Composition. Basic gold and copper. Copper causes order hardening. Achieved by slow cooling then reheating. Copper causes gold to be red in colour. Other metals are introduced in small quantities to lighten the material, e.g. platinum, palladium, silver. Properties. Biocompatible; good corrosion resistance; easy to cast; aesthetically appealing; ductility and hardness dependent on type of gold alloy chosen. Uses. Use of cast gold alloys depends on type: Type I. Class III or V inlays. Type II. Most inlays. Type III. Crowns/bridges. Type IV. Posts and dentures. White gold. Contains silver and palladium. White or pale yellow in colour. Used in crown and bridgework and is harder but more difficult to cast. Cobalt–chromium alloys Composition. Cobalt 40–60%; chromium 25–35%; small amounts of nickel (improves ductility); carbon (hardens); iron (solution hardening); molybdenum (refines metal grains). Properties. Strong and hard; high corrosion resistance; little ductility; very work hardenable; less expensive than gold; ×2 casting shrinkage compared with gold; less flexible than gold; does not bond to porcelain. http://dentalebooks.com D ental m aterials • 261 Due to low ductility and work-hardening, do not bend a cobalt–chromium clasp or it may break (due to brittle grain boundary carbides). Uses. Partial denture bases and clasps. Nickel–chromium alloys Composition. Nickel 70–80%; chromium 15–20%; trace metals. Properties. Bonds to porcelain; casting accuracy; ductile; not as strong as cobalt–chromium; nickel is a possible carcinogen and common allergen. Uses. Crown and bridgework. Steel alloys Composition. Iron and carbon alloy system where carbon acts as a metal in an interstitial position in the iron lattice. Steel contains less than 2% carbon. Steel may be brittle or ductile depending on heating and quenching. Types Martensite. Hard and brittle but not corrosion resistant; used for scalpel blades, some surgical tools and dental hand instruments. Stainless steels. Austenitic steel of two types: 18/8 (18% chromium/ 8% nickel) and 12/12 (12% chromium/12% nickel). These have good corrosion resistance and can be used intra-orally as clasps in orthodontic appliances or dentures. Denture base materials Two types • polymer based • metal based – cobalt–chromium. Polymer denture base materials Composition. Come in powder and liquid form. Powder. Polymethylmethacrylate granules, benzoyl peroxide. Liquid. Methylmethacrylate, ethylene glycol dimethacrylate. Curing reaction. Cure occurs in several stages: 1. Granular: particles are wetted. 2. Stringy: particles become tacky. http://dentalebooks.com 262 • C L I N I C A L D E N T I S T RY 3. Dough: molecular entanglement begins. 4. Rubber: complete molecular entanglement. Cure is exothermic. 20% shrinkage in volume. Can be heat cured (above peroxide decomposition temperature) or cold cured (addition of amine causes peroxide to decompose at room temperature). Because of curing shrinkage, mould is overpacked and pressurized. Typical heat cure prewarms to 60°C then 70°C and up to 100°C over time – reduces residual monomer and decreases porosity. Cold cure leads to increased porosity and yellowing due to amine. Properties. Poor impact resistance; moderate strength; generally non-toxic; low density; cheap; easy to process; not radio-opaque; poor thermal conductivity; weak in thin section; poor wear resistance; easy to add to, permitting ease of repair, reline or addition. Uses. Dentures; orthodontic appliances; individual impression trays. Developments High-impact acrylics. Have co-monomers and rubber fillers. Radio-opacity. Heavy metals or halogenated compounds but weaken material. Bonding to cobalt–chromium. Can be improved by mechanical mesh, silicoating or metal conditioning. Methacrylate sensitivity. Although rare, can be a problem in some individuals. Alternative denture base materials Polycarbonates. Have to be injection moulded. Nylon. Absorbs water and distorts denture. Used in conjunction with porcelain teeth. Enjoyed a resurgence in denture construction due to the ‘flexible’ nature. Able to utilize undercuts. Not easy to polish and may damage teeth by excessive coverage of soft tissues. Soft linings Temporary Polyethylmethacrylate gelled with ethanol. Ethanol is leached and lining often hardens. Uses. Functional impressions; temporary linings to immediate dentures; as a tissue conditioner following surgery (especially implant surgery). http://dentalebooks.com D ental m aterials • 263 Permanent Silicone, modified acrylic or polyphosphazine based. Adhere to acrylic with difficulty, attract bacteria. Uses. Obturator; denture support problems. Endodontic materials Materials used in endodontics can be classified as: root canal cleansers; preformed root canal fillings; root canal sealers; retrograde root filling materials; intra-canal medicaments. Root canal cleansers Sodium hypochlorite. 1–5%, antibacterial action in the canal by release of chlorine. EDTA (ethylenediaminetetraacetate) solution. 17%, chelating agent that removes smear layer. EDTA and urea peroxide. Releases nascent oxygen, which leaves environment unsuitable for anaerobes and lifts debris from canal. Lubricates canal. Chlorhexidine. Antibacterial. Preformed root canal fillings Gutta-percha cones. Isomer of natural rubber with an isoprene unit. At room temperature, gutta-percha is 60% crystalline (crystals of transpolyisoprene) and 40% amorphous. Contains inert zinc oxide filler and antioxidant, which reduces brittleness. Available in either standardized (sizes compatible with files) or non-standardized cones. Gutta-percha becomes soft at 65°C and melts at 100°C. Heated gutta-percha. Various techniques. Uses alpha gutta-percha, which is more tacky and flows easier than conventional beta gutta-percha. Silver points. 99.8% pure silver. Corrosion is a problem and not used but may be seen in older patients. Root canal sealers Zinc oxide–eugenol based. Contain setting retarders to increase working time and barium sulphate for radio-opacity. Often have resin to reinforce the sealer. Calcium hydroxide based. Hygroscopic, antibacterial. Glass ionomer based. Some bonding to dentine, smear layer removal. Dentine bonding agents. Epoxy-based resin sealer. Very slow setting. http://dentalebooks.com 264 • C L I N I C A L D E N T I S T RY Formaldehyde-containing sealers. Fix tissue. Problem if escapes into periapical tissues. Have no place in modern endodontics. Retrograde root filling materials • • • • Modified zinc oxide–eugenol-based cements Ethoxy benzoic acid Hydroxyapatite and similar materials Mineral trioxide aggregate (MTA). Intra-canal medicaments These should not be used as there is no evidence they provide any advantage over conventional biomechanical cleaning of the canal, and they may be irritant. Implant materials Types of implants (Chapter 12) • • • Subperiosteal Transmandibular Osseointegrated. Subperiosteal Used rarely nowadays. For edentulous mandible only. Involves impression of bone after flap raised, manufacture of a casting with parallel copings made from castable titanium, which sits under the periosteum. Transmandibular Used rarely for very atrophic edentulous mandibles only. Made from gold in a rigid box frame. Osseointegrated Most common implant in current use (Chapter 12). Uses. Single tooth replacement; edentulism; partial edentulism. Osseointegration is a direct and functional connection between ordered, living bone and the surface of a load-carrying implant. Commercially pure titanium. Most commonly used material. In form of hollow cylinder. ‘Fracture healing’ between implant and bone. Capable of bearing load 3–6 months after insertion of implant depending on oral site. In some instances immediate loading is possible. http://dentalebooks.com D ental m aterials • 265 Properties. Titanium oxide is chemically inert; biocompatible; strong; high dielectric constant of titanium oxide. No evidence that any surface treatment is superior to others Other materials used for osseointegration Titanium alloys. Less good results. Plasma-sprayed surface to titanium. Increases surface area. Aluminium oxide. Good for immediate tooth replacement but poor mechanical properties. Miscellaneous Waxes Waxes occur naturally from animal, mineral and plant sources. In addition, some distillation products of petroleum may exist as a wax (e.g. paraffin wax). Addition of natural gums and resins may give wax adhesive properties. Dental waxes are a combination of natural and synthetic waxes. Types of wax in dentistry Inlay wax. 40–60% paraffin wax, maximum flow at 45°C. Sheet casting wax. Used for wax patterns in laboratory. Sticky wax. Hard, brittle and adhesive – used in laboratory for locating casts, etc. Carding wax. High flow at room temperature so can be hand moulded. Good for boxing impressions before casting. Modelling wax. 70–80% paraffin wax. Flows at 50–58°C. Used extensively in denture construction for record blocks, jaw registration, etc. Shellac resin. Thermoplastic; high in fillers; good as baseplate in denture construction as stable at mouth temperature. Fissure sealants Properties of ideal sealant. Adhesion between enamel and sealant; need flow of sealant into pits and fissures; sufficient strength and wear resistance to withstand occlusal forces. Materials used for fissure sealing. BIS-GMA resins, glass ionomer cements. It is absolutely critical when fissure sealing to ensure that caries is not present in the fissure. http://dentalebooks.com 266 • C L I N I C A L D E N T I S T RY Periodontal materials Periodontal pack or dressing. Two-paste zinc oxide–eugenol system. Uses. Post surgery when bone exposed, protects wound surface from mechanical trauma; prevents excessive granulation tissue formation; provides a physical barrier to bacterial contamination; used mainly after gingivectomy, apically repositioned flaps and free gingival grafts. Investment materials These are used in lost wax processes, e.g. metal casting, denture bases. Properties. Withstand high temperature; set at room temperature; expand slightly to compensate for casting shrinkage; reproduce detail; porous to let gases escape; strong. Types of dental investment Low temperature. – gypsum bonded. Used for gold casting. High temperature. – phosphate bonded: silica bonded. Used for cobalt–chromium casting. Lost wax processes often involve addition of a sprue or vent to release gases from the mould. This is particularly important in silicabonded investment, which is the least porous. Polishing Polishing involves surface restructuring and surface loss or abrasion. Abrasion polishing Using successively finer abrasives reduces scratch width to below wavelength of light. In addition, it produces surface restructuring by either transfer of high spots to low spots or, in metals, creation of finer crystal grains, so surface is virtually amorphous. Polishing abrasive must be harder than surface to be polished. Relief polishing Surfaces of varying hardness polish in relief, i.e. hard bits stick out of surface. This is undesirable and is why microfine composites with smaller particles polish better and have superior aesthetics than composites with coarse particles. http://dentalebooks.com D ental m aterials • 267 Temporary crown materials Properties. Cheap; moderate strength; reasonable aesthetics; set easily and quickly; non-adhesive to tooth; often use cartridge mixing systems. Materials in use Epimine polymers. Based on bis-phenol A and polyether rubber; highly translucent, low shrinkage. Polyethyl or polybutyl methacrylate. Fairly high shrinkage on setting, good aesthetics. Composite. Good aesthetics, often different shades available. Preformed polycarbonate crowns. Good aesthetics for anterior teeth. Preformed stainless steel crowns. Good for full veneer crown preparations on posterior teeth. Denture teeth Types Acrylic. Injection or dough moulded; acrylic is highly cross-linked for greater wear and surface characteristics, can lead to debonding problems from denture base; can surface stain teeth for better aesthetics. Most teeth are acrylic. Porcelain. Mechanical attachment to denture base via diatoric hole or pin; use nowadays limited to acrylic allergy or highly demanding aesthetic problems; less abrasion than acrylic teeth. Current ‘growth areas’ in dental materials There is active research in all areas of dental materials, and considerable attention on: • • • • • New thiolene resin chemistries to reduce shrinkage stress of resinbased composites So-called ‘bulk-cure’ resin-based composites with high curing depth Interpenetrating phase composite ceramics for modified defect populations Robocasting/3-D Printing of models, alloys and ceramics Optimizing milling precision of current computer-aided design ceramics http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Implantology Introduction 269 Dental implant materials 269 Restorative aspects 274 Prosthesis design 276 12 Surgical aspects 279 Maintenance 284 Current developments in implant treatment 286 Introduction In the past 30 years, the field of implant dentistry has significantly developed. Today, dental implants are routinely used in everyday dental practice and provide a useful treatment modality for the oral rehabilitation of patients. However, it is important to emphasize that whilst dental implants are increasingly popular with both den­ tists and patients, they should not be considered as a tooth substitute but rather a treatment modality for replacing missing teeth. At the time of going to print, the General Dental Council (GDC) is seeking views on how it regulates the practice of implant dentistry. The Council supports the Training Standards in Implant Dentistry, pub­ lished by the Faculty of General Dental Practice (UK) and expects education providers and dentists who wish to practise implant den­ tistry to refer to these standards as the authoritative source of train­ ing standards for implant dentistry. The standards describe the minimum level of training and assessment that a dentist would be expected to have obtained prior to carrying out implant treatment from either a surgical or restorative aspect. Specialist referral should be considered in cases that may be beyond the general dentist’s train­ ing or experience. Currently, some dental schools are introducing this topic to undergraduates. The competencies in relation to implant dentistry at under­ graduate and postgraduate level have also been defined by the ADEE (Association for Dental Education in Europe) and the EFP (European Federation of Periodontology) in two separate consensus conferences. The GDC has yet to recognise it as a specialty. Dental implant materials (see also Chapter 11) Types of dental implant • • Historic: Subperiosteal – Blade – Ramus frame Contemporary: Endosseous (within bone); subdivision – tissue level or bone level http://dentalebooks.com 270 • C L I N I C A L D E N T I S T RY Subperiosteal. Used rarely and considered obsolete by many. However may (rarely) be encountered in older patients. Not osseointe­ grated, cast metal frame with transmucosal elements placed directly onto bone below periosteum. Blade. Wide, thin titanium or titanium alloy open frames inserted vertically into narrow bony ridge with integral transmucosal element. Used rarely and considered obsolete by many. Ramus frame. Cast metal frame employing a combination of blade inserted into ramus and subperiosteal element anteriorly. Used rarely and considered obsolete by many. All of the above are ‘legacy’ dental implants designed to be used in atrophic edentulous mandibles (and in some cases maxillae, subpe­ riosteal type only); however, the surgical procedures required for their placement is considerably invasive. Complications are difficult to manage. The high success rates achieved with micro-roughened endos­ seous implant surfaces and also with shorter implants, together with predictable bone regeneration techniques, render these former types of dental implant inappropriate. Osseointegrated. The most common type in current use. Root-form implant placed into a precise endosseous osteotomy. Osseointegration is ‘a direct and functional connection between ordered, living bone and the surface of a load-carrying implant’ (Figure 12.1). Uses Titanium endosseous implants were developed following a serendipi­ tous discovery by Per-Ingvar Branemark. Originally designed for use in edentulous mandibles only, now are commonly used in single and multiple tooth replacement in partial edentulism and to treat com­ plete edentulism. Materials 1. Commercially pure titanium: Normally grade 4 commercially pure titanium (CPT4), cold worked (CPT4(cw)) to increase tensile Figure 12.1 Single tooth implant replacement. © Institut Straumann AG, 2011. All rights reserved. By courtesy of Institut Straumann AG. http://dentalebooks.com I m p lant o l o g y • 271 strength (TS) and reduce risk of fracture. TS CPT4 = approx. 550MPa, CPT4(cw) 830MPa. 2. Titanium alloy: Alloy of titanium, aluminium and vanadium (Ti6Al4V). Used commonly by some manufacturers as greater strength at reduced manufacturing cost (TS approx. 930MPa). Adverse effects from aluminium and vanadium have been dem­ onstrated at cellular level although the clinical significance is yet to be agreed. Non-homogenous crystalline structure with surface harness too high for acid etching (see implant surfaces, below). 3. Titanium-Zirconium alloy: Newer alloy with high tensile strength (TS approx. 970MPa) and good biocompatibility; homog­ enous crystalline structure allows acid etching for improved bone healing reponse. 4. Zirconia: Non-metallic, highly biocompatible, and white in colour with some consequent aesthetic advantages. They are a one-piece implant requiring accurate placement and may undergo phase changes in crystalline structure under load leading to frac­ ture and difficulty in removal. They are not used extensively and do not have long-term follow-up data. Surfaces 1. Titanium is highly reactive to oxygen and thus, the surface of a pure titanium implant is chemically inert and very biocompatible. 2. Smooth machined implant surfaces have been largely superseded by micro-roughened implant surfaces, which demonstrate better initial osseointegration and an increase in osseointegrated surface area. 3. Titanium plasma sprayed surfaces and other macro-roughened surfaces have largely been abandoned, as have coated implants. 4. Micro-roughened implant surfaces such as those achieved with sandblasting and acid etching may influence cellular differentia­ tion and proliferation; the accelerated osseointegration and increased bone to implant contact that may be achieved allows functional loading of the implant at an earlier stage, which for some implant systems may be in approximately 6–8 weeks. Connection 1. Two-piece implants have a connection with a transmucosal element used to support the prosthesis called an abutment. The connection can be either external or internal. 2. Most implants now employ an internal connection with a conical seal, which has less micromotion and less tissue irritation. However, external implant-abutment connections are still avail­ able in some implant systems. 3. Some implants have a one-piece design, such as ‘mini-implants’ used for temporary use or the stabilization of lower complete http://dentalebooks.com 272 • C L I N I C A L D E N T I S T RY dentures. One-piece implants are also not always adaptable to later needs as the patient ages or if complications occur. Platform Dental implants may come in different diameters (‘body sizes’) and may have varying sizes of restorative platform to accommodate dif­ ferent tooth sizes. However, it is generally accepted that the proper planning process is to select the implant size and position based on the proposed (prosthetically driven) restoration and not merely by reference to the available bone volume. Clinical use of dental implants Dental implants are one of the possible options for replacing missing teeth and in certain individuals may provide significant advantages as a treatment option. The treatment may require multiple visits for the completion of the surgical and prosthodontic stages, so it is important that the patient is well informed and aware of all treat­ ment steps as well as the advantages and disadvantages of implants. All restorative alternatives should be presented to the patient during the final planning of the treatment. Clinical experience, appropriate training leading to proper treatment planning, and good case selection are critical factors in successful implant treatment. It is particularly important for dentists undertaking implant treatment to undertake relevant continuing professional development (CPD) given the rapid changes taking place. Uses Dental implants may be used to support many forms of prosthesis: • • • • • Overdentures, complete or partial Single crowns Multiple individual crowns Fixed bridges (fixed partial denture, FPD) Craniofacial prostheses, including obturators. Case selection There are few absolute medical contraindications to the placement of dental implants, but there is a plethora of important considera­ tions that have to be taken into account. Close co-operation between http://dentalebooks.com I m p lant o l o g y • 273 periodontist, prosthodontist and possibly other dental specialties may be required in advanced/complex cases. The basic principles of treat­ ment planning include: • • • • • • • • Understanding the patient’s compliance and expectations, and managing the latter. Assessing the reasons for tooth loss, previous treatment, and reasons for failure, and any familial factors such as susceptibility to periodontal disease. Any known risk factors for implant loss or biologic complications must be controlled prior to the initiation of the treatment. Determining any systemic medical conditions that may impact (negatively) on implant success. Obtaining a social history including smoking and other habits, alcohol intake, occupation, mobility, access to treatment and on-going maintenance care. A complete and comprehensive dental assessment including: • Extra-oral examination for asymmetry, lymphadenopathy, TMJ problems, lip support, smile height. • Intra-oral soft tissue examination to exclude systemic disease, oral mucosal conditions, etc. • Periodontal assessment including six-point pocket charting, plaque and bleeding score, tooth wear, tooth mobility, occlu­ sion, crowding, etc. • Assessment of edentulous ridges – bone height and width, volume and width of attached mucosa. • Tooth-by-tooth prognosis assessment in terms of caries, endo­ dontic status and condition of exiting restorations; the impending loss of other teeth can significantly affect the optimal treatment plan. Assessing the patient’s ‘treatment’ wishes and expectations as well as their ability to comply with the requirements of treatment and with the necessary oral hygiene procedures and smoking cessation before treatment. Radiologically assessing using plain radiography as the first-line investigation, the remaining teeth, local anatomy and structures to be avoided, and other pathology. (See Radiological investiga­ tions, in the section on Restorative aspects, below) Considering all the relevant options for tooth replacement, which must be explained to the patient and followed up in writing. (See Consent, below) Consent Implant treatment is a non-essential, elective, invasive surgical pro­ cedure and like all surgical procedures there is a risk of complications http://dentalebooks.com 274 • C L I N I C A L D E N T I S T RY and harm. Continuing informed consent is therefore mandatory and must include sufficient, relevant information to enable the patient to make a fully informed decision. Such information may include: • • • • • • • A written, individualized treatment plan for each patient, outlin­ ing the proposed treatment and intended benefits, likely and pos­ sible risks with any on-going consequences, anticipated costs, and all suitable alternative treatment options with comparative ben­ efits, risks and costs. The patient must be aware of any biomaterials that are to be used and the nature and origin of such materials. Such a treatment plan should be provided well in advance of surgery and the patient should have the opportunity to discuss the treatment and ask questions. The patient should be asked to sign the treatment plan to indicate their acceptance and understanding of the proposed treatment and costs. Valid informed consent is crucial. Each stage should be explained at the time of the procedure; for surgical procedures a written consent form is advisable, detailing the nature and purpose of the procedure with possible risks. Any changes in the plan that arise as treatment progresses should be explained, documented and confirmed in writing to the patient. A simple, signed print-out of a computerized list of costs commonly provided from proprietary dental software packages does not constitute valid consent. Restorative aspects Restorative planning The consideration of the intended restoration always precedes surgery. Whilst surgical considerations may mandate changes to the restorative plan, this should occur before surgery (when possible). It is not good clinical practice to place implants into the available bone volume and later decide on the design of restoration following their integration. The principles of ‘prosthetically driven implant place­ ment’ have been well established and mandate that the position of the implant is determined by the proposed restoration. The normal process of planning is as follows: • • • • Agree proposed final restoration (fixed, removable, etc.) Fabricate a diagnostic preview of the proposed restoration Select appropriate implant positions for loading Select appropriate implant platform for each site based on pro­ posed restoration http://dentalebooks.com I m p lant o l o g y • • • • • • • 275 Select appropriate implant diameter based on proposed restoration Fabricate a radiographic template (see Investigations) Obtain appropriate radiological imaging Consider correction of bone deficiencies at proposed implant site(s) if necessary OR revise plan Confirm implant positions for correct loading Explain and agree surgical procedures and expected prosthetic solution with the patient, provide written treatment plan and further discuss with patient to ensure they understand all aspects of treatment. Management of expectations is crucial for the satisfaction of the patient with the final outcome of the treatment. Radiological investigations Radiographic imaging prior to implant placement is mandatory and the availability of reduced-dose cross-sectional imaging in limited volumes using Cone-Beam Computed Tomography (CBCT) has become widespread (see Chapter 8). Such imaging can be useful in many cases and may provide information not available with plain radiography – such as bone width and detailed topography of specific anatomic locations, e.g. sinus. However, practitioners should always use appropriate case-based imaging observing the principles of ‘As Low As Reasonably Practicable’ (ALARP)(see Chapter 8). • • • • Plain radiography should normally be the first-line radiological investigation as it has the lowest dose and in some straightforward cases may be adequate for implant placement surgery. However, radiographic imaging for dental implant surgery with plain radio­ graphy should normally be performed with a radiographic tem­ plate and/or radiomarker to assess magnification and distortion and allow accurate measurements of bone height – for example over the inferior alveolar nerve. CBCT should not automatically be used as an imaging technique as the dose is higher, but should be considered for cases of reduced bone width/height, reduced space between teeth, proximity to anatomic locations (mental nerve, sinus, etc.) Radiographic imaging for dental implant surgery with 3D tech­ niques should normally be performed with a radiographic tem­ plate to indicate the relationship between the available bone volume, the relative position of important anatomical structures, and the intended prosthesis position. Radiographic templates may consist of: • The existing denture with radio-opaque markings added (e.g. gutta percha) • A diagnostic wax-up employing radio-opaque teeth http://dentalebooks.com 276 • C L I N I C A L D E N T I S T RY • • A vacuum-formed template to fit over the natural teeth with radio-opaque composite in the positions of the proposed replacement teeth • Holes in the radio-opaque material simulating screw-access holes can be helpful • It is also useful to highlight the mucosal fit surface of the intended prosthesis to show soft tissue thickness • Non-metallic markers are necessary when 3D imaging is to be performed 3D imaging can be combined with proprietary software pro­ grammes to aid treatment planning; CAD-CAM (Computer Aided Design-Computer Aided Manufacture) techniques can also be used to produce surgical templates to assist in implant placement, although improved accuracy is not always guaranteed. Prosthesis design Although there is often considerable variation in the components of different implant systems, the prosthetic phase of implant treatment is essentially similar to conventional prosthodontics. Special impres­ sion copings are used and this sometimes requires different impres­ sion tray designs. Figure 12.2A and B show typical mechanical components of an osseointegrated implant; tissue level and bone level. The prosthesis is normally attached to an implant via a secondary transmucosal component known as an abutment. Abutments vary in design and material: • • • • • • An implant with a separate abutment (two-piece system) An implant with an integral abutment (one-piece system) Overdenture retaining abutments (individual, or splinted with a bar) (Figure 12.3) Abutments onto which a fixed prosthesis can be cemented, or screw-retained (Figure 12.4) Titanium, gold, or zirconia abutments Retaining screws may be made from titanium or gold. Removable implant-retained prostheses • • • Implants cannot convert a poor denture into a successful denture Implants can, however, provide critical retention that will greatly assist in the stability of a denture and may reduce the require­ ment for clasps Implants may be particularly useful in patients requiring remov­ able appliances who: • Have severely atrophic alveolar ridges • Are poor denture wearers http://dentalebooks.com I m p lant o l o g y Crown Occlusal screw Abutment Soft tissue Smooth transmucosal implant shoulder Bone Microtextured implant body • 277 A Crown Abutment Soft tissue Bone Microtextured implant body B Figure 12.2 A ‘Soft tissue level’ implant screw-retained single crown. B ‘Bone level’ implant single crown. © Institut Straumann AG, 2011. All rights reserved. By courtesy of Institut Straumann AG. Figure 12.3 A bar-retained lower overdenture using osseointegrated implants. © Institut Straumann AG, 2011. All rights reserved. By courtesy of Institut Straumann AG. http://dentalebooks.com 278 • C L I N I C A L D E N T I S T RY Figure 12.4 Some fixed prosthetic solutions using osseointegrated implants. © Institut Straumann AG, 2011. All rights reserved. By courtesy of Institut Straumann AG. • • • • • • • Have xerostomia (perhaps related to medication or rheuma­ toid conditions) • Have oral mucosal conditions, including blistering diseases All removable prostheses must be designed and fabricated accord­ ing to the recognized principles described in Chapter 18 on remov­ able prosthodontics Overdenture retention can be provided with special dentureretaining abutments (ball-anchors or press-stud attachments), or by means of a bar linking adjacent implants Clips or sockets are then included in the denture Careful denture design is required in order to accommodate the retentive elements without encroaching on tongue space or lip support Significant improvements in Oral Health Related Quality Of Life (OHRQoL) outcomes have been reported with the use of implantretained complete lower overdentures ‘Combination syndrome’ can occur when a conventional upper complete denture is opposed by an implant-retained complete lower denture, just as it can when the lower anteriors are natural teeth. Fixed implant-retained prostheses • • • Fixed crown and bridgework may be retained on the abutment by means of screw or cement retention Fixed prostheses may require greater attention to implant posi­ tioning relative to the intended tooth position for function, occlu­ sion, phonetics, and aesthetics (restoration-driven approach) Prosthetic planning should dictate the appropriate implant body size and design, and appropriate restorative platform for the intended prosthesis (rrestoration-driven approach) http://dentalebooks.com I m p lant o l o g y • • • • • 279 The prosthesis should be designed according to a pre-planned occlusal scheme Fixed implant restorations are frequently associated with high patient expectations, particularly in terms of aesthetics Prosthesis design should include the avoidance of inaccessible stagnation areas and allow adequate access for: • Home performed cleaning by the patient • On-going assessment of peri-implant health parameters Linking of teeth and implants is not generally recommended due to complications such as: • Intrusion of the natural tooth • Loss of cementation on the tooth abutment and resulting caries • Increased technical complications. Surgical aspects The placement of a dental implant is a surgical procedure and should be approached with the same considerations as every surgical procedure in terms of patient suitability and medical/dental fitness, surgical planning, and a continual process of on-going informed consent. It is often observed that an influential factor in the success of a surgical procedure is the experience of the operator. Appropriate surgical training and experience is therefore mandatory. Figures 12.5, 12.6, 12.7, and 12.8 show clinical images. Implant placement should only be performed following comprehen­ sive patient and site assessment with thorough pre-operative plan­ ning and subsequent to adequate periodontal/dental disease control. Figure 12.5 Implant placement. http://dentalebooks.com 280 • C L I N I C A L D E N T I S T RY Figure 12.6 Healing caps. Figure 12.7 Abutments. Figure 12.8 Implant-retained bridge. • • • Two-piece implant systems may be placed in either a transmu­ cosal or submucosal approach One-piece implant systems are often placed in a transmucosal approach Implants placed in a submucosal (submerged) approach require second-stage surgery to expose the implant and place a http://dentalebooks.com I m p lant o l o g y • 281 transmucosal healing cap, of which there can be different types depending on the requirements of each individual site. Surgical planning Successful implant osseointegration is dependent on several co-related factors; the surgical plan follows the restorative plan and should include many considerations. Patient-specific factors • • • • • • • Medical factors that may affect the patient’s suitability for surgery such as cardiac, lung, liver and kidney disease Medical factors that may influence healing such as diabetes, immunosuppression or corticosteroid therapy Environmental/Social factors such as smoking or alcohol abuse Dental factors such as a presence of or previous treatment for periodontal disease and relevant level of oral hygiene Psychosocial factors such as mental health conditions Age – passive eruption in young patients, cognitive decline and frailty in older patients Dental and periodontal health is a prerequisite, with control of existing disease being established prior to implant placement. Site-specific factors Following tooth extraction, the alveolar ridge resorbs in an apicolingual direction. The centre of the residual alveolar ridge becomes progressively removed from the original tooth position. Implant site planning has to take this factor into account; allowing the location of the bone to dictate the position of the implant may result in an inability to fabricate a prosthesis according to the principles detailed above. Implant site planning must consider: • • • • • • • Adequate access for necessary instrumentation Avoidance of adjacent anatomical structures such as adjacent teeth, nerves, or inappropriate perforation of cortical plates Absence of pathology Implants should emerge (when possible) through attached (kerat­ inized) mucosa Where adjacent teeth are present, the gap width for implant placement should allow for a minimum of 1.5 mm between implant and tooth Where adjacent implants are to be placed, the minimum distance between implants should be 3 mm The available bone volume and density to allow for correct threedimensional implant placement as dictated by the prosthesis • Ridge width should allow for a 1 mm bone wall on all aspects of the implant http://dentalebooks.com 282 • C L I N I C A L D E N T I S T RY • • • Ridge height should allow for adequate clearance over vital structures (e.g. IAN) • Ridge trajectory should allow for correct implant angulation, also considering whether the prosthesis is to be screw- or cement-retained • Where any of the above cannot be satisfied, bone augmenta­ tion may be required Bone augmentation may be achieved with: • Guided bone regeneration (GBR) – the simultaneous aug­ mentation of minor defects in bone thickness at the time of implant placement by using a resorbable or non-resorbable barrier membrane often in combination with bone grafts or substitutes • Onlay bone grafting – using block grafts, preferably in combi­ nation with GBR to increase the ridge width prior to the place­ ment of implants • Sinus lift – the placement of graft material into a carefully prepared space between the maxillary sinus lining and maxilla (sub-antral augmentation) Soft tissue augmentation may be required in order to ensure an adequate volume of attached mucosa at the intended implant site. Different periodontal muco-gingival surgical procedures are used for this to be achieved. The interaction between restorative and surgical planning is used to produce a surgical template, which is used during the implant osteotomy preparation to ensure accurate implant placement in the correct three-dimensional position with adequate surrounding bone and soft tissue. A good surgical template should be: • • • Of accurate fit and good stability so as not to interfere with drilling Made from clear plastic to allow visibility of drill markings Or, made with a guide tube in the case of CAD-CAM templates for guided surgery. Implant placement surgery • • • Pain and anxiety control must be adequate, bearing in mind the nature and duration of the procedure The duration of surgery will depend on operator ability and patient compliance; it should not exceed the likely duration of a safe volume of local anaesthetic Appropriate flap design is essential for good visibility and access, with adequate vascularity and mobility for tension-free closure of the soft tissues http://dentalebooks.com I m p lant o l o g y • • • • • 283 Flap design must also consider the management of the available attached mucosa Atraumatic flap elevation and retraction is important Atraumatic bone preparation is necessary with sharp rotary instruments and adequate cooling to avoid thermal injury to the bone. Piezosurgery (ultrasound) may also be employed. Precise drilling of the osteotomy is required to ensure adequate implant stability and avoid micromotion during the healing phase. Surgical complications Dentists who undertake implant surgery should be appropriately trained and competent to deal with complications related to surgical procedures associated with dental implants. Surgical complications may include: • • • • • • • • • • Pain (intra- or postoperative); some can be anticipated Swelling (oedema, seroma, haematoma); some can be anticipated Haemorrhage (primary, secondary, reactionary) Infection Bony fracture (e.g. atrophic mandible, cortical plate) Inappropriate implant positioning Implant osseointegration failure Bone graft failure Wound dehiscence or soft tissue loss Neurological disturbance (e.g. inferior alveolar nerve [IAN] or mental nerve involvement). Certain complications may have lifelong consequences for the patient. For example, damage to the inferior alveolar nerve may result in not only loss of sensation but potential irreversible neuropathic pain. If during the surgical procedure, it is suspected that the nerve has been damaged, the implant should not be placed; if the symptoms arise subsequent to implant placement then the implant should be removed within few hours of placement and referral to an appropriate specialist must be made as a matter of urgency. Interim restoration A temporary (interim) restoration is often used during the healing phases of implant surgery, following extraction, grafting, or implant http://dentalebooks.com 284 • C L I N I C A L D E N T I S T RY placement, particularly in visible sites where aesthetic considerations prevail. Interim restorations may include: • • • • • Acrylic removable partial dentures Fixed interim bridges (where the adjacent teeth require or are already crowned) Adhesive bridges Vacuum-formed retainers with prosthetic teeth The placement of temporary mini implants adjacent to the defini­ tive implant. Important considerations include: • • • • • Avoidance of soft tissue compression at the surgical site in the immediate postoperative period to avoid a wound dehiscence Avoidance of implant micromotion in the immediate postopera­ tive period to avoid failure of osseointegration The ability for the interim to be easily removed and replaced for each surgical phase The ability for modification of the shape of the interim appliance given the changes in local site morphology that will occur The condition of any existing dentures and their suitability for use as interim appliance. Maintenance The maintenance of osseointegration is essential for the long-term survival of the implant. However, implant survival in the oral cavity is not the same as implant success, as an implant may remain inte­ grated but diseased for some time before ultimately failing. Implant success includes: • • • • • Absence of subjective complaints such as pain or discomfort Maintenance of healthy peri-implant soft tissues Absence of on-going peri-implant bone loss after the placement of prosthesis Absence of mobility The possibility of completing the planned restoration. Technical complications A collective term for mechanical damage or failure of of the implant/implant components and supra-structures. • • • Loss of screw hole seal Loss of cement Loss of retention http://dentalebooks.com I m p lant o l o g y • • • • • • • • 285 Abutment loosening/fracture Screw loosening or fracture Fixed prosthesis misfit Damage to veneering material Wear or loss of retaining components Damage to/loss of prosthesis Implant fracture. It should be noted that implant-retained overdentures often require frequent replacement of retaining devices or of the denture itself due to more rapid wear as a consequence of improved function. Biological complications Peri-implant diseases • Peri-implant mucositis: ‘a reversible inflammatory process in the soft tissues surrounding a functioning implant’. Recent systematic reviews reported a high prevalence of peri-implant mucositis in patients previously treated for periodontal disease (up to 79% of the subjects/patients and a range of 50–>90% for the implant-based analysis). • Peri-implantitis: ‘an inflammatory process, which in addition to the symptoms of the soft tissues presents also with bone loss around the implant’. Recent systematic reviews reported that the prevalence of peri-implantitis at 5–10 years after implant place­ ment is in the range of 10% for the implant-based analysis and 20% for the subject-/patient-based analysis. However, the indi­ vidual reported figures in different studies are variable and not always easily comparable. Nevertheless, higher values have been reported in another systematic review evaluating patients previ­ ously treated for periodontal disease. • Treatment: The treatment of peri-implantitis is challenging and not predictable. Whilst non-surgical therapy (with the use of titanium instruments/scalers) results in the control of periimplant mucositis, it is not sufficient for the treatment of periimplantitis where in a large number of cases the disease will progress even after surgical procedures, which according to the extent of the disease and bone defect morphology can be either a regenerative (GBR) or an open flap/resective approach. In severe cases, explantation of the implant should also be considered. • Risk factors: A number of risk factors for peri-implantitis have been reported. Amongst them, the highest volume of scientific evidence is associated with poor oral hygiene, previ­ ous presence of periodontal disease (treated), lack of appropri­ ate supportive (periodontal) therapy and smoking. Other factors that have been suggested but where the relevant http://dentalebooks.com 286 • • C L I N I C A L D E N T I S T RY evidence is still weak are: diabetes, alcohol consumption, genetic traits and implant surface. In order to reduce the risk related to oral hygiene, the dentist must ensure that the suprastructure supported by the implants facilitates the proper access for oral hygiene procedures. Maintenance/supportive therapy: The dentist should en­­sure that all patients receive an individualized maintenance/ supportive (periodontal) therapy program that is effective in the prevention of the development or recurrence of infection around teeth and implants. Whilst there is no specific perio­ dontal supportive therapy regime for dental implants, the dentist should apply similar principles to those recommended for periodontitis patients. These should include provision of appropriate information and instruction on the use of selfperformed plaque control with emphasis in the use of inter­ proximal brushes. Furthermore, and according to the patient’s risk assessment profile, the patient should be enrolled in an individually designed maintenance/supportive therapy pro­ gramme (3/6/12 months according to needs/risk profile), which includes oral hygiene control and subgingival/mucosal debridement. The presence of high bleeding scores and an increased pocket depth of ≥5mm renders further radiographi­ cal examination and treatment of the site necessary. Implant loss or removal • Early implant loss: The dental implants are lost prior to loading, expressing an inability of the host to establish osseointegration. • Late implant loss: The dental implants are lost after loading, expressing an inability of host to maintain osseointegration after a period of function and most often is the result of development of peri-implantitis. Current developments in implant treatment Immediate placement of implants into extraction sockets • • • Placement of implants into extraction sockets is now more com­ monplace. Claimed advantages are less traumatic surgery, main­ tenance of the bone volume in the site and reduced treatment time However, implant placement in the line of the root is not advanta­ geous as it can result in a lack of buccal bone wall thickness and unsightly soft tissue recession The natural loss of labial plate following extraction is not pre­ vented by implant placement and there is a higher risk of aes­ thetic complications http://dentalebooks.com I m p lant o l o g y • • 287 Placing the implant deeper into the extraction socket may increase the risk of progressive biological complications at a later date. Immediate loading of implants • • • • • This may be considered as a potential treatment option where bone conditions and occlusal factors are favourable and there is good primary implant stability The protocol can be considered to be clinically and scientifically validated for use with splinted implants in the mandible There is less sound evidence for the use of immediate loading in the maxilla where bone volume and density are reduced The cortical threshold for micromotion beyond which implants may fail to integrate is neither known nor controllable The use of techniques such as periotest values or resonance fre­ quency analysis to determine initial implant stability has some support in the literature. Short or narrow implants • • • There is evidence to show similar survival rates between shorter and normal length implants placed under similar conditions Reduced diameter implants also show similar survival rates and may be useful in small jaws, in narrow gaps, and in certain nonaesthetic conditions to avoid the need for bone augmentation The selection of the appropriate implant size is based on many factors, but must be primarily led by appropriate prosthetic design/restoration needs and loading considerations. Flapless implant surgery • • • • It has been suggested that the placement of implants without elevation of a mucoperiosteal flap may in some circumstances be useful in reducing surgical morbidity Flapless implant placement does not allow visualization of the morphology of the underlying ridge Consequently, flapless implant placement may only be performed with a computer designed guided surgery template Considerable operator experience is also necessary as the risk of surgical errors is high; to date, errors in implant positioning are still reported using guided surgery templates. CAD-CAM framework manufacture and design • The use of intra-oral optical scanning devices and computeraided design and manufacture has progressed rapidly and highly developed workflows now permit very accurate milling or 3D http://dentalebooks.com 288 • • C L I N I C A L D E N T I S T RY printing of prosthetic substructures from titanium and other materials All-ceramic crown and bridgework can also be fabricated to a high level of accuracy with such techniques. Full-arch immediate tooth replacement • • The placement of two short anterior implants and two long, angulated posterior implants with the provision of an immediate fixed prosthesis has raised interesting debate in the field of implant dentistry However, the careful review of the available literature especially in terms of long-term data and biological complications as well as the standard principles of good clinical practice in implant treat­ ment must still apply: • Teeth that are suitable for restoration by conventional means should be retained • The removal of teeth affected by periodontal disease does not remove the susceptibility of the patient to peri-implant disease • Such prostheses have to be designed so that the patient can adequately clean the implant sites • This may be precluded by poor prosthetic design or where large, pink ‘flanges’ or prosthetic ‘gum-work’ is required to provide acceptable aesthetics, lip support, and prevent pho­ netic problems due to air-escape • In such circumstances, the risk of peri-implant disease may be increased due to difficulty in self-performing oral hygiene procedures • The technical complication rate in such prostheses, especially when large cantilevers are employed, needs to be reviewed. References FDGP (UK) Training Standards in Implant Dentistry 2012. http://dentalebooks.com Oral medicine Oral infections 289 Recurrent oral ulceration 298 Vesiculobullous lesions 301 White patches 305 Potentially malignant lesions and conditions 307 Pigmented lesions of the oral mucosa 310 Mouth cancer 312 Miscellaneous lesions 314 Salivary gland disorders 315 13 Effects of drugs on the teeth, oral mucosa and salivary glands 321 Disorders of the temporomandibular joint 321 Facial pain 323 Oral manifestations of systemic disease 327 HIV infection and acquired immune deficiency syndrome (AIDS) 333 Halitosis (oral malodour) 336 This chapter covers oral medicine but there are also two laboratory specialties with overlapping interests (oral microbiology and oral pathology). Oral medicine Concerned with the oral health care of patients with chronic recurrent and medically related disorders of the mouth and with their diagnosis and nonsurgical management. Oral medicine is the specialty of dentistry that sits at the interface between dentistry and medicine. Many oral medicine specialists have dental and medical qualifications. This reflects that the specialty had its origins in dentistry, but has evolved to formally encompass medical aspects of care. A medical qualification is no longer an essential requirement in the UK. Oral microbiology Diagnosis and assessment of facial infection – typically bacterial and fungal disease. This is a clinical specialty undertaken by laboratory-based staff, who provide reports and advice based on interpretation of microbiological samples. Oral and maxillofacial pathology Diagnosis and assessment made from tissue changes characteristic of disease of the oral cavity, jaws and salivary glands. This is a clinical specialty undertaken by laboratory-based personnel. It includes the scientific study of the causes and effects of disease in the oral and maxillo-facial complex, an understanding of which is essential for diagnosis and for the development of appropriate treatments and preventative programmes. Oral infections Infections are more common in resource poor cultures than the Western world. http://dentalebooks.com 290 • C L I N I C A L D E N T I S T RY Bacterial infections A wide variety of bacterial infections may have oral lesions, although with the exception of dental caries and odontogenic infections (Chapter 3) and periodontal disease (Chapter 17) including Acute Necrotizing Ulcerative Gingivitis (ANUG), they are all relatively uncommon. Tuberculosis Oral involvement with Mycobacterium tuberculosis is infrequent though one third of the world population is infected – and is usually secondary to open pulmonary tuberculosis. Primary infections of the oral mucosa are rare, although recently incidence has increased, mainly amongst human immunodeficiency virus (HIV)-seropositive patients, and then often drug-resistant. Clinical features. Most commonly a persistent ulcer with indurated margins on the dorsal surface of the tongue, although other sites may be affected. Pain is a variable feature. Investigations and diagnosis. Biopsy, submitting the specimen for routine histopathology, DNA studies (PCR) and culture on an appropriate medium (e.g. Lowenstein–Jensen medium). Histopathological examination demonstrates the presence of caseating granulomata. Ziehl–Neelsen stain may reveal small numbers of acid- and alcoholfast mycobacteria. Treatment. Oral lesions respond to treatment of underlying pulmonary tuberculosis. Occasionally, infection with atypical mycobacteria is reported – most likely as a lymphadenitis in childhood. Increasing incidence of atypical mycobacterial infection (e.g. Mycobacterium aviumintracellulare) seen among immunocompromised patient groups. Gonorrhoea Sexually shared disease caused by Neisseria gonorrhoeae. Oral lesions occur as a result of orogenital contact with an infected partner. Particularly common amongst men who have sex with men (MSM). Affected patients may complain of a dry, burning sensation with associated altered taste sensation and halitosis. Clinical features. Presentation is variable. May include pyrexia, diffuse mucosal erythema involving the mouth and oropharynx, oral ulceration and grey/yellow pseudomembranes – readily removed to reveal a bleeding surface. Cervical lymphadenopathy may also be a prominent feature. Investigation and diagnosis. Swabs from suspected oral lesions submitted for culture. http://dentalebooks.com O ral m edicine • 291 Treatment. Azithromycin ± ceftriaxone. Syphilis Systemic sexually shared infection caused by the spirochaete Treponema pallidum. Incubation period 10–90 days. Infection may be acquired or congenital. Acquired syphilis divided into three stages: primary, secondary and tertiary. Incidence of syphilis is rising especially in MSM. Oral lesions are relatively uncommon. Clinical features Primary syphilis. Characterized by a painless round or ovoid ulcerated lesion (chancre), which develops at the site of entry. Lips are the most common site for extragenital lesions. Painless, rubbery cervical lymph­adenopathy may be a feature. Treponema pallidum is readily recovered from the chancre and therefore the lesion is highly contagious. The chancre resolves within 2–3 months. Secondary syphilis. Develops 1–4 months after healing of the primary chancre. Characterized by a generalized macular skin rash. Oral lesions, classically superficial ulcers or mucous patches, are highly contagious. May coalesce to form serpiginous lesions, ‘snail track ulcers’. Resolves within 2–6 weeks. Disease may then enter a latent phase which can become active as the tertiary stage of the disease. Alternatively the latent phase may last a lifetime. Tertiary syphilis. Uncommon in the Western world. Most distinctive lesion is the gumma – a chronic granulomatous reaction with central necrosis. In the mouth it presents in the midline of the hard palate, and perforation into the nasal cavity may ensue. Of low infectivity. Atrophic glossitis may also occur in this stage. Congenital syphilis. Lesions include tooth malformations (Hutchinson’s incisors and mulberry molars) caused by infection of the developing tooth germs; saddle deformity of the nose; frontal bossing. Investigation and diagnosis. Dark ground microscopy of exudate from primary chancre or secondary mucous patches. This is of limited value for oral lesions as other spirochaetes are commensals in the mouth. Definitive diagnosis is by serological tests: Treponema pallidum Haemagglutination Assay (TPHA) and Fluorescent Treponemal Antibody (FTA) test. Treatment. High-dose penicillin or doxycycline or erythromycin. Fungal infections The oral mucosa may be affected by a variety of fungal diseases, including: • • candidosis histoplasmosis http://dentalebooks.com 292 • • • C L I N I C A L D E N T I S T RY cryptococcosis paracoccidioidomycosis. With the exception of candidosis, all are uncommon in the UK. This section will concentrate on candidal infections which is the most common oral fungal infection. Candidosis (candidiasis) This is by far the most common oral fungal infection. Candida species can be isolated from the mouths of up to 70% of the normal population, where it exists as a commensal organism. C. albicans remains the most frequently isolated species. Non-albicans species now account for an increasing proportion of clinical issolates. Nonalbicans species of particular clinical importance include C. tropicalis, C. glabrata, C. parapsilosis, C. guilliermondii, C. krusei, C. pseudotropicalis and C. dubliniensis. A variety of local and systemic factors predispose to the development of candidal overgrowth and overt clinical infection (Table 13.1). Classification of oral candidosis – see Table 13.2. Clinical features Pseudomembranous. White/yellow plaques on the oral mucosa. These can be removed to reveal an erythematous base which may bleed. Erythematous. Erythematous areas on the oral mucosa (Figure 13.1). Most commonly affects dorsal surface of the tongue, palate, buccal mucosa. TABLE 13.1 Local and systemic factors predisposing to candidal infection Local factors Trauma Denture wearing Poor denture hygiene Xerostomia • • • • Systemic factors • Radiotherapy therapy • Antibiotic therapy • Corticosteroid of life – infancy and old age • Extremes mellitus • Diabetes deficiency (iron, folate and vitamin B ) • Nutritional • Immunosuppression smoking • Cigarette • High carbohydrate diet 12 http://dentalebooks.com O ral m edicine • 293 TABLE 13.2 Classification of oral candidosis Primary oral candidoses Acute Pseudomembranous Erythematous Chronic Pseudomembranous Erythematous Hyperplastic Candida-associated lesions Denture-induced stomatitis Angular cheilitis* Median rhomboid glossitis Secondary oral candidoses This term encompasses a complex and rare group of conditions in which superficial chronic mucocutaneous candidosis occurs in conjunction with endocrine abnormalities (hypoparathyroidism, hypothyroidism, hypoadrenocorticism (Addison’s disease) and diabetes mellitus) or immunodeficiency *Staphylococci and streptococci may also be involved in the aetiology of some cases of angular cheilitis. Figure 13.1 Erythematous candidosis. Denture-related stomatitis. Chronic erythema and oedema of the mucosa in contact with the fitting surface of the upper denture. Bacteria may also be implicated. Often coexists with angular cheilitis. Three subtypes have been described (Newton’s classification): I – pinpoint hyperaemia (some have suggested that this is simply a response to chronic trauma); II – diffuse erythema; III – granular (papillary hyperplasia). Angular cheilitis. Soreness, erythema and fissuring at the angles of the lips (Figure 13.2). Median rhomboid glossitis. Elliptical or rhomboid area of papillary atrophy centrally placed, anterior to the circumvallate papillae. Less commonly, it may have a hyperplastic or lobulated appearance. Chronic hyperplastic. Chronic, discrete adherent white plaque-like lesions (Figure 13.3). Most commonly occur at the commissures. May also affect other parts of the oral mucosa. http://dentalebooks.com 294 • C L I N I C A L D E N T I S T RY Figure 13.2 Angular stomatitis (cheilitis). Figure 13.3 Candidal leukoplakia. TABLE 13.3 Investigations in candidal infections Swab Smear Biopsy Pseudomembranous + + − Acute erythematous + + − Chronic erythematous + + − Chronic hyperplastic − − + Denture-induced stomatitis* + + − Angular cheilitis + + − Median rhomboid glossitis + + + *Swab and smear from palate and fitting surface of denture. Investigation and diagnosis. Essentially clinical although confirmation can be obtained with the investigations shown in Table 13.3. Screen for deficiencies, especially nutritional, and diabetes – FBC, ferritin, folate, vitamin B12 and glucose. Treatment. Eliminate predisposing factors if possible, e.g. reduce refined carbohydrate intake. Appropriate denture hygiene, store dentures in hypochlorite solution overnight. Antifungal agents. Topical: nystatin, amphotericin, miconazole; systemic: fluconazole, itraconazole. Azole antifungal agents should be http://dentalebooks.com O ral m edicine • 295 avoided in patients taking warfarin or lipid-regulating drugs, such as statins, due to clinically significant drug interactions. Viral infections A wide range of viruses are responsible for causing oral lesions. These include: herpes simplex virus (HSV) types 1 and 2; herpes zoster (VZV); Epstein–Barr virus (EBV, see hairy leukoplakia); Coxsackie and other enteroviruses; paramyxoviruses; human papillomaviruses (HPV). Primary herpetic gingivostomatitis Caused commonly by herpes simplex type 1. Type 2, which is more commonly associated with genital herpes, accounts for a proportion of cases. Transmission is via direct contact with recurrent skin lesions or infected saliva. In infancy and childhood, the disease may be subclinical and is self-limiting. May be attributed to teething. In adulthood the infection is usually more severe and may be sexually shared. Clinical features. Initial pyrexia, malaise, painful mouth and throat, associated cervical lymphadenopathy. Subsequent development of widespread intraoral vesicular lesions which rapidly rupture to form small irregular superficial ulcers with erythematous haloes. If the gingivae are affected they appear inflamed and bleed readily. Lesions are entirely self-limiting and resolve within 10–14 days. Investigation and diagnosis. Primarily based on history and clinical features. Can be confirmed by: polymerase chain reaction (detection of HSV DNA); detecting virus in a smear; viral culture; demonstration of a fourfold rise in antibody titre is a largely historical investigation. Treatment Mild cases. Treat conservatively with symptomatic measures such as oral fluids, prevention of secondary infection and analgesics. Moderate and severe cases or infections occurring in immunosuppressed patients. Systemic antiviral drugs (aciclovir or famciclovir) are useful, particularly if started early in the course of the disease. Recurrent herpetic infection Approximately 30% of patients subsequently develop recurrent infections, most commonly in the form of herpes labialis (cold sores). The virus lies dormant in the trigeminal ganglion and is reactivated by a variety of precipitating factors including: fever, trauma, exposure to sunlight, stress, menstruation and immunosuppression. Lesions affect the mucocutaneous junction of the lip or involve the nostril. Recurrence is heralded by a prodromal burning or prickling http://dentalebooks.com 296 • C L I N I C A L D E N T I S T RY sensation in the area followed by the formation of small vesicles which enlarge, coalesce and then rupture. Lesions then crust over and heal spontaneously. Less commonly recurrence can manifest intraorally as clusters of small superficial ulcers usually affecting the hard palate. Treatment. Lesions of herpes labialis can be treated with topical penciclovir 1% or aciclovir 5% cream applied every 2 hours during the prodromal stage. Chickenpox Primary infection with varicella zoster virus (VZV). Highly contagious; spread by droplets. Incubation period 14–21 days. Clinical features. Often a subclinical infection occurring primarily in children. Fever, malaise, anorexia, skin eruption affecting the face and trunk, cervical lymphadenitis. Skin lesions initially present as papules which evolve into vesicles, pustules and scabs. Commonly occur as crops – lesions are seen at varying stages of evolution. Oral lesions are characterized by small ulcers – may predate the appearance of the skin rash. Investigation and diagnosis. Diagnosis is largely clinical. Rising antibody titre may confirm clinical suspicion. Treatment. Symptomatic as disease is self-limiting. In immunosuppressed patients systemic antiviral agents (aciclovir, famciclovir or valaciclovir) may be given. Shingles Localized reactivation of herpes zoster in sensory ganglion leading to vesicular eruption affecting the skin dermatome supplied by that nerve. Most cases affect the elderly or immunosuppressed. Clinical features. Typically involves thoracic dermatomes, with only about 30% involving divisions of the trigeminal nerve – usually mandibular division. Localized pain, often described as a burning sensation and/or altered sensation in the distribution of the nerve, commonly precedes the appearance of the skin eruption. Skin lesions are initially erythematous – subsequently develop vesicles which form scabs after a few days. Unilateral oral ulceration when mandibular or maxillary divisions of the trigeminal nerve involved. If ophthalmic division affected an urgent ophthalmological opinion should be arranged due to the risk of corneal ulceration and subsequent blindness. Investigation and diagnosis. Primarily a clinical diagnosis. Confirmed by isolation of VSV in vesicular lesions or testing for specific immunoglobulin M (IgM) to VZV. http://dentalebooks.com O ral m edicine • 297 Treatment. Systemic high-dose aciclovir (800 mg five times daily for 7 days); less effective once the vesicular rash appears. Aciclovir and systemic corticosteroids may be helpful in reducing incidence of postherpetic neuralgia. Herpangina Relatively common infection caused by various Coxsackie viruses (A7, 9, 16; B1–5). Occurs most commonly in children – may be mistaken for teething. Characterized by pyrexia, dysphagia, sore throat and multiple small vesicles on the soft palate and uvula which rupture to leave superficial ulcers. Treatment. No specific treatment. Management aimed at controlling symptoms (soft diet, fluids, prevention of secondary infection and analgesics). Hand, foot and mouth disease Common viral infection predominantly affecting young children. Occurs in small epidemics. Caused by various Coxsackie viruses, particularly A16 (less commonly A5 or 10). May be subclinical infection. Characterized by low-grade pyrexia, malaise, anorexia, multiple shallow ulcers of the labial and buccal mucosa often indistinguishable from primary herpetic gingivostomatitis although no gingival involvement; papular or vesicular rash on the palms and soles. Management as for herpangina. Human papillomaviruses (HPV) The human papillomaviruses are a group of more than 100 different types of virus. Several types are associated with specific oral lesions. Squamous cell papilloma. Common benign tumour found most frequently in patients in third to fifth decades. Most commonly presents on the soft palate although may also affect dorsum and lateral surfaces of tongue or the lower lip. Clinically presents as a pedunculated or sessile cauliflower-like swelling. HPV 6 or 11 found in up to 80% cases. Verruca vulgaris. Common skin lesion, particularly in children. Occasionally may affect oral mucosa. Usually appears as a firm, sessile, white, exophytic lesion on the lip and may be associated with autoinoculation from pre-existing skin lesion. Predominantly associated with HPV types 2 or 4. Condyloma acuminatum. Usually presents on anogenital mucosa, although may also present on oral mucosa. Present as multiple white or pink nodules which may coalesce to form soft sessile swellings. Associated with HPV types 6, 11 or 16. More common in HIVseropositive patients. http://dentalebooks.com 298 • C L I N I C A L D E N T I S T RY Multifocal epithelial hyperplasia (Heck’s disease). Rare benign lesion of oral mucosa characterized by multiple painless papules most commonly on the lower lip and may extend onto the vermillion border. More common in certain ethnic groups (e.g. Inuit and Indians from North and South America). Possible genetic predisposition. Associated with HPV type 13 or 32. Recurrent oral ulceration Oral ulceration Ulceration is defined as a break in the continuity of an epithelial lining. Causes are summarized in Table 13.4. Recurrent aphthous stomatitis Recurrent aphthous stomatitis (RAS) is a common oral condition of unknown aetiology affecting approximately 20% of the population (Figure 13.4). Three types are recognized, although it is unclear if they represent variants of the same disease or are distinct entities: minor, 80–85%; major, 10–15%; herpetiform, 5%. Clinical features. are shown in Table 13.5. Aetiological factors. Can be considered as host or environmental factors. Evidence for aetiological factors can be summarized as: TABLE 13.4 Causes of oral ulceration Traumatic Mechanical Chemical Thermal Radiation Artefactual Idiopathic Recurrent aphthous stomatitis including Behçet’s syndrome Infection Viral Bacterial Fungal Associated with systemic disease Haematological disorders Crohn’s disease Ulcerative colitis Associated with dermatological diseases Lichen planus Vesiculobullous disorders Neoplastic Squamous cell carcinoma and other tumours Drug-induced Cytotoxic agents Nicorandil http://dentalebooks.com O ral m edicine • 299 Figure 13.4 Aphthous ulceration. TABLE 13.5 Clinical features of minor, major and herpetiform oral ulceration Minor Major Sex ratio M=F M=F Herpetiform F>M Age of onset (years) 10–19 10–19 20–29 No. of ulcers <10 <5 10–100 Size of ulcers <10 mm >10 mm 1–2 mm Larger if ulcers coalesce Duration 4–14 days >30 days >30 days Recurrence rate 1–4 months <monthly <monthly Sites affected Labial and buccal mucosa, tongue Labial and buccal mucosa, tongue, palate, pharynx Labial and buccal mucosa, soft palate, floor of mouth Scarring Uncommon Common Possible if ulcers coalesce Genetic. Family history in up to 45% cases. High concordance rate among identical twins. Several HLA associations reported. Nutritional deficiencies. Haematological deficiencies (most commonly iron, although may also be associated with vitamin B12 and folic acid). Found in approximately 20–30% of patients with RAS. Some reports also suggest increased incidence of vitamin B1 and B6 deficiencies. Systemic diseases. Ulcers may occur in association with a variety of systemic disorders, e.g. coeliac disease, Crohn’s disease, ulcerative colitis and cyclic neutropenia. Endocrine. In a small proportion of female patients RAS may be more severe during the luteal phase of the menstrual cycle, related to the http://dentalebooks.com 300 • C L I N I C A L D E N T I S T RY increased levels of progestogens and decreased oestrogens. Remissions often occur during pregnancy. Stress/anxiety. Conflicting reports in the literature; this issue remains unresolved. Trauma. Minor trauma may initiate ulceration in susceptible patients. Influences the site of ulceration. Allergy. Some reports suggest associations between RAS and exposure to dietary allergens. Infection. Conflicting data on the role of oral streptococci as direct pathogens or antigenic stimuli for production of antibodies that cross-react with keratinocyte determinants. Similarly, some investigators have suggested a role for VZV and HSV although the results require confirmation. Smoking. Negative association between RAS and cigarette smoking. Onset of RAS in some patients may coincide with cessation of smoking. Investigation and diagnosis. Full blood count, assays of ferritin, vitamin B12 and folate to exclude nutritional deficiency. In areas where there is a high prevalence of coeliac disease, or if the patient has features suggestive of malabsorption, coeliac serology (antiendomysial antibody or tissue transglutaminase antibodies) is appropriate as a screen to exclude coeliac disease. No specific diagnostic tests. In patients who are rarely free of ulcers, allergy may be a contributing factor and patch testing can identify dietary and/or environmental allergens. Treatment. No specific management available for the majority of patients. Correct any haematinic deficiencies. In general, symptoms can be reduced although no treatment consistently prevents recurrences (Table 13.6). TABLE 13.6 Treatment options in recurrent oral ulceration Antiseptic mouthwashes Chlorhexidine 0.2% Benzydamine hydrochloride Antibiotics Tetracycline mouthwash Topical corticosteroids Hydrocortisone pellets Betamethasone mouthwash Beclometasone spray Systemic corticosteroids Prednisolone Other Azathioprine Dapsone Colchicine Thalidomide Biological agents http://dentalebooks.com O ral m edicine • 301 TABLE 13.7 Features of Behçet’s syndrome Oral Minor, major or herpetiform aphthae Ocular Uveitis, optic atrophy, retinal vasculitis Genital Ulceration Dermatological Pustules, erythema nodosum Neurological Symptoms resembling multiple sclerosis, pseudobulbar palsy Joint disease Recurrent arthralgia involving large joints Miscellaneous Thromboses, depression, renal disease, anorexia, colitis Behçet’s syndrome Comprises a triad of: recurrent aphthous stomatitis, genital ulceration and posterior uveitis. Cause unknown but it may have an autoimmune/autoinflammatory basis. Only about 42% of cases show the classic triad although >90% have oral ulceration. Diagnosis is usually made if two of these features are present. Any of the three variants of aphthous stomatitis may occur although there is an increased prevalence of herpetiform and major aphthae. Other manifestations, occurring with varying frequency, now recognized as components of the syndrome include: cutaneous lesions, neurological problems, joint lesions, intestinal lesions, haematological abnormalities and vascular lesions. Age of onset mainly third decade although children and older adults can develop the condition. Male preponderance (M: F, 2.3: 1). Disease is more severe in men. There is a significant geographic variation, with the syndrome being more common in the Eastern Mediterranean, China, Korea and Japan. Clinical features. are shown in Table 13.7. Investigations and diagnosis. No universally agreed diagnostic criteria. Diagnosis is essentially clinical. Exclude nutritional deficiency as a contributing factor. Strong association with HLA B51 may support the diagnosis. Treatment. Overall treatment with immunosuppressive agents, e.g. corticosteroids, azathioprine, colchicine, tacrolimus, thalidomide, or biological agents. Oral ulceration can be managed as for RAS. Ophthalmological opinion to exclude ocular involvement should be sought as this may lead to visual impairment or blindness. Vesiculobullous lesions Classified as intraepithelial or subepithelial (Table 13.8). Table 13.9 shows the immunopathological features of vesiculobullous disorders. http://dentalebooks.com 302 • C L I N I C A L D E N T I S T RY TABLE 13.8 Classification of vesiculobullous lesions Intraepithelial Subepithelial Pemphigus Viral infections Herpes simplex Herpes zoster Coxsackie Epidermolysis bullosa (simplex types) Angina bullosa haemorrhagica Mucous membrane pemphigoid Bullous pemphigoid Dermatitis herpetiformis Lichen planus Erythema multiforme Epidermolysis bullosa (gravis and dystrophic types) Linear IgA disease • • • TABLE 13.9 Immunopathological features of vesiculobullous disorders Disease Direct immunofluorescence Indirect immunofluorescence Pemphigus Intercellular IgG and C3 Titre correlates with disease severity Mucous membrane pemphigoid Linear IgG and C3 at basement membrane zone Essentially negative Bullous pemphigoid Linear IgG and C3 at basement membrane zone Positive in ~75% of cases Linear IgA disease Linear IgA and C3 at basement membrane zone Negative Dermatitis herpetiformis Granular deposits of IgA and C3 at tips of dermal papillae Negative Angina bullosa haemorrhagica (localized oral purpura) Clinical features. Predominantly affects older people. Characterized by the rapid formation of blood-filled blister, usually on soft palate although may occur on any other part of the oral mucosa. Blister ruptures to leave a superficial ulcer, which is entirely self-limiting. Unknown aetiology, no coagulation defect identified. Association with use of corticosteroid inhalers has been suggested. Investigation and diagnosis. Check clotting screen and full blood count to ensure normal haemostatic components. Rarely may require biopsy to differentiate from pemphigoid. http://dentalebooks.com O ral m edicine • 303 Treatment. Reassurance and use of an antiseptic mouthwash for symptomatic relief. Pemphigus Serious, rare autoimmune skin disease with several different variants: pemphigus vulgaris; pemphigus vegetans; pemphigus foliaceous; pemphigus erythematosus. The latter two variants rarely, if ever, have oral manifestations. Pemphigus vulgaris. The most common and most severe variant. Predominantly affects females. Presents in middle age. More common among those of Ashkenazi Jewish and Mediterranean descent. Clinical features. Characterized by widespread bullous lesions affecting mucous membranes and/or skin. Oral lesions occur in almost all patients and may be the presenting feature in up to 50%. In some cases oral lesions may be the only manifestation of the disease predating the development of skin lesions for a considerable time. Positive Nikolsky sign, although this is not pathognomonic of pemphigus. Intact intraoral bullae are rare. Tend to rupture shortly after they form to leave irregular areas of non-specific ulceration. Pain is often a prominent feature. Despite widespread involvement scarring is uncommon. Untreated, the disease may be fatal due to extensive skin involvement leading to fluid and electrolyte imbalance. Investigation and diagnosis. Routine histopathology of perilesional tissue together with direct and indirect immunofluorescence. IgG and C3 bind to component of desmosomes (predominantly desmoglein 3). Circulating antibody titre reflects severity of disease and can be used as a marker of disease activity. Treatment. Immunosuppressive therapy with systemic corticosteroids ± azathioprine or other immunomodulating drugs. Pemphigus vegetans. Considered to be a milder variant of pemphigus vulgaris. Characterized by the formation of hyperplastic vegetations of granulation tissue when bullae rupture. Oral lesions occur in approximately 50% of cases. Mucous membrane pemphigoid. Chronic subepithelial bullous disorder principally affecting the elderly. More common among females (F: M, 2: 1). Lesions can occur on oral and genital mucosa, conjunctiva and less commonly skin. Characteristically heals by scarring, particularly on the conjunctiva. Clinical features. Oral mucosa almost invariably involved while skin lesions are uncommon. Bullae are thick walled and therefore may remain intact for several days before rupturing to leave super­ ficial areas of ulceration. May also present as desquamative gin­ givitis. Ocular involvement is potentially serious and may lead to blindness. http://dentalebooks.com 304 • C L I N I C A L D E N T I S T RY Investigation and diagnosis. Histopathology demonstrates subepithelial bulla formation. Immunofluorescence – IgG and C3 at basement membrane. Treatment. Topical corticosteroids are generally effective for oral lesions. Systemic corticosteroids and/or dapsone in severe cases. Bullous pemphigoid. Primarily a bullous disorder of skin with oral lesions occurring in only one-third of patients. A disease of the elderly – most patients >60 years. Males and females equally affected. Skin lesions on limbs and trunk may begin as a non-specific urticarial rash several weeks before the appearance of vesiculobullous lesions. Clinically the oral lesions are indistinguishable from those of mucous membrane pemphigoid although they heal rapidly without scarring. Erythema multiforme Self-limiting acute vesiculobullous disease affecting skin and/or mucous membrane. Usually affects young adult males. Aetiology unknown in most cases, although recognized precipitating factors include: • infections – HSV, Mycoplasma pneumoniae • drugs – sulphonamides, barbiturates, thiazide diuretics, tetracyclines, carbamazepine • other – radiotherapy, malignancy, pregnancy. Clinical features. Wide spectrum of disease severity and presentation. May affect mouth, skin and other mucosal surfaces, alone or in any combination. Prodromal symptoms of upper respiratory tract infection followed by appearance of skin and/or mucosal lesions. Variety of skin lesions may occur, most commonly affecting hands and feet, including an erythematous maculopapular rash. Vesiculobullous lesions and classical ‘target’ or ‘iris’ lesions. Oral lesions are characterized by haemorrhagic crusting of the lips together with extensive bullous lesions which rapidly rupture to form widespread painful erosions. Ocular involvement may lead to conjunctival scarring and blindness. Symptoms usually subside within 2 weeks although recurrences may occur. Investigation and diagnosis. Diagnosis usually based on clinical picture but can be confirmed with biopsy. Treatment. Identify and eliminate precipitating factor if possible (e.g. aciclovir if episodes known to be triggered by herpes simplex infection). Prevent dehydration. Systemic corticosteroids (± azathioprine) in severe cases. Epidermolysis bullosa Complex group of syndromes with over 30 different types of varying severity. Inherited as autosomal dominant or recessive conditions. http://dentalebooks.com O ral m edicine • 305 Most severe forms become evident shortly after birth and are generally incompatible with life while milder forms may not become apparent until adolescence or adulthood. Characterized by fragility of skin, leading to formation of bullae in response to minor trauma. In severe forms bullae may arise spontaneously. Healing occurs with scarring. Systemic corticosteroids, phenytoin and vitamin E may be of benefit in some patients. Dermatitis herpetiformis Uncommon autoimmune-mediated blistering disease of skin that usually affects middle-aged males. Related to coeliac disease and gluten hypersensitivity. Most patients have no evidence of malabsorption although most have at least histological evidence of jejunal involvement. Skin lesions characterized by an intensely itchy papulovesicular rash on the trunk and limbs. Oral lesions range from asymptomatic erythematous areas to extensive erosive patches. Incidence of oral lesions may be up to 70%. Linear lgA disease Rare autoimmune subepidermal vesiculobullous disorder of skin which may be a variant of dermatitis herpetiformis. Gluten hypersensitivity may be a feature although this is less common than in patients with dermatitis herpetiformis. Triggered by drugs in some cases. Oral lesions include persistent non-specific ulceration. White patches Classification. (Table 13.10) White sponge naevus Benign keratin defect; autosomal dominant mode of inheritance with incomplete penetrance and variable expression. Clinical features. Diffuse, ill-defined, thickened white lesions most commonly affecting buccal mucosa. Less commonly labial mucosa, tongue and floor of mouth. A proportion of patients have similar lesions involving nasal, rectal or genital mucosa. Investigation and diagnosis. Biopsy will confirm diagnosis although clinical features are generally sufficient. Treatment. Reassurance. No specific treatment required. Darier’s disease (follicular keratosis) Rare condition transmitted by an autosomal dominant pattern of inheritance although many cases may arise as new mutations. Skin lesions initially appear as multiple small papules, particularly on the forehead, scalp and neck, which subsequently become grey/brown as http://dentalebooks.com 306 • C L I N I C A L D E N T I S T RY TABLE 13.10 Classification of white patches Genetic White sponge naevus Darier’s disease Dyskeratosis congenita Pachyonychia congenita Hereditary intraepithelial dyskeratosis Traumatic Chemical burn Mechanical (frictional) Thermal burn: smokers’ keratosis, nicotinic stomatitis Infection Candidosis (pseudomembranous and hyperplastic types) Hairy leukoplakia Syphilitic leukoplakia Idiopathic Leukoplakia Dermatological Lichen planus Lupus erythematosus Metabolic Associated with renal failure (uraemic stomatitis) Neoplastic Squamous cell carcinoma they ulcerate and crust over. Lesions become foul smelling when secondarily infected. Oral lesions occur in about 50% and appear as minute white papules which coalesce. Common sites include palate and gingivae. Pachyonychia congenita Uncommon disease inherited as an autosomal dominant condition. Characterized by dystrophic changes affecting the nails which are present at birth or develop shortly after; hyperhidrosis and palmoplantar keratosis in 40–60%. Oral lesions are usually present and consist of white, opaque thickening of the dorsum and lateral margins of the tongue. Involvement of the buccal and labial mucosa is less commonly seen. Dyskeratosis congenita Rare inherited condition (X-linked) characterized by hyperpigmentation of skin, dystrophy of the nails and oral leukoplakia. Oral lesions most commonly appear in early childhood and initially present as multiple vesicles/ulcers followed by the development of white plaques, which may later undergo malignant transformation. Chemical burns Various chemicals or drugs used in self-medication may produce burns if held in contact with the oral mucosa (e.g. aspirin and choline salicylate). Presents as an irregular white patch with oedema, http://dentalebooks.com O ral m edicine • 307 necrosis of the epithelium, sloughing and ulceration. The lesion resolves within several days following removal of the irritant. Frictional keratosis Localized white patch lesion that forms in response to chronic low-grade trauma from irritants such as cheek biting, sharp cusps or ill-fitting dentures. Lesion will resolve if source of irritation is removed. Smokers’ keratosis Regular use of tobacco often results in appearance of discrete white plaques on the oral mucosa, typically affecting buccal mucosa at the commissures, tongue or palate. Chemical irritation may also be involved in the aetiology of these lesions. Nicotinic stomatitis Seen frequently in heavy pipe smokers. Presents as diffuse grey/white thickened appearance affecting the posterior palate with numerous red papules, in the centre of which are the dilated orifices of swollen mucous glands. Regresses rapidly on cessation of smoking habit. Not considered to have any malignant potential. Renal failure Rarely, oral keratosis, predominantly affecting the floor of mouth and tongue, may be a feature of chronic renal failure. The white plaques regress on treatment of the renal disease. The following white patch lesions are discussed elsewhere: leukoplakia (p. 307), candidosis – pseudomembranous and hyperplastic types (p. 292/293), hairy leukoplakia (p. 335), lichen planus (p. 327), lupus erythematosus (p. 329), neoplasia (p. 312). Potentially malignant lesions and conditions A lesion can be regarded as potentially malignant if it is associated with a significantly increased risk of cancer. However, it must be stressed that most mouth cancers arise de novo with no recognizable preceding premalignant state. Potentially malignant lesions of the oral mucosa include: leukoplakia; erythroplakia; chronic hyperplastic candidosis; lichen planus (p. 327); oral submucous fibrosis; sideropenic dysphagia. Leukoplakia and erythroplakia Leukoplakia. is defined as a white patch or plaque on the oral mucosa that cannot be removed by scraping and cannot be http://dentalebooks.com 308 • C L I N I C A L D E N T I S T RY characterized clinically or pathologically as any other disease. The definition has no histological connotation. Thus the diagnosis is essentially one of exclusion. Erythroplakia. is defined as a bright red velvet plaque on the oral mucosa which cannot be characterized clinically or pathologically as being due to any other condition. While the term leukoplakia does not imply a particular type of behaviour, a small percentage of such lesions can be considered premalignant and a few may even be invasive tumours at initial presentation. Thus the lesion is highly significant. Unfortunately it is not possible to predict the behaviour of an individual lesion although some clinical and histological features are associated with an increased risk of malignant transformation. The histological features of oral leukoplakia vary considerably, with some lesions having essentially benign appearances while others may show varying degrees of epithelial dysplasia (mild, moderate or severe) or carcinoma in situ. Features of epithelial dysplasia include: • • • • • • • • • • nuclear hyperchromatism loss of polarity increased nuclear–cytoplasmic ratio pleomorphism disordered maturation basal cell hyperplasia drop-shaped rete pegs premature keratinization reduced intercellular adhesion increased or abnormal mitoses. The clinical appearance of such lesions does not allow prediction of the presence or severity of epithelial dysplasia with any degree of certainty, although erythroplakias and nodular leukoplakias are more likely to be dysplastic than homogeneous leukoplakias. Reported rates of malignant transformation vary from 0.3% to 17.5% over periods of about 10 years. In Western Europe an overall figure of 2–6% is considered a realistic estimate of the risk. Factors associated with increased rate of malignant transformation Site of lesion. Floor of mouth, ventral surface of tongue and lingual alveolar mucosa are higher-risk areas and often termed ‘sublingual keratoses’ (Figure 13.5). Some studies have suggested that up to 25% may be invasive carcinoma at time of initial diagnosis and a further 25% will undergo malignant transformation. http://dentalebooks.com O ral m edicine • 309 Figure 13.5 Sublingual leukoplakia. Presence of epithelial dysplasia. The degree of dysplasia is widely believed to be an important factor although there is no definitive proof to support this assertion. Clinical nature of lesion. Nodular or speckled leukoplakias have a higher tendency for malignant transformation than homogeneous leukoplakias. Chronic hyperplastic candidosis (candidal leukoplakia) Homogeneous or nodular white patch lesion most commonly affecting the commissures, although may also involve cheeks, palate or tongue. Male: female, 2: 1. Homogeneous lesions are often asymptomatic whereas nodular lesions may give rise to intermittent discomfort. Frequently associated with other oral candidal lesions (angular cheilitis and Candida-associated denture stomatitis). Predisposing factors. Tobacco usage; nutritional deficiency; poor denture hygiene; corticosteroid inhaler use. Approximately 50% show features of epithelial dysplasia and malignant transformation rates vary from 10 to 40% – significantly higher than for leukoplakia in general. Management. Biopsy is considered mandatory for all white/red lesions, as clinical features are unreliable for diagnostic purposes. Elimination of predisposing factors and systemic antifungal therapy may be prescribed where indicated on histology. Even lesions with no dysplasia on biopsy may contain dysplasia or carcinoma at another location. It is best therefore to remove them. Small lesions or those with features of severe dysplasia should certainly be removed surgically. Long-term follow-up is essential for all such lesions, with periodic biopsy, particularly if there is a change in the appearance or symptomatology of the lesion. Oral submucous fibrosis Insidious chronic disease affecting the oral mucosa; occasionally may extend to involve the pharynx and oesophagus. Characterized by http://dentalebooks.com 310 • C L I N I C A L D E N T I S T RY progressive fibrosis. Occurs almost exclusively in people from the Indian subcontinent and Myanmar although sporadic cases have been reported in other countries. Aetiology unclear – strong association with betel chewing. Tobacco and vitamin deficiencies are other factors. Clinically the mucosa has a blanched opaque appearance with fibrous bands most commonly affecting the lips, buccal mucosa and tongue. Epithelial dysplasia is a common finding; histological evidence of carcinoma observed in 5–6%. Pigmented lesions of the oral mucosa Causes are listed in Table 13.11. Exogenous causes of pigmentation Superficial mucosal staining. May be caused by various foods, betel and tobacco products, and chlorhexidine. TABLE 13.11 Causes of oral mucosal pigmentation Exogenous Endogenous Superficial mucosal staining Developmental Racial Pigmented naevi Peutz–Jeghers syndrome Black hairy tongue Acquired Endocrine associated: Addison’s disease Ectopic ACTH production • • Associated with chronic irritation Drug-induced Associated with HIV infection Melanotic macules Foreign bodies Neoplastic Amalgam tattoo Malignant melanoma Graphite Road grit Heavy metal salts Lead Mercury Bismuth ACTH (adrenocorticotrophic hormone) http://dentalebooks.com O ral m edicine • 311 Black hairy tongue. Benign condition characterized by overgrowth of the filiform papillae together with lack of normal desquamation and associated discoloration, which may vary from brown to black. Discoloration may be related to overgrowth of bacteria and fungi which produce pigment. May be exacerbated by use of tobacco. Generally asymptomatic although some patients become alarmed by the appearance and/or complain of a tickling or gagging sensation due to stimulation of the soft palate. Treatment – reassurance, brushing the tongue with a toothbrush or commercially available tongue scraper. Foreign bodies. (e.g. amalgam, graphite from pencils, road grit following road traffic accident.) Amalgam tattoo characterized by blue/ black area of pigmentation on the mucosa. May occur following fracture of amalgam restoration during extraction of a tooth and inclusion in the healing socket. Alternatively fragments of amalgam may become implanted in the soft tissues during removal of restoration or insertion of retrograde root filling at time of periradicular surgery. Heavy metal salts. (e.g. mercury, lead, bismuth and silver.) Deposition of heavy metal salts along gingival margin in occupationally exposed individuals – now rare. Endogenous causes of pigmentation Melanin is the most common endogenous pigment associated with mucosal pigmentation. Oral lesions associated with the other endogenous pigments (haemosiderin and lipofuscin) are relatively uncommon. Developmental causes of melanin pigmentation. Racial pigmentation, Peutz–Jeghers syndrome (p. 331). Acquired causes of melanin pigmentation Associated with endocrine disease. Addison’s disease, Nelson’s syndrome and tumours secreting ACTH (most commonly bronchogenic carcinoma). Drug-induced. Antimalarials, anticonvulsants, phenothiazines, cytotoxics and oral contraceptives. Reaction to chronic irritation. Most commonly associated with smoking although it may also be seen in lesions that are a response to chronic mechanical trauma, e.g. hyperkeratotic lesions. Melanotic macule. Flat localized area of brown pigmentation often on the lower lip or buccal mucosa. Analogous to a freckle on skin. Associated with HIV infection Neoplastic Malignant melanoma. Highly malignant melanin-containing tumour that may affect skin, mucosa and the eye. Rare tumour in the http://dentalebooks.com 312 • C L I N I C A L D E N T I S T RY oral cavity with most cases involving the posterior hard palate and maxillary alveolar ridge. Most cases occur after the age of 30 years. Usually presents as a deeply pigmented lesion which may be ulcerated and bleeding. Progressively increases in size although growth may be very rapid. Bone involvement is often a prominent feature. Lymph node and distant metastases are common. Treatment is by radical excision but the overall prognosis is poor. Mouth cancer Marked geographic variations in incidence worldwide. In the UK mouth cancer accounts for only 1–2% of all malignant tumours whereas in some parts of India and Sri Lanka it may account for 30–40%. Ninety to 95% of all mouth cancers are squamous cell carcinomas. Mainly seen in middle aged and elderly but as yet unexplained increasing incidence among younger adults. Aetiological factors Tobacco. All forms of smoking tobacco (cigarettes, cigars and pipe smoking) are associated with an increased risk of mouth cancer, particularly if reverse smoking is practised. Chewing betel quid, with added tobacco, accounts for the high incidence of mouth cancer in south Asia. Similarly, use of snuff, chewing tobacco and shisha increases the risk. Alcohol. Increased risk in association with alcohol consumption. Alcohol also acts synergistically with tobacco and multiplies the risk of mouth cancer. Diet and nutrition. Poor diet increases risk. Increased risk of oesophageal and oropharyngeal tumours in patients with Brown Kelly– Paterson syndrome (primary sideropenic anaemia). Ultraviolet light. Important risk factor for carcinoma of the lip. Chronic Candida infection. Chronic hyperplastic candidosis is considered to be a premalignant condition although other chronic Candida infections are not associated with an increased risk of mouth cancer. Human papillomavirus (HPV). Recognized aetiological factor. Approximately 90% of oropharyngeal cancers are linked to HPV infection. Immunosuppression. Increased risk of lip cancer especially among renal transplant recipients. Syphilis. Previously reported association may be related to carcinogenic nature of treatment (e.g. arsenicals). In addition, epithelial atrophy, which is a feature of the later stages of the disease, may render the mucosa more susceptible to carcinogens. Chronic trauma. Mechanical trauma from ill-fitting dentures and a poorly maintained dentition as well as poor oral hygiene have all been http://dentalebooks.com O ral m edicine • 313 Figure 13.6 Carcinoma. suggested as possible aetiological factors, although convincing evidence is lacking. Experimentally, in animals, it has been shown that mechanical trauma can act as a promoter although not an initiator. Thus it is possible that these factors play a similar role in the development of mouth cancer in humans. Clinical features. Clinical presentation varies considerably (Figure 13.6). Early mouth cancers are very often asymptomatic. Common patterns of presentation include the following: Early lesion. Painless solitary ulcer; exophytic growth; white patch; erythroplakia; erythroleukoplakia; chronic crusted lesions on the vermillion border of the lip. Advanced lesion. Pain; exophytic mass; necrotic, bleeding or warty surface; deep, cratered ulcers with indurated edges; bone invasion leading to possible altered sensation and pathological fracture. Prognosis. Factors that are considered to influence the prognosis of mouth cancer are: Early versus late diagnosis. Early diagnosis is by far the most important factor affecting outcome. Extent of disease. Several clinical staging systems exist; the most widely used is the TNM classification (Table 13.12). Site. In general terms, lesions at the back of the mouth have a poorer prognosis than those situated more anteriorly – probably related to later diagnosis of tumours at the back of the mouth. Additionally, early metastasis is a feature of tumours affecting the base of the tongue. In contrast, cancers of the lip have the best prognosis as they are frequently detected at an early stage and are less aggressive tumours. Pathology. The value of histological grading of mouth cancers is controversial due to potential errors in sampling tumours, which are often microscopically heterogeneous. http://dentalebooks.com 314 • C L I N I C A L D E N T I S T RY TABLE 13.12 TNM classification T N M Primary tumour Lymph node status Distant metastases T0 No evidence of primary tumour N0 No nodes involved clinically M0 Absent T1 Greatest diameter <2 cm N1 Single ipsilateral node <3 cm diameter M1 Present T2 Greatest diameter 2–4 cm N2 Single ipsilateral node >3 cm and <6 cm Multiple ipsilateral nodes <6 cm T3 Greatest diameter >4 cm N3 Bilateral nodes or ipsilateral nodes >6 cm T4 Tumour >4 cm with gross local invasion Age. With increasing age, patients are less able to cope with extensive surgery and/or radiotherapy. Diminished cell-mediated response associated with age may also play a role. Treatment. Surgery, radiotherapy and/or chemotherapy. Verrucous carcinoma Regarded as a variety of low-grade squamous cell carcinoma with distinctive clinical appearance and behaviour. Most commonly affects the buccal sulcus and buccal mucosa in the elderly. Established aetiological link with tobacco and betel chewing. Clinical features. Markedly exophytic white plaque-like lesion. Slow growing and erodes rather than invades underlying tissues, including bone. Treatment. Surgical excision is the preferred method of treatment as radiotherapy may induce anaplastic transformation. Miscellaneous lesions Geographic tongue (benign migratory glossitis) Common genetic condition, characterized clinically by irregular partially depapillated areas on the anterior two-thirds of the tongue, often with distinct white margins. These lesions regress and reappear on other parts of the tongue. Frequently asymptomatic although may be some discomfort, particularly on eating hot or spiced foods. http://dentalebooks.com O ral m edicine • 315 Occasionally may affect other parts of the oral mucosa (migratory stomatitis or erythema migrans). If symptomatic, other causes of glossitis should be considered. Fissured tongue (scrotal tongue) Common genetic abnormality which is often associated with geographic tongue. Often asymptomatic and seen frequently in Down syndrome. Clinical features consist of multiple prominent fissures of variable depth. Exclude nutritional deficiency if tongue painful. Also a component of Melkersson–Rosenthal syndrome (triad of fissured tongue, facial nerve palsy and lip/face swelling). Sarcoidosis Granulomatous disorder of unknown aetiology with multisystem involvement. Occurs most commonly in young adults, more common in females. Serum Angiotensin-Converting Enzyme (SACE) level usually elevated. Clinical presentation depends on which organ systems are involved: Lungs. Hilar lymphadenopathy Skin. Erythema nodosum Eyes. Uveitis Heart. Conduction defects Oral. Salivary gland swelling, lip/cheek swelling (orofacial granulomatosis-like picture), hyperplasia of gingivae, painless red nodules. Salivary gland disorders Xerostomia Possible causes. Drug-induced (atropine and atropine analogues, antihypertensive agents, tricyclic antidepressants, phenothiazines, antihistamines, lithium); postirradiation; Sjögren’s syndrome; sarcoidosis; dehydration (e.g. diabetes mellitus, renal failure, fluid loss); HIV salivary gland disease; aplasia of the major salivary glands (very rare); psychogenic (anxiety, depression, hypochondriasis). Sjögren’s syndrome Chronic inflammatory disease with autoimmune basis. Characterized by lymphocytic infiltrate involving exocrine glands. Classified into two types – primary (previously known as sicca syndrome) and secondary. Oral complications of Sjögren’s syndrome include: increased incidence of dental caries, predisposition to oral candidosis, ascending bacterial sialadenitis and an increased incidence of http://dentalebooks.com 316 • C L I N I C A L D E N T I S T RY TABLE 13.13 Features of primary and secondary Sjögren’s syndrome Primary Secondary Connective tissue component Absent Present Xerostomia More severe Less severe Recurrent sialadenitis More common Less common Xerophthalmia Severe Less severe Rheumatoid factor positive 50% 90% Anti-Ro positive 5–10% 50–80% Anti-La positive 50–70% 2–5% lymphoma. The incidence of lymphoma is greatest among patients with primary Sjögren’s syndrome. Clinical features. see Table 13.13. Primary. Xerostomia (dry mouth), xerophthalmia (dry eyes). Secondary. Xerostomia, xerophthalmia, connective tissue disorder – most commonly rheumatoid arthritis. Other possible connective tissue disorders include systemic lupus erythematosus, primary biliary cirrhosis, mixed connective tissue disorder. Investigation and diagnosis. No single test will consistently and reliably establish the diagnosis although the following investigations may provide supportive evidence of a positive diagnosis of Sjögren’s syndrome: salivary flow rate (whole salivary flow rate ≤ 0.1 ml/min); Schirmer test – assesses lacrimal flow (positive if ≤5 mm wetting in 5 min); immunological investigations – rheumatoid factor, antinuclear factor, anti-Ro (SS-A) and anti-La (SS-B); sialography – variable degrees of sialectasis are found in patients, although this abnormality is not specific; ultrasound showing multiple hypo-echoic areas; scintigraphy – both uptake and excretion of the radioactive isotope sodium pertechnetate is diminished; labial gland biopsy – histological features which support the diagnosis include focal lymphocytic sialadenitis, duct dilation, acinar loss and periductal fibrosis. American– European diagnostic criteria are summarized in Table 13.14. The American College of Rheumatology criteria are summarized in Table 13.15. Treatment. Treatment is largely non-specific and simply aimed at controlling symptoms. Maintain adequate hydration. Commercially available salivary substitutes – mouth-wetting agents (e.g. Oralbalance gel, Saliva Orthana and Glandosane, Xerotin). Salivary stimulants: chewing gum, glycerine and lemon (but avoid in dentate patients due to low pH). Pilocarpine or cevimeline act as systemic salivary stimulants and may prove useful, although clearly patients http://dentalebooks.com O ral m edicine • 317 TABLE 13.14 American–European classification criteria for Sjögren’s syndrome I II Ocular symptoms – a positive response to at least one of the following questions: Have you had daily, persistent, troublesome dry eyes for at least 3 months? Do you have a recurrent sensation of sand or gravel in the eyes? Do you use tear substitutes more than three times a day? Oral symptoms – a positive response to at least one of the following questions: Have you had a daily feeling of a dry mouth for more than 3 months? Have you had recurrently or persistently swollen salivary glands as an adult? Do you frequently drink liquids to aid swallowing dry food? Ocular signs – objective evidence of ocular involvement defined as positive result in at least one of the following two tests: Schirmer test (≤5 mm in 5 min) Rose Bengal score ≥4 (van Bijsterveld’s scoring system) Histopathology – a focus score of >1 on labial gland biopsy A focus is defined as an agglomerate of at least 50 mononuclear cells; the focus score is defined by the number of foci in 4 mm2 of glandular tissue Salivary gland involvement – objective evidence of salivary gland involvement, defined as a positive result in at least one of the following investigations: Unstimulated salivary flow (<1.5 ml in 15 min) Salivary gland scintigraphy demonstrating reduced uptake and/or excretion Sialography demonstrating sialectasis Autoantibodies – the following autoantibodies present in serum: Antibodies to Ro (SS-A) and/or La (SS-B) antigens • • • • • • III • • IV V • • • VI In patients without any potential associated connective tissue disorder the presence of any four of the above six items is indicative of primary Sjögren’s syndrome. In patients with a connective tissue disorder, item I or item II together with two other items from III, IV and V is indicative of secondary Sjögren’s syndrome. TABLE 13.15 American College of Rheumatology classification criteria for Sjögren’s syndrome At least two of the following three findings:Positive anti-Ro and/or anti-La antibodies or positive rheumatoid factor and antinuclear antibody titre of at least 1 : 320 Ocular staining score of at least 3 Presence of focal lymphocytic sialadenitis with a focus score of at least 1 focus/4 mm2 in labial salivary gland biopsy • • • http://dentalebooks.com 318 • C L I N I C A L D E N T I S T RY must have some residual functional salivary gland tissue. Preventive dental care – fluoride rinses and avoidance of sugary foodstuffs. Denture hygiene measures because of increased risk of candidosis. Treat acute episodes of bacterial sialadenitis with appropriate antibiotics. Long-term follow-up indicated in view of increased incidence of lymphoma, which may present as persistent salivary gland swelling. Salivary gland neoplasms Relatively uncommon – constitute only 3% of all tumours. Approximately 80% occur in the major glands, 20% in minor glands. Overall, while only a minority of tumours occur in minor glands there is a greater proportion of malignant tumours in minor glands than in major glands. While tumours of the submandibular, sublingual and minor glands are less common than parotid tumours, there is an increased risk of malignancy at these sites. Table 13.16 gives the classification of salivary gland tumours. Pleomorphic adenoma Most common salivary gland tumour (60% of all parotid tumours and 45% of all minor gland tumours); 90% occur in the parotid, with the tail of the parotid being the favoured site. Most patients in fifth and sixth decades. Slightly more common among females. Painless, slow-growing rubbery mass. As the name implies there is considerable variation in histological features, with intermingled epithelial elements and mesenchymal tissue. Connective tissue capsule is poorly developed in some areas with outgrowths of the main tumour mass extending beyond the capsule. Monomorphic adenomas Various subtypes according to histological pattern. Less common than pleomorphic adenomas (20% of all parotid tumours, 10% of minor gland tumours). TABLE 13.16 Classification of salivary gland tumours Benign Malignant Pleomorphic adenoma Monomorphic adenomas: adenolymphoma oxyphilic basal cell tubular clear cell trabecular, etc. Mucoepidermoid carcinoma Acinic cell carcinoma Adenoid cystic carcinoma Polymorphous low-grade adenocarcinoma Carcinoma arising in pleomorphic adenoma • • • • • • http://dentalebooks.com O ral m edicine • 319 Adenolymphoma Most common of the monomorphic adenomas. Most patients >50 years; male: female, 1.5: 1. Vast majority occur in the parotid. Bilateral in up to 10% of cases. Painless, firm to palpate. Clinically indistinguishable from other benign parotid tumours. Well-encapsulated, papillary cystic structure with two histological components, namely epithelial and lymphoid tissue. Mucoepidermoid carcinoma Accounts for 5% of all salivary neoplasms. Occurs mainly in parotid. Peak incidence fourth and fifth decades. More common in females. Variable grades of malignancy, which influences rate of growth. Low-grade tumours usually present as painless, slowly enlarging lesions not unlike a pleomorphic adenoma. Tumours of high-grade malignancy grow rapidly and local pain may be an early feature. Facial nerve paralysis may also occur. Lymph node and distant metastases common. Prognosis influenced by grade of tumour. Acinic cell carcinoma Uncommon tumour arising mainly in parotid. Clinical presenta­ tion is similar to that of a pleomorphic adenoma. Behaviour unpredictable. Adenoid cystic carcinoma Usually affects middle-aged and elderly; accounts for 15% of minor gland tumours, 2–3% of parotid tumours. Slow-growing tumour which may initially be clinically indistinguishable from a pleomorphic adenoma. Local pain, ulceration of overlying mucosa, fixation to deeper structures and facial nerve palsy (in case of parotid tumour) may be features. Widely infiltrative with perineural spread. Cribriform or ‘Swiss cheese’ pattern. Carcinoma arising in pleomorphic adenoma Most arise in parotid tumours that have been present for 10–15 years. Characteristic sudden increase in rate of growth. Salivary mucoceles Two types: Mucous extravasation cysts. Account for 90% of cases and occur as a result of extravasation of mucus from a damaged minor gland duct. Mucous retention cysts. Less common and due to retention of mucus within a salivary gland or duct. Clinical features. Most cases arise in the lower lip, although less commonly may affect buccal mucosa, floor of mouth and tongue. http://dentalebooks.com 320 • C L I N I C A L D E N T I S T RY Extremely uncommon in upper lip. Painless, bluish translucent, fluctuant submucosal swelling. Readily ruptured to release viscous mucus. Recurrence common. Treatment. If symptomatic – excision with underlying minor gland. Bacterial sialadenitis Usually occurs in association with local (e.g. calculus, mucus plug or duct stricture) or systemic causes of reduced salivary flow (e.g. diabetes mellitus, Sjögren’s syndrome or following radiotherapy). Previously a relatively common postoperative complication due to dehydration, although this is now rare. Ascending infection from oral flora. The main organisms involved are Staphylococcus aureus, α-haemolytic streptococci, Streptococcus viridans and anaerobes. Clinical features. Pain and swelling of the affected gland. Associated pyrexia, malaise, cervical lymphadenopathy and occasional erythema of the overlying skin. Pus may be expressed from the involved gland duct orifice. Investigation and diagnosis. Pus for culture and sensitivity. Treatment. Antibiotics (flucloxacillin is the drug of choice, or erythromycin if the patient has an allergy to penicillin). Encourage drainage by use of sialogogues. General supportive measures such as ensuring adequate fluid intake and analgesia. After acute infection has resolved, sialography should be performed to exclude predisposing factors such as calculi, mucus plugs or duct strictures. Mumps Common viral infection caused by a paramyxovirus which predominantly affects children. Transmitted by droplet spread. Incubation period of 14–21 days. Clinical features. Prodromal fever, malaise, trismus and sore throat followed by acute, tender, usually bilateral, swelling of the parotid glands. In a minority of cases the submandibular glands may be involved. Usually self-limiting and resolves within a week although, rarely, complications such as pancreatitis, encephalitis, orchitis or oophoritis may develop. Investigation and diagnosis. Usually based on characteristic history and clinical features. Diagnosis can be confirmed by serology (elevated IgM to ‘S’ and ‘V’ antigens). Treatment. Bed rest, analgesia, antipyretic and adequate fluid intake. http://dentalebooks.com O ral m edicine • 321 Sialosis (Sialadenosis) Uncommon benign, non-inflammatory, non-neoplastic swelling of major salivary glands, most commonly affecting parotid glands although may also affect submandibular glands. Generally idiopathic although recognized associations include the following: druginduced (e.g. isoprenaline, phenylbutazone and antithyroid agents); diabetes mellitus; thyroid disease; pregnancy; malnutrition; anorexia and bulimia nervosa; cirrhosis and liver disease. Clinical features. Usually soft, non-tender bilateral swelling of the parotid glands. Histological features. Include serous acinar hypertrophy, oedema of the interstitial stroma and striated duct atrophy. Management. Identify and correct predisposing factors if possible. Effects of drugs on the teeth, oral mucosa and salivary glands Discoloration of teeth. Chlorhexidine; tetracycline; iron; tobacco; betel. Oral candidosis. Broad-spectrum antibiotics; corticosteroids (systemic and topical); cytotoxic drugs. Oral ulceration. Cytotoxic agents; aspirin applied topically; penicillamine; nicorandil. Gingival swelling. Phenytoin; calcium channel blockers (e.g. nifedipine, diltiazem); ciclosporin. Erythema multiforme. Sulphonamides; barbiturates; penicillin; carbamazepine; biological agents. Lichenoid reactions. Oral hypoglycaemic agents; non-steroidal anti-inflammatory agents; beta-blockers; diuretics; allopurinol; methyldopa. Mucosal pigmentation. Antimalarials (e.g. mepacrine, chloroquine); phenothiazines; oral contraceptives. Xerostomia. Antihistamines; tricyclic antidepressants; monoamine oxidase inhibitors; diuretics; anticholinergic agents (e.g. atropine-like drugs); anti-Parkinsonian agents (e.g. benzhexol, benzatropine). Salivary gland pain and swelling. Phenothiazines; antithyroid drugs; insulin. Disorders of the temporomandibular joint (TMJ) See also craniomandibular disorders (Chapter 14). http://dentalebooks.com 322 • C L I N I C A L D E N T I S T RY Common disorders of the TMJ • • • • Myofascial pain dysfunction syndrome Internal joint derangement Degenerative disorders, e.g. osteoarthrosis Trauma. Rare disorders of the TMJ • • • • Inflammatory – infection, rheumatoid arthritis, psoriatic arthropathy Ankylosis Congenital problems Neoplasms. Craniomandibular disorders are complex from a diagnostic and management viewpoint. For this reason, patients are probably best treated in a combined clinic where experts in oral medicine and surgery, restorative dentistry and pain management formulate a common approach to patient management. Myofascial pain dysfunction syndrome Very common problem. Multiplicity of synonymous terms: TMJ pain dysfunction syndrome; craniomandibular dysfunction; facial arthromyalgia; mandibular stress syndrome; mandibular dysfunction. Widely considered to be more common in females, although this is a misconception and is a simple reflection of more females seeking treatment. Epidemiological studies suggest that there is equal prevalence in males and females. Symptoms. Dull intermittent or continuous ache, localized to muscle area. Pain may increase in severity with function. Headache is often an associated feature. Signs. Tenderness on palpation over muscles, which may elicit patient’s symptoms. May be limitation of mandibular movement. Possible evidence of clenching or grinding habit (wear facets). Treatment options. Explanation and reassurance; physiotherapy (e.g. short-wave diathermy, ultrasound); occlusal splint therapy (wide variety of splints suggested); pharmacotherapy (NSAIDs and/ or tricyclic antidepressant). Anterior disc displacement with reduction Symptoms. Joint noises. The presence of pain around the joint is a variable feature. http://dentalebooks.com O ral m edicine • 323 Signs. Click on opening and closing (reciprocal click). Full range of movement. Treatment. Normally no treatment other than reassurance required. Acute anterior disc displacement without reduction Symptoms. Acute onset of limitation of opening. Previous history of opening click that suddenly resolved. Pain on opening is a variable feature. Signs. Opening less than 35 mm. Contralateral excursion of the mandible less than 7 mm. Unassisted opening within 4 mm of assisted opening. Deviation to affected side on opening. Chronic anterior disc displacement without reduction Symptoms. Significant limitation of opening for a variable period. Previous history of joint click. Signs. Opening >35 mm. Assisted opening >5 mm more than unassisted opening. Treatment. Occlusal splint therapy, muscle relaxant (e.g. dosulepin), arthroscopy, surgery. Osteoarthrosis TMJ may be affected in up to one-third of cases. Characterized by crepitus and pain localized to the preauricular area with no radiation. Limitation of movement which becomes more apparent with function. Changes in the condylar head are apparent radiographically. Treatment is not usually surgical but aimed at symptomatic relief (e.g. NSAIDs and intra-articular corticosteroid injections). Rheumatoid arthritis Approximately 70% of patients with rheumatoid arthritis have clinical and/or radiographic evidence of TMJ involvement, although this is rarely symptomatic. Other causes of arthrosis are psoriasis, gout and ankylosing spondylitis. Treatment is as for osteoarthrosis and physiotherapy may be of benefit. Facial pain Burning mouth syndrome (oral dysaesthesia) Burning sensation or other abnormal sensation affecting the oral soft tissues in the absence of clinically evident mucosal disease. http://dentalebooks.com 324 • C L I N I C A L D E N T I S T RY More commonly affects females (F: M, 7: 1). Classified into three broad types according to temporal pattern of symptoms: Type 1. Asymptomatic on waking; symptoms increase in severity during the day. Associated with a good prognosis. Type 2. Symptoms present on waking and continue throughout the day. Often associated with significant anxiety or depressive element. Prognosis poorer than Type 1. Type 3. Intermittent symptoms and often involves unusual sites, e.g. floor of mouth. May be associated with aetiological factors such as allergy. Aetiological factors in oral dysaesthesia are summarised in Table 13.17. Investigation. Haematological investigations (FBC, assays of ferritin, folate and vitamin B12) to exclude nutritional deficiency. Random blood glucose to exclude diabetes. (In known diabetics glycosylated haemoglobin can be used as an assessment of glycaemic control.) Microbiology for Candida. Prosthodontic assessment. Evaluation of psychological status (anxiety and depression). If an allergic component is suspected, arrange patch testing although this is an uncommon cause. TABLE 13.17 Aetiological factors in oral dysaesthesia (‘burning mouth syndrome’) Nutritional deficiencies Iron, folate and vitamin B12 Vitamins B1 and B6 Undiagnosed or poorly controlled diabetes mellitus Denture factors Inadequate tongue space Unstable dentures Inadequate freeway space Hypersensitivity to acrylic monomer Mucosal infections Candidosis and candidal carriage Hyposalivation Parafunctional activity Tongue thrusting Clenching Bruxism Psychological factors Anxiety Depression Cancer phobia Drugs Captopril Allergy Denture base materials Food additives http://dentalebooks.com O ral m edicine • 325 Treatment. Reassure patient regarding the benign nature of the problem. Correct underlying organic predisposing factors. If symptoms persist following correction of above and a psychogenic element is suspected, antidepressant drug therapy is often helpful in con­ rolling symptoms. In such cases a tricyclic antidepressant (e.g. amitriptyline, nortriptyline or dosulepin) is the drug of choice. Persistent idiopathic facial pain Essentially a diagnosis of exclusion. International Headache Society Diagnostic criteria: • • • • pain in the face, present daily and persisting for all or most of the day pain confined at the outset to one side of the face; deep and poorly localized pain not associated with sensory loss or other physical signs pain investigations including radiography do not identify any relevant abnormality. While the pain is generally not sufficiently severe to disturb sleep, patients may report early morning wakening as part of a depressive element. Atypical odontalgia is considered to be a variant of persistent idiopathic facial pain. Predominantly affects females in the fourth or fifth decade of life. Clinical features. No organic cause to explain pain. High incidence of depression and anxiety. Treatment. Tricyclic antidepressant (e.g. dosulepin or amitriptyl­ ine) or selective serotonin reuptake inhibitor (e.g. fluoxetine or venlafaxin). Trigeminal neuralgia A true neuralgia is characterized by severe paroxysmal pain lasting seconds in the distribution of one or more branches of the trigeminal nerve. Most commonly affects the maxillary or mandibular divisions with less than 5% of cases affecting the ophthalmic division. Most patients are >50 years although it rarely occurs in younger age groups. Pain is often described as like an electric shock, lancinating, stabbing or piercing in nature. Some patients describe a trigger zone which may be either extraoral or intraoral. Thus patients may avoid washing or shaving a particular area on the face for fear of precipitating an attack of pain. Clinical features. Normal examination apart from possible presence of trigger area. http://dentalebooks.com 326 • C L I N I C A L D E N T I S T RY TABLE 13.18 Treatment options in trigeminal neuralgia Medical Surgical Carbamazepine Peripheral nerve procedures Bupivacaine, alcohol or glycerol injections Cryosurgery of peripheral nerve Neurectomy Procedures involving trigeminal nerve ganglion Alcohol or glycerol injection Fogarty balloon compression Radiofrequency thermocoagulation Central procedures Microvascular decompression of main sensory root (Janetta procedure) Rhizotomy Oxcarbazepine Gabapentin Phenytoin Valproate Investigation and diagnosis. Exclude odontogenic source for pain. Response to carbamazepine is generally diagnostic. Presence of abnormal neurological signs should raise the suspicion that the pain is due to underlying CNS pathology. In young individuals it may be indicative of underlying systemic disease, e.g. multiple sclerosis or posterior cranial fossa tumour. Thus an MRI scan may be indicated in younger patients and in those who do not respond to medical therapy. Treatment. Treatment options are listed in Table 13.18. Glossopharyngeal neuralgia Uncommon condition characterized by severe lancinating pain in the distribution of glossopharyngeal nerve. Thus pain experienced in the base of the tongue and pillars of fauces. May be triggered by swallowing, coughing and chewing. Treatment based on principles similar to those for trigeminal neuralgia. Giant cell arteritis (Temporal or cranial arteritis) Vascular pain syndrome which predominantly affects older patients and manifests as unilateral temporal and/or jaw pain, often reported as a burning sensation. May affect any artery in the head and neck, often the temporal and occipital branches of the external carotid. Involvement of retinal or ciliary vessels may cause blindness. Clinical features. Affected arteries may be thickened or tender and may show diminished pulsation. Claudication involving the muscles of mastication may also be a feature. May be associated with fever, malaise, anorexia and weight loss. May be part of polymyalgia rheumatica. http://dentalebooks.com O ral m edicine • 327 Investigation and diagnosis. Elevated ESR and C-reactive protein levels during acute phase. Normochromic, normocytic anaemia in 50% of cases. Temporal artery biopsy demonstrates infiltration of arterial wall with giant cells. The typical histological features do not affect the artery uniformly and therefore a negative result does not exclude the diagnosis. Early diagnosis and treatment is important in view of the potentially serious ophthalmic complications. Treatment. Systemic corticosteroids without delay – high-dose prednisolone (60–80 mg daily). Periodic migrainous neuralgia (cluster headache) Characterized by severe unilateral pain predominantly affecting the orbital, supraorbital or temporal regions. Males more commonly affected. Pain occurs in discrete bouts, each typically lasting 30−90 minutes, and is often sufficiently severe to waken patient. Episodes often accompanied by rhinorrhoea, nasal congestion, lacrimation, facial sweating or conjunctival injection. Most patients appear agitated or restless during attacks. Some patients report that alcohol may be a precipitant. Episodes occur in bouts which can last for several days or weeks and then are followed by a variable period of remission. Treatment. Treatment can be considered under two headings: treatment of acute episode and prophylaxis. Acute episode. Sumatriptan, oxygen. Prophylaxis. Indometacin, beta-blockers, methysergide, calcium channel blockers, lithium. Oral manifestations of systemic disease Oral manifestations of skin disease Lichen planus and lichenoid reactions Lichen planus is a common mucocutaneous disorder involving skin and/or oral mucosa, mainly affecting middle-aged and elderly females. Oral lesions are seen in about 50% of patients presenting with skin lesions while skin lesions are seen in only 10–30% of those presenting with oral manifestations. Skin lesions generally resolve within 18 months whereas oral mucosal lesions have a more chronic course, often persisting for several years. While most cases of oral lichen planus follow an entirely benign course, malignant transformation has been reported in a small proportion of cases and this appears to be more common in the atrophic and erosive types. Most studies quantify the risk of malignant transformation as approximately 1% over a 5–10 year period. (For aetiology, see Table 13.19.) http://dentalebooks.com 328 • C L I N I C A L D E N T I S T RY TABLE 13.19 Factors suggested as important in the aetiology of lichen planus Exogenous factors Systemic factors Dental materials, e.g. amalgam, mercury, gold Graft versus host disease Nutritional deficiencies Diabetes mellitus Liver disease Food allergens Drugs e.g. diuretics, β-blockers, NSAIDs, oral hypoglycaemics Infection Bacterial plaque Candida Stress Tobacco Trauma • • Figure 13.7 Lichen planus (papulo-reticular type). Clinical features. Cutaneous lesions are characterized by itchy, violaceous, polygonal papular lesions with fine white streaks on the surface (Wickham’s striae). The most common sites are the flexor aspect of the wrists, forearms and legs. Skin lesions may be induced by trauma (Koebner phenomenon). Nail involvement occurs in around 10% of cases and hair loss may also be a feature. Lichenoid reactions have similar clinical features as lichen planus and in many cases it may be impossible to differentiate between the two lesions. Asymmetrical lesions, palatal involvement and recent drug therapy may be suggestive of a lichenoid reaction rather than lichen planus. Several patterns of oral lesions are recognized although different variants may coexist in the same patient (Figure 13.7): Reticular. Most common variant characterized by fine lace-like network of white striae; usually present bilaterally on the buccal mucosa and less commonly on the lateral margins of the tongue. Frequently asymptomatic. Papular. Relatively uncommon. Small white papules usually on the buccal mucosa. http://dentalebooks.com O ral m edicine • 329 Plaque. Lesions resemble leukoplakia although a reticular pattern may often be observed at the periphery of the lesion. Atrophic. Diffuse erythematous areas, often with reticular lesions at edges. Erosive or ulcerative. Painful, irregular, persistent superficial erosions of variable size. Often coexists with non-erosive lesions. Bullous. Very rare variant. Desquamative gingivitis. A common variant affecting the gingivae. Histological features. Acanthotic or atrophic epithelium; liquefaction degeneration of the basal cell layer; inflammatory cell infiltrate in the deeper layers of the epithelium; dense subepithelial band of chronic inflammatory cells (predominantly T lymphocytes) with well-defined lower border. Treatment. Asymptomatic lesions require no active treatment. A wide variety of treatments have been advocated for management of symptomatic lesions although none is universally successful. Treatment options are listed in Table 13.20. Lupus erythematosus Several different forms exist; on this basis it is classified into two main types: 1. Systemic lupus erythematosus (SLE) 2. Chronic discoid lupus erythematosus (CDLE). Systemic lupus erythematosus (SLE) An autoimmune disorder largely of unknown aetiology although a few cases may be drug induced (hydralazine, phenytoin). Females more commonly affected (F: M, 9: 1). Characterized by the presence TABLE 13.20 Treatment options for symptomatic lichen planus Antiseptic mouthwashes: chlorhexidine gluconate benzydamine hydrochloride Corticosteroids: Topical: betamethasone beclometasone Intralesional: triamcinolone Systemic: prednisolone Azathioprine Tacrolimus (topically) http://dentalebooks.com 330 • C L I N I C A L D E N T I S T RY of non-organ-specific autoantibodies and widespread clinical manifestations which may involve virtually all tissues. Features typically include a photosensitive erythematous skin rash over the nose and malar eminences (butterfly pattern), arthritis and anaemia, although cardiac, respiratory, renal, hepatic, pancreatic and neurological manifestations may also occur. Thus the actual clinical presentation varies according to which organs are involved. Oral lesions may be seen in up to one-third of patients and are similar to those of lichen planus with erythematous lesions and superficial erosions. Erosive oral lesions are often difficult to treat and may only respond to high-dose systemic corticosteroids. Sjögren’s syndrome may also be a complication of the disease. Chronic discoid lupus erythematosus (CDLE) Predominantly a mucocutaneous disorder with no systemic abnormalities. Similar butterfly rash to that seen in SLE. In addition ears, scalp and hands may be affected. Typical skin lesions consist of welldefined scaly erythematous macules which may heal by scarring and leave areas of hypopigmentation. Oral lesions occur in up to 50% of patients. Buccal mucosa and vermillion border of the lip are common sites. Classically oral lesions consist of a central erythematous or erosive area with peripheral radiating white striae. Oral lesions generally respond to treatment with topical corticosteroids. Vesiculobullous disorders See p. 301. Oral manifestations of gastrointestinal disease Crohn’s disease A chronic granulomatous disorder of unknown aetiology originally described as affecting the terminal ileum although it is now recognized that the disease can affect any part of the gastrointestinal tract from mouth to anus. General symptoms include abdominal pain, pyrexia, malaise, weight loss and disturbance of bowel habit with rectal bleeding. Extra-intestinal manifestations (e.g. erythema nodosum, arthritis and uveitis) are also recognized. Oral lesions may predate the development of bowel symptoms or may be the only feature of the disorder. Clinical features. Recurrent ulcers; diffuse lip or cheek swelling; cobblestone appearance of buccal mucosa; mucosal tags; full-width gingivitis; granulomatous angular cheilitis; vertical fissures of the lips. Orofacial granulomatosis (OFG) Clinical and histological features identical to those of oral Crohn’s disease and considered to be a diagnosis of exclusion (Crohn’s disease, http://dentalebooks.com O ral m edicine • 331 sarcoidosis). Increasing evidence to suggest that OFG is a hypersensitivity response to dietary and/or environmental allergens, particularly benzoic acid and cinnamon. Ulcerative colitis Chronic inflammatory disorder of unknown aetiology affecting the colon. Clinical features. Characterized by diarrhoea, passage of blood and mucus per rectum, weight loss and abdominal pain. Arthritis, uveitis and erythema nodosum may also be features of the disease. Oral lesions may occur and include: recurrent oral ulceration (secondary to nutritional deficiency or specific effect of underly­ ing disease process); pyostomatitis gangrenosum; pyostomatitis vegetans. Treatment. Specific treatment of the underlying intestinal disease often results in improvement in oral lesions. Brown Kelly–Paterson syndrome (Plummer–Vinson syndrome) Uncommon syndrome occurring principally in postmenopausal women. Components of the syndrome: dysphagia due to postcricoid web, which is premalignant; iron deficiency anaemia with glossitis, koilonychia and angular cheilitis. Gardner syndrome Autosomal dominant condition. Hard tissue ‘tumours’. Bony exostoses, compound odontomes and/ or supernumerary teeth. Soft tissue ‘tumours’. Sebaceous cysts, subcutaneous fibromas, polyposis of the large intestine which almost invariably undergoes malignant change. Peutz–Jegher’s syndrome Autosomal dominant condition. Mucocutaneous pigmentation; skin pigmentation may fade in adult life although mucosal pigmentation persists. Intestinal polyposis with low malignant potential, which principally affects the small bowel. Oral manifestations of neurological disease Facial nerve palsy The upper part of the face receives bilateral upper motor neurone innervation from both cerebral hemispheres whereas the lower part of the face receives upper motor neurone innervation only from the http://dentalebooks.com 332 • C L I N I C A L D E N T I S T RY TABLE 13.21 Causes of trigeminal nerve sensory loss Intracranial Extracranial Multiple sclerosis Trauma to peripheral branches of trigeminal nerve Connective tissue diseases Cerebral tumours Osteomyelitis Cerebrovascular diseases Benign trigeminal neuropathy Paget’s disease Neoplasia Carcinoma of nasopharanx Carcinoma of the maxillary antrum Sarcoidosis Leukaemic deposits • • contralateral hemisphere. Thus an upper motor neurone lesion affects only the lower part of the face on the opposite side while a lower motor neurone lesion affects the whole of the face on the same side. Upper motor neurone lesions. Cerebrovascular accident; multiple sclerosis. Lower motor neurone lesions. Bell’s palsy; trauma; cerebellopontine angle tumours; malignant parotid gland tumour; otitis media; sarcoidosis; Lyme disease (Borellia burgdoferii infection). Sensory loss See Table 13.21 for causes. Bell’s palsy Acute onset over several hours. Some patients report pain 1 or 2 days before onset of facial paralysis. Most patients recover spontaneously over a period of several weeks. Protect cornea while palsy is present. If patient seen within 5 days of onset, systemic corticosteroids may reduce the likelihood of incomplete recovery – prednisolone 80 mg daily for 5 days and tail off dose over the next 5 days. Recent evidence implicates herpes simplex virus in many cases. However, studies confirm that there is no added benefit by adding aciclovir. Oral manifestations of haematological disease Anaemia Reduction in the concentration of haemoglobin below the normal level considering age and gender of the patient. http://dentalebooks.com O ral m edicine • 333 Oral features include: recurrent oral ulceration; atrophic glossitis; angular cheilitis; candidosis; oral dysaesthesia; Brown Kelly–Paterson syndrome. Leukaemias Neoplastic proliferation of white cell precursors which may occur in either acute or chronic forms. Cells affected include lymphocytes, monocytes or granulocytes. In general oral lesions in acute leukaemia are more common and more severe than those seen in association with chronic leukaemias. Oral problems include: bleeding and petechial haemorrhage; mucosal pallor; increased predisposition to infections (e.g. candidosis, herpes); ulceration; gingival swelling. Myeloma Disseminated malignant neoplasm of plasma cells. Principally affects middle-aged and elderly with slight male predominance. Multiple discrete osteolytic lesions in the skull and, less commonly, jaws. Macroglossia due to infiltration with amyloid. Leucopenia Reduced numbers of total circulating white blood cells (<4 × 109/l). Possible causes include leukaemia, aplastic anaemia, drug-induced, autoimmune disease, HIV infection. Oral lesions include increased susceptibility to infection, mucosal ulceration and exacerbation of periodontal disease. Cyclic neutropenia Rare form of leucopenia characterized by reduction in neutrophil count in 3–4-week cycles. Oral problems are as above. HIV infection and acquired immune deficiency syndrome (AIDS) Oral lesions are common in HIV-seropositive patients. In general they are not specific to HIV infection and simply reflect the immunocompromised state. Thus many of the oral lesions also occur in patients who are immunosuppressed for other reasons. The prevalence of oral lesions among HIV-seropositive patients is dramatically reduced by highly active Anti-Retroviral Therapy (ART). The current classification of these lesions is based on the strength of association with HIV infection (Table 13.22). Three groups are recognized: Group I. Lesions strongly associated with HIV infection http://dentalebooks.com 334 • C L I N I C A L D E N T I S T RY TABLE 13.22 Lesions associated with HIV infection Group I: lesions strongly associated with HIV infection Candidosis: erythematous pseudomembranous angular cheilitis median rhomboid glossitis • • • • Hairy leukoplakia Kaposi’s sarcoma Non-Hodgkin’s lymphoma Periodontal diseases: linear gingival erythema acute necrotizing ulcerative gingivitis acute necrotizing ulcerative periodontitis • • • Group II: lesions less commonly associated with HIV infection Atypical ulceration HIV-associated salivary gland disease (HIV-SGD): Xerostomia and/or swelling of the major salivary glands • Necrotizing ulcerative stomatitis Thrombocytopenic purpura Viral infections: Cytomegalovirus Herpes simplex virus Human papillomavirus Varicella zoster • • • • Group III: lesions seen in HIV infection Bacterial infections Drug reactions Fungal infections Neurological disturbances: Facial nerve palsy Trigeminal neuropathy • • Group II. Lesions less commonly associated with HIV Group III. Lesions seen in HIV infection. Erythematous and pseudomembranous candidosis Most common oral fungal infections seen in association with HIV infection. Various studies report the frequency of oral candidosis as ranging from 7 to 93%. Erythematous candidosis generally occurs early in the disease process whereas pseudomembranous candidosis is a later manifestation, occurring when the patient is severely immunosuppressed. Both forms are highly predictive of the development of AIDS. Clinical features of fungal infections. http://dentalebooks.com O ral m edicine • 335 Hairy leukoplakia Usually asymptomatic. Characterized by bilateral vertically corrugated white patches on the lateral margins of the tongue. May affect the ventral surface, where it assumes a more homogenous appearance. Rarely may involve other parts of the oral mucosa (buccal mucosa and palate) although when it affects these unusual sites it is also always present on the lateral margin of the tongue. Originally considered to be pathognomonic of HIV infection, although as the lesion has been described in other immunosuppressed patient groups (e.g. organ transplant recipients, patients receiving chemotherapy for acute leukaemia) it is now simply regarded as a marker of underlying immunodeficiency. Characteristic histological features; believed to represent an opportunistic infection of the oral mucosa by EBV. Definitive diagnosis is by detecting presence of EBV within the lesional tissue by in-situ hybridization. May respond to treatment with aciclovir although when treatment is discontinued the lesion inevitably recurs. Marker of poor prognosis in HIV-infected patients. Kaposi’s sarcoma Before the advent of AIDS and HIV infection Kaposi’s sarcoma (KS) was seen mainly among elderly Jewish males of eastern European or Mediterranean descent, and an endemic form was recognized in southern Africa. AIDS-associated KS is seen almost exclusively in men who have sex with men (MSM) and is rare among other risk categories for HIV infection. Presents as red or purple maculopapular lesions. Approximately 50% occur intra- or periorally with the most common site in the mouth being the junction of hard and soft palate. Caused by infection with human herpes virus 8 (HHV8). KS is usually very responsive to radiotherapy. Alternative treatments include chemotherapy (systemic and intralesional), surgical excision, laser excision and cryosurgery. Non-Hodgkin’s lymphoma Uncommon but well-recognized complication of HIV infection. Typically presents as a rapidly enlarging, firm, rubbery swelling. Common intraoral sites include fauces, palate and gingivae. Lesions can ulcerate and may be associated with destruction of tooth support. Treatment is generally with radiotherapy and/or chemotherapy. Linear gingival erythema Characterized by an intense linear band of erythema along the gingival margin, which may also extend onto the attached gingivae. Severity of inflammation is out of proportion to the state of oral hygiene. Spontaneous gingival bleeding may also be a feature. http://dentalebooks.com 336 • C L I N I C A L D E N T I S T RY TABLE 13.23 Causes of halitosis (oral malodour) Xerostomia Periodontal disease Oropharyngeal sepsis Nasal sepsis (e.g. sinusitis or foreign body) Smoking Various foodstuffs (e.g. garlic, onions) Drugs Systemic disease (diabetes, respiratory tract infection, renal failure, hepatic failure) Psychogenic Acute necrotizing ulcerative gingivitis Characterized by gingival pain, bleeding on probing or spontaneous bleeding and interdental ulceration with crater-like defects. Acute necrotizing periodontitis Rapid localized or generalized periodontal destruction with severe pain, bone loss, tooth mobility and periodontal pocketing. HIV salivary gland disease More common in HIV-infected children than adults. Characterized by xerostomia and/or swelling of the major salivary glands. Clinical parallels with Sjögren’s syndrome although characteristic autoantibody profile is lacking. Histological features similar to Sjögren’s syndrome. Halitosis (Oral malodour) Relatively common complaint with a wide variety of possible causes summarized in Table 13.23. Where sepsis is responsible the organisms are usually anaerobic. In some patients there is no objective evidence of malodour and the patient’s perception of halitosis may be a manifestation of an underlying psychogenic problem. Diagnosis. Largely clinical based on history and examination. Overall assessment of the halitosis can be undertaken by simply smelling the exhaled breath or objective measurement of volatile sulphur compounds (e.g. hydrogen sulphide and methyl mercaptan) using a halimeter. Treatment. Treat underlying cause where possible. Avoid smoking and pungent foodstuffs. Antiseptic mouthwashes. http://dentalebooks.com Oral and maxillofacial surgery Tissue healing 337 Exodontia 339 Dentoalveolar surgery 344 Biopsy technique 353 Suturing 354 Laser surgery cryosurgery and piezosurgery 355 Infections 356 Swellings of mouth, face and neck 360 Bone pathology 362 Tumours – benign and malignant 363 14 Mouth (oral) cancer 365 Cysts of the jaws 367 Maxillary sinus 369 Pre-prosthetic surgery 373 Implants 375 Maxillofacial trauma 376 The temporomandibular joint (TMJ) 381 Facial and dental asymmetry 383 Orthognathic and cleft surgery 384 Reconstruction 387 Salivary glands 388 Oral Surgery Deals with the treatment and ongoing management of irregularities and pathology of the jaw and mouth that require surgical intervention. This includes the specialty previously called Surgical Dentistry. Oral and Maxillofacial Surgery is a specialty of medicine concerned with the diagnosis and treatment of diseases affecting the mouth, jaws, face and neck, that sits at the interface between dentistry and medicine. Oral and Maxillofacial Surgery specialists are registered on the Register of the General Medical Council but usually have dental and medical qualifications. This reflects that the specialty had its origins in dentistry, but has evolved to formally encompass surgical aspects of care. Tissue healing Surgery by definition results in tissue damage; thus an understanding of factors influencing wound healing is important. Phases of wound healing Inflammatory phase (0–4 days after injury) • The vascular and cellular events in this phase produce a weak repair, which derives most of its strength from fibrin. • Vascular events Initial reflex vasoconstriction; subsequent vasodilation; fibrin and plasma leak into tissues. http://dentalebooks.com 338 • • C L I N I C A L D E N T I S T RY Cellular events Release of lysosomal enzymes from polymorphs; stimulation of macrophage phagocytosis; lymphocytic infiltration. Proliferative phase (3–21 days after injury) At the end of this stage the wound’s strength has increased to 70% that of intact tissue. Fibroblasts produce ground substance and collagen precursors. Together with new capillary buds, fibroblasts form granulation tissue. Remodelling phase (21 days after injury onwards) Contraction of newly-formed scar tissue eventually increases wound strength to 85%. Collagen is initially laid down in a disorganized fashion. Later, remodelling orientates this collagen into a less bulky form. Elastin, however, is not replaced, and thus the scar is less supple. Healing by primary and secondary intention Primary intention Close approximation of wound edges produces a small haematoma. Subsequent granulation tissue and reorganization is therefore minimal. Healing thus results in a narrow scar with good tensile strength – the ideal outcome. Secondary intention Separation of wound edges produces a larger haematoma. This creates a larger volume within which a framework of fibroblasts and capillaries can grow and a greater surface area over which new epithelium must spread. Healing leaves a weaker, more scarred wound, which contracts – a less satisfactory surgical outcome. Bone healing Healing by primary intention. Occurs when there is less than 1 mm separation between bone ends, and rigid fracture fixation. This produces minimal callus. Healing by secondary intention. Results when there is a greater separation of bone ends. Osteoblasts (from periosteum, endosteum and blood) produce larger organizing callus extending between and beyond the ends of the fracture. This is emphasized more if the fixation is not rigid. Extraction socket healing This is an example of secondary intention, combining mucosal and bone healing. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 339 1st week. Inflammatory phase (rubor, tumor, calor, dolor); followed by the start of proliferative phase, with ingrowth of fibroblasts and capillaries; epithelium migrates into the socket to begin covering granulation tissue; bone resorption from socket margins. 2nd week. Osteoid (immature bone, similar to callus) starts being laid down at socket margins; epithelialization usually complete. 4-6 weeks. Lamina dura (the socket wall) resorption usually complete. After 10 weeks. The socket is usually not seen on radiographs; the alveolar process is slowly resorbed. Factors influencing healing Tissue factors. Blood supply (reduced in smoking, diabetes); drainage (may be poor if venous and/or lymphatic outflow is compromised, e.g. previous neck dissection); nutrition (e.g. low protein levels in debilitated patient); previous radiotherapy (poor healing [especially bone] may be due to poor vascularity, cellularity and oxygenation or chronic inflammatory response). Infection. General immune response reduced (older people, immune incompetence (e.g. immunosuppressants, diabetes, HIV/AIDS); local immune response reduced (radiotherapy, topical steroids); adverse physical factors (barriers cut, tissue planes opened, reduced salivary flow); microbes from patient (commensals or infective); microbes from another patient (via instruments/working surfaces); microbes from staff. Operator. Satisfactory healing is influenced by correct diagnosis, planning and execution of surgical procedures (e.g. careful tissue handling, correct design of access flaps, etc.). Exodontia Strength is helpful, but technique is everything! Knowledge of dental anatomy is the key. Valid consent is essential for all surgery. Local anaesthesia (Chapter 9) Adequate local anaesthesia (LA) is essential from the start. Successful LA will be much easier to achieve if the dentist establishes a good rapport with the patient. Reassurance and explanation should include an indication of manoeuvres and pressure that the patient will experience during extraction. Extraction technique The initial movement is a push towards the tooth apex. This should be combined with socket-expanding movements related to the http://dentalebooks.com 340 • C L I N I C A L D E N T I S T RY TABLE 14.1 Extraction technique Tooth Movements (Remember! All these suggested manoeuvres should be used with an apically directed push) Root anatomy Movements Mandibular teeth First and second molar: two flattened roots (mesial and distal); may be divergent or curved Third molars: as above, but roots often joined Lingual and buccal expansion; ‘figure of 8’ movement when tooth mobile; consider elevators for third molar; may take time First and second premolars: single conical root Rotation in horizontal direction Canine: long ovoid root Slow labial and lingual expansion Incisors: slim ovoid root Labial and lingual expansion Maxillary teeth First and second molars: three roots (mesiobuccal, distobuccal and palatal); often divergent Third molars: as above, but roots frequently confluent and fused together Forceps grasp both buccal roots and the palatal; main movement is buccal; ‘figure of 8’ movement when tooth mobile; consider elevators for third molar First premolar: two fine roots easily fractured Second premolar: single oval root (two roots in ~15%) More buccal than palatal expansion – with less force (great care with first premolar) Canine: very long oval root Very slow buccal expansion to avoid fracturing buccal plate; some rotation Cental incisor: single cone-shaped root Lateral incisor: single flattened root Mostly rotation for central incisor Labial expansion for lateral incisor anatomy of the root and socket (Table 14.1). The beaks of the forceps should be pushed carefully under the gingival margin onto the tooth root, not just grasping the crown (Figure 14.1). Be patient with the initial push – it may take considerable time with no apparent progress before the periodontal ligament and socket start ‘giving’. Feel and watch the tooth begin to move and increase expansion movements. Remember that the non-extraction hand should be working just as hard supporting the patient’s maxilla or mandible. In the maxilla this can be achieved by grasping and fixing the maxillary http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 341 'Universal' forceps Molar forceps (mandible) (mandible) 'Universal' forceps (maxilla left/right) Molar forceps (right maxillary) Figure 14.1 Application of extraction forceps. alveolus. In the mandible try to grasp the alveolus between forefinger and thumb and wrap the remaining fingers under the lower border. Having the patient bite on a rubber prop or obtaining an assistant’s help may be advantageous. Elevators can be used to gain initial movements. The movements required for specific teeth are listed in Table 14.1. Complications of exodontia Potential complications of extraction may include: extraction of the wrong tooth (Appendix); failed LA; soft-tissue injuries; nerve injuries (e.g. tongue or lower lip numbness following lower third molar extraction); fractured tooth and failure to retrieve root; fractured buccal plate; fractured maxillary tuberosity; displaced roots (e.g. in maxillary sinus); oral-antral communication; post-extraction haemorrhage; dry socket; infection; precipitation of temporomandibular disorder (TMD); pain – extraction of a painful tooth not providing immediate relief; swelling – particularly following surgical extraction. http://dentalebooks.com 342 • C L I N I C A L D E N T I S T RY Prevention Careful attention to detail can reduce potential complications. Preoperatively Be fully aware of the patient’s medical history, e.g. bleeding tendency, potential drug interactions. Select an appropriate mode of anaesthesia. Consider LA and sedation in anxious patients. Local pathology must be taken into account. A radiograph is always useful. Perioperatively Check the treatment plan to ensure that the correct teeth are extracted – particularly important in extractions for orthodontic purposes (Figure 14.2). Rough or poor technique may cause excessive injury. Pay attention to the outer plate of the alveolus (particularly next to maxillary first molars and canines). If this is moving and attached to the tooth, dissect free from the overlying mucosa before the gingiva is torn. The tooth may remain solid, or movement may be limited. If this happens, do not panic – rest and then expand slowly – consider radiograph. Thorough wound toilet is essential to remove residual debris such as small bony sequestra, carious tooth fragments or restorative materials. Check the tooth after extraction to ensure that the entire root morphology is present. Adequate haemostasis must be achieved. Socket compression between finger and thumb is useful. Biting on a small piece of damp gauze which fits into the edentulous gap helps stem haemorrhage. No patient should be discharged until haemostasis is achieved. If bleeding continues, try to identify specific bleeding point: bleeding that stops upon buccal-lingual finger compression of the socket is of gingival origin and suturing will help – otherwise bleeding is from the bony socket and haemostatic agents (e.g. Surgicel® or Sterispon®) should be packed in the socket. Postoperatively Paracetamol, codeine and/or a non-steroidal anti-inflammatory agent (NSAID) should be commenced immediately following the procedure in order to be effective by the time the LA is wearing off. NSAIDs are less satisfactory since they may interfere with platelet function and haemostasis. Postoperative haemorrhage may be primary (or immediate), reactionary (within 24 hours when reflex spasm of vessels relaxes) or secondary (5–10 days postoperatively – often infective); again, identify bleeding point and suture. Infection may be immediate (i.e. surgery in infected area), intermediate (4–10 days – differential diagnosis dry socket) or chronic http://dentalebooks.com When the instrument is placed on the tooth to be extracted verbal confirmation should be made between surgeon and nurse before extraction continues. Multiple quadrant extractions should be started posteriorly lower right to the midline, then posteriorly upper right to midline then posteriorly lower left to midline then posteriorly upper left to midline (sequence LR,UR, LL, UL) Procedure protocol For the multiple site surgery the grid sheet should be clearly visible for dentist and assistant. This will facilitate confirmation of dental extractions between nurse and surgeon. Nurse/ODP: Has the sterility of the instrumentation been confirmed (including indicator results)? Are there equipment issues or concerns? Anesthetist (for GA or sedation): Are there any patient-specific concerns? What is the patient’s ASA grade? Any special monitoring requirements? Surgeon: Are there any special equipment requirements or special investigations? Are any variations to the standard procedure planned or likely? Have all team members introduced themselves by name and role? Yes Surgeon and Nurse verbally confirm: What is the patient’s name? What procedure, and which teeth? Anticipated variations and critical events Before start of dental surgery TIME OUT (to be read out loud) Sy 8 8 Sy 6 6 E 5 5 E D 4 4 D C 3 3 C B 2 2 B A 1 1 A A 1 1 A B 2 2 B C 3 3 C No/ yes *If the NHS Number is not immediately available, a temporary number should be used until it is PATIENT DETAILS No/ yes weeks Where? Last name: First name: Date of birth: NHS Number*: Procedure: Review Post op care Registered Practitioner verbally confirms with the team: Has the name and site of the procedure been recorded? Has it been confirmed that instruments, swabs and sharps counts are complete (or not applicable)? Have any equipment problems been identified that need to be addressed? Are any variations to standard recovery and discharge protocol planned for this patient? Before any member of the team leaves the surgical room SIGN OUT (to be read out loud) 7 7 Teeth to be extracted /=selected for extraction D 4 4 D E 5 5 E 6 6 7 7 8 8 • This modified checklist must not be used for other surgical procedures. The Operative checklist for Dental extraction ONLY Has the patient confirmed his/her identity, site, procedure and consent? Yes Have you confirmed the teeth to be extracted against the consent form? Yes Is the radiograph present and correctly labeled? Yes Not applicable if digital If multiple quadrant extractions are to be undertaken has the surgeon CLEARLY outlined the extractions on a separate sheet mounted where the surgeon and assistant can see from operating position? Yes Does the patient have a: Known allergy? No Yes Bleeding problem (warfarin, heparin, haemophilia, other)? No Yes, last INR result available Immunocompromised (diabetes, HIV, other) and at risk of infection? No Yes surgeon notified Had prior radiation in the surgical field or previous IV bisphosphonates? No Yes, surgeon notified Has the patient been advised with regard dental restoration if required? Yes Not applicable Before giving local anaesthetic /sedation/general anaesthetic SIGN IN (to be read out loud) Operative checklist for Dental extraction ONLY (adapted from the WHO Surgical Safety Checklist) O ral and m a x illo f acial s u r g ery 343 Figure 14.2 Operative checklist for dental extraction only, adapted from the WHO Surgical Safety Checklist. Courtesy of Professor Tara Renton, King’s College London Dental Institute, London, UK. (consider retained root fragment or other pathology [question original diagnosis]). Dry socket (focal alveolar osteitis) Incidence. Incidence is about 2% of extractions. More common in mandibular than maxillary extraction sites. Also more common following surgical removal of teeth, e.g. lower third molars. http://dentalebooks.com 344 • C L I N I C A L D E N T I S T RY Aetiology. The aetiology of dry socket is uncertain. Infection is probably not the primary cause (although some trials show reduced incidence of dry socket when antimicrobials are used). Some studies have shown excessive fibrinolytic activity; this may lead to premature loss of clot. Impaired vascular supply to the socket wall has been implicated. Smoking, the use of oral contraceptives and immune defects increase the incidence. Diagnosis. Pain (or burning sensation) occurs 24–48 hours postextraction, frequently with noticeable odour and bad taste. The alveolar socket wall is often exquisitely tender. Blood clot may be lost from the socket, but there is often little evidence of clinical infection. Treatment. Under LA irrigate and look for debris and sequestra. Apply warm sterile saline (salt water) by irrigation regularly to the socket. A pack impregnated with a eugenol- or iodophor-based obtundent may be helpful if these more simple measures are unsuccessful. Such packing may retard long-term healing and so should be removed at the review appointment. Dentoalveolar surgery Surgical removal of teeth Extractions may become problematic when a portion of root or tooth cannot be removed from the alveolus. In this case, it may be necessary to cut the tooth and/or alveolar bone, to enable the remaining fragment to be removed (see also coronectomy, p. 349). Stages in the surgical extraction of the mandibular right first molar are illustrated in Figure 14.3. Usually, a mucoperiosteal flap (1) must first be raised, as the roots (2) are usually beneath bone margins. Bone is thus exposed (3) and can be removed from the area around the root (4) with a bur. Bone should be removed initially from the coronal aspect of the root to try to create a point of application for an elevator (5). (Numbers refer to Figure 14.3.) On occasion it is possible to elevate roots without raising a flap; e.g. a very broken down crown which can be removed piecemeal on a molar tooth. This allows sectioning of the remaining stump with a bur into individual roots, which can then be elevated separately. Principles of flap design When raising a mucoperiosteal flap, careful consideration must be given to the following to ensure viability postoperatively and promote satisfactory wound healing: • the base of the flap should be broader than its tip to provide an adequate blood supply http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 345 5 4 5 1 4 3 3 Mental nerve 2 1 2 3 4 Relieving incision angled forward Buccal mucoperiosteal flap Retained root mandibular first molar Lateral plate of mandibular alveolus Initial area of bone removal in a ‘trench’ around retained root 5 Example of a ‘point of application’ for elevator application Figure 14.3 Third molar surgical extraction; stages in the surgical removal of the right first mandibular molar. • • • • relieving incisions should not be made at acute angles tissues should be handled with due care and attention the design should enable sufficient access for surgery postoperatively, the flap margins should rest on sound bone. Inexperienced operators frequently raise too small a flap. ‘Keyhole’ surgery should be avoided. It is important to be aware of underlying anatomical structures as potential hazards when making an incision. In particular: mandibular 4, 5 region buccally – mental nerve; mandibular 8 region lingually – lingual nerve; maxillary 7, 8 region buccally – pterygoid plexus; palate – long palatine and nasopalatine artery. Elevators These instruments are used to prise out teeth and pieces of root, which cannot be grasped by forceps, or to facilitate forceps application (Figure 14.4). The elevator point must engage the side of the root surface (usually within the periodontal ligament) and have a fulcrum point (usually alveolar bone). This combination is called the point of application and is the secret to successful elevation. There are two types of elevator. The more common type is oval in cross-section, e.g. straight Warwick James’. It is this cross-sectional http://dentalebooks.com 346 • C L I N I C A L D E N T I S T RY Coupland’s elevator Warwick James’ elevators Figure 14.4 Commonly used elevators; Coupland’s and Warwick James’ elevators. asymmetry that holds the key to its mode of action. The elevator point is maintained in contact with the root surface, and as the oval shaft is rotated against the inner rim of the alveolar margin, the root is rotated free. The curved Warwick James’ is an example of the hooked type of elevator. Again, the tip of the instrument is applied to the root surface and the root is literally ‘hooked’ out of the socket, using the alveolar margin as a fulcrum. When elevating teeth remember: support the jaw with your other hand; sufficient bone often needs to be removed to allow the elevator a point of application and to allow the root a path of removal; consider the curvature of the root as this will dictate the path of root removal; the angle of approach of the elevator is crucial to enable the point to grip the tooth and the shank to have a fulcrum point on the bone; the elevator is a sharp-ended instrument. Use it with care http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 347 (avoid excessive axial pressure, which may lead to lingual displacement and injury). A finger rest is recommended. Carefully observe the tooth. Is the root moving as expected? Bone removal When surgically removing teeth, sufficient bone should be removed to create an application point on the tooth root. Bone may be removed using either a handpiece and bur or chisels. The latter are used only when operating under GA in young patients (bone is less brittle). Care should be taken not to damage the roots of adjacent teeth or important anatomical structures. A sterile saline spray should be directed on the bur at all times to avoid overheating the bone. All bone fragments should be carefully removed to prevent postoperative infection. This is aided by efficient irrigation and aspiration. Remove only sufficient bone to ensure adequate access to the tooth root. Impacted third molars Indications for removal Pericoronitis. Recurrent inflammation/infection of the overlying operculum associated with partially erupted third molars. Surgery should be delayed until the acute phase has been treated. Caries. Associated with a stagnation area; may result in caries in the third molar or distal aspect of the second molar. Orthodontic. Association with crowding is not proven; however, removal may be necessary for appliance therapy and orthognathic surgery. Associated pathology. e.g. a dentigerous cyst (i.e. cyst around unerupted tooth crown). Symptoms arising from partly erupted third molars may be vague and every effort should be made to make a correct diagnosis. Symptoms of TMD (e.g. myofascial pain) are often erroneously attributed to impacted third molars. Beware of ascribing pain to buried teeth, particularly those which are covered completely with bone and discovered only on a radiograph. There is controversy surrounding the removal of asymptomatic impacted third molars. Provided there is no communication between the tooth and the oral cavity, studies suggest the likelihood of problems if the tooth is left in situ, is small. Guidance on the removal of third molars has been issued in the UK by the National Institute for Health and Clinical Excellence (NICE) and the Scottish Intercollegiate Guidelines Network (SIGN). However, these have been challenged and a review of the current guidelines by NICE is expected. More information on the guidelines is available from: http://www .nice.org.uk/guidance/ta1/history. http://dentalebooks.com 348 • C L I N I C A L D E N T I S T RY Radiographs in third molar diagnosis Careful radiographic examination should be undertaken in the assessment of third molars. A panoral view may be sufficient; intraoral views may be added to delineate further detail, e.g. caries or inferior dental nerve proximity. Note the following: Position Angulation of the tooth relative to the occlusal plane, e.g. vertical, mesioangular, distoangular, horizontal, ectopic (grossly displaced). Depth of impaction. The relation of the maximum convexity of the most inferior part of the tooth crown to the margin of the alveolar bone. Tooth morphology. Crown size/shape and presence of caries. Root morphology. May be favourable (conical), or unfavourable (bulbous or hooked tip). Surrounding structures. Inferior alveolar canal. Position relative to tooth apices. In particular look for: darkening of root (as it crosses the canal); deflected roots (away from canal); loss of continuity of canal roof (white line). If in doubt, consider a Cone Beam CT (CBCT). Trabeculation of bone. Whether surrounding bone is sclerotic, normal or rarefied in type. Pathology. e.g. cyst, caries. Other structures. e.g. morphology of second molar (conical roots, so easily loosened), and presence of crown or distal amalgam that could be damaged. Access. Usually determined clinically (remember to assess aspects such as degree of opening possible); however, the radiograph may help by estimating the distance between the distal aspect of the second molar and the anterior border of the ramus of the mandible. Removal of impacted third molar Elevation of a buccal flap. (Figure 14.5) The usual approach is via a buccal mucoperiosteal flap around the crown of the partially erupted 8. The gingival papilla between the 7 and 8 is included in the flap. From the gingival papilla, a relieving incision is continued down the side of the buccal alveolus (Figure 14.5i). For the distal part of the incision, it is important to have an understanding of the anatomy of the area immediately posterior to 8. If an incision were to be made directly posterior to 8, and in line with the alveolus, it would inevitably end up in the lingual sulcus, where the lingual nerve is vulnerable to damage. Thus the posterior incision should be angled laterally up the external oblique ridge (this is easily http://dentalebooks.com O ral and m a x illo f acial s u r g ery (i) 349 Inferior dental nerve Lingual nerve Lateral oblique ridge 'Overhang' of posterior mandibular alveolus Outline of flap (ii) • Bur cuts enable space to be created to elevate roots separately Path of removal Figure 14.5 Removal of impacted third molar. palpable and more lateral than you might think). The buccal flap may now be lifted to facilitate access to the impacted tooth. Difficulty is often encountered around the partially erupted crown where the mucoperiosteum is adherent. Elevation of a lingual flap. The incision described above also allows a lingual flap to be raised. Some think this is of importance in preventing lingual nerve injury. Others argue that less injury occurs without elevating this flap, and there is evidence that for nonspecialist operators this may be the best for more simple surgical procedures. To raise a lingual flap it is most important to remain in the subperiosteal layer. This requires care as the alveolus overhangs the mandibular body on its lingual aspect, and there is a considerable concavity to deal with. If the periosteal elevator should pass through the periosteum by accident, and is then held as a retractor, the nerve may be trapped on the wrong side of the elevator (between the elevator and bone) and thereby become damaged. http://dentalebooks.com 350 • C L I N I C A L D E N T I S T RY Surgical removal. (Figure 14.5ii) Sufficient bone should be removed to allow visualization of the impacted tooth. The tooth itself is then sectioned so that it can be removed piecemeal. A tungsten carbide bur is used to cut as well as create a space to remove pieces separately. As with most practical procedures three-dimensional perception (particularly the location of the bur tip) is the key to preventing unwanted damage. Nerve damage. Nerve damage to inferior dental nerve and lingual nerve are potentially serious long-term complications of surgical third molar removal. This can be limited by adequate preoperative assessment and careful surgical technique. Coronectomy, a technique where only the crown of the tooth is removed leaving the root behind, is supported by some, as an alternative to the full surgical removal, mainly in cases of deeply impacted teeth where the risk of inferior alveolar nerve damage is high. All patients should, as part of the consent process, be warned about the possibility of pain, nerve damage and of postoperative swelling and trismus. Document in case notes. Closure. Whilst sutures may contribute to postoperative dis­ comfort, their placement is usually required to achieve satisfactory wound closure, haemostasis and an adequate gingival contour postoperatively. Postoperative care. Advice on a suitable analgesic (e.g. paracetamol and/or ibuprofen) should be provided to be commenced before the LA wears off (consider the use of a long-acting LA such as bupivacaine). Some advocate the use of chlorhexidine mouthwash, commencing 24 hours after extraction. The prescription of antibiotics following third molar extraction is not supported by evidence, but should be considered where extraction involves significant bone removal or chronic infection is evident, or if the patient is immunocompromised. Patients should always be provided with an information sheet and details of how to access care, should an emergency arise postoperatively. Maxillary canine exposure/removal Assessment This is usually done in conjunction with an orthodontist. History. Including planned orthodontics. Examination. Palpate to determine whether the crown is obvious palatally or labially. Note displacement of other teeth – tipping of the http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 351 lateral incisor crown palatally usually indicates a palatal impaction of the canine. Radiography. Two intraoral views are usually required to permit parallax assessment (an anterior occlusal and one intraoral will also suffice). If the crown moves with the tube it lies palatal. Take care to notice if the canine lies across the arch of the alveolus (e.g. crown labial, root apex palatal). A panoral film can be useful. For estimation of the depth that the canine is in bone, a lateral cephalogram may help. Resorbed roots, particularly of lateral incisor, should be assessed and noted, as should the presence of cystic change around the crown. Treatment Frequently requires day-case GA. Palatal flap. Around the necks of the standing teeth. This should start at the first maxillary molar and travel to the opposite canine (or molar if both canines involved). Labial flap. Around the neck of the lateral incisor, canine and first premolar, with a relief incision, is used for labially positioned canines (less common). Canine exposure. For palatally placed teeth a flap is not necessary. An area of mucoperiosteum directly overlying the crown is excised with a monopolar electrosurgical device (open exposure) and bone is removed with great care to avoid damaging the crown or junction with the root (avoid the use of burs – a small chisel or Mitchell trimmer is preferable). The whole of the greatest curvature of the crown is exposed and a suitable pack is placed – a dressing plate fabricated preoperatively is useful to carry a periodontal dressing (e.g. Coe-pak) in the area of the exposed tooth. Labially placed teeth are probably best treated by bracket attachment with a gold chain leading out to the mouth and the flap sutured back in place (avoiding an apically repositioned flap – closed exposure). Surgical removal. Usually necessitates bone removal and may require crown section with elevation in segments. Palatal impactions may be quite difficult, and correct patient positioning (head extension) is critical. Care must be taken not to damage neighbouring teeth, e.g. with burs or elevators. Apicectomy (Apical end or root end surgery: Chapter 19) Apicectomy Surgical removal of the root apex, to allow the operator to visualize and gain access to the root canal. The main aim of the procedure is to establish an apical seal. http://dentalebooks.com 352 • C L I N I C A L D E N T I S T RY Indications for apicectomy • Failure of conventional endodontic therapy to eliminate apical infection • Pathological change at the apex of a previously root-filled tooth, e.g. granuloma or cyst • Failure during root canal treatment, e.g. overfilling, instrument fracture, lateral perforation • Root unapproachable by conventional orthograde route, e.g. postcrowned tooth, calcified root canal • Anatomical variations preclude normal endodontic therapy. Apicectomy alone cannot address the problems in complete root canal preparation and obliteration. Technique (see Figure 14.6) 1. Access flap A mucoperiosteal flap is raised. A triangular flap is preferred, and careful repositioning and suturing minimize postoperative recession. 2. Apical curettage A bony window is opened with a bur (unless already present due to pathology). Any apical cystic tissue, granulation tissue or infection resulting from failed root canal therapy should be curetted and sent for histological assessment. 3. Apicectomy Section of the root apex with a slight anterior bevel to facilitate visualization of the root canal. It is important to maintain as much of the root length as possible, while removing the apical portion with the most potential for lateral canals and allowing access for curettage of the bone cavity behind the apex. 4. Retrograde root filling Where the apical seal is deficient, the root canal is cleaned out of old root filling and infected and necrotic dentine using an ultrasonic source and microtip. This enables the remaining apical root canal to be prepared without unnecessary loss of root or inadvertent perforation. The use of magnifying loupes is advantageous. A suitable cement, e.g. EBA (orthoethoxy benzoic acid) or MTA (Mineral Trioxide Aggregate), is now used as a filling material. This should be a thick mix, well compressed by suitable instrumentation. Special micro-instruments are available to facilitate this. Formerly, amalgam was used, so it is not uncommon to see patients with amalgam tattoos high in the sulcus. Even with the best retrograde root filling, the whole of the root canal is not prepared and sealed. Difficult cases are best approached from both ends, completely dismantling the restorative crown and post if this is technically possible. This allows an orthograde/ retrograde approach. The canal is overfilled using gutta-percha and cement in an orthograde direction. This filling then protrudes at the root end and can be cut back under direct vision. Best treatment is always a well-placed orthograde root filling. Many of the ‘indications’ for apicectomy may be solved by a skilled endodontic practitioner with an orthograde approach alone (Chapter 19). http://dentalebooks.com O ral and m a x illo f acial s u r g ery 2 Curettage of apical pathology • 353 3 Apex removed with any lateral canals 4 BevelIed end Cavity preparation 1 Gingival margin flap: (relief only anteriorly) 1 Access flap 2 Apical curettage 3 Apicectomy 4 Retrograde root filling Figure 14.6 Apicectomy of maxillary right lateral incisor. Biopsy technique Biopsy involves excision of tissue for histological examination. Where the lesion is extensive, consideration should be given to sampling from more than one site. Excisional biopsy. The lesion is excised in its entirety with a small margin of healthy tissue surrounding it. Incisional biopsy. Removal of a representative portion of the lesion; should try to contain clinically healthy tissue at the margin. In potentially malignant lesions, the area most likely to show significant dysplasia should be included in the biopsy, e.g.erythroplasia or the red part in a non-homogeneous speckled leukoplakia. If cancer is suspected, the biopsy should be deep enough to allow histological assessment of the invasive front. Punch biopsy. has gained favour with clinicians and patients alike. Technique. Try to infiltrate LA around the site, not directly into it. A suture placed through the tissue to be excised is preferable to grasping with forceps as this prevents crushing the sample. This also helps orient the specimen for the pathologist. An elliptical biopsy of the edge of a lesion should result in easy wound closure with two or three sutures. http://dentalebooks.com 354 • C L I N I C A L D E N T I S T RY Full clinical details of the patient along with a differential diagnosis should be entered on the request form sent to the pathologist. Good communication with the pathologist is important in arriving at an accurate diagnosis. Remember, the pathologist can only report on the tissue received, so it must include the pathological areas of concern. Suturing Sutures are used to hold flaps and tissue in apposition to facilitate wound healing. Suture materials Resorbable. Polyglycolic acid (e.g. Vicryl) is used for suturing within tissue layers (buried). Most surgeons use these routinely for surface oral mucosa as their use avoids the need for suture removal. Non-resorbable. Fine nylon or other monofilament suture is used for skin. Needles May be cutting (for skin and attached gingival) for ease in passing through tissue or round bodied (for mucosa) – avoids cutting out of tissue as the needle is passed through. Suture techniques There are a variety of suture techniques possible, e.g. interrupted, vertical mattress, horizontal mattress, continuous. Interrupted suture. The suture should be passed from the free flap into the fixed tissue. The free edge of the flap is supported by toothed dissecting forceps; the needle is held in needle holders and inserted about 3 mm from the wound edge following the line of the needle curve. The needle is grasped as it emerges from the deep aspect of the flap and inserted in the underside of the opposing wound margin. It should be angled so that the needle emerges about 3 mm from the wound edge. The two ends of the suture are knotted so as to maintain the wound edges neatly in apposition. The standard knot tied with needle holders has two forward loops which are tightened and one loop turned back which is tightened. A further single loop may be necessary for added security. Avoid causing over-tension – tissues should not be blanched. Suture removal. Non-resorbable sutures are normally removed 5–7 days postoperatively. The tied ends of the suture are grasped in nontoothed forceps and fine point scissors or a stitch cutter is inserted http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 355 under the knot and one side of the suture is cut. By gently pulling with the forceps the suture is removed. Any adherent debris may be removed with chlorhexidine solution before the suture is removed. Laser surgery, cryosurgery and piezosurgery Laser surgery LASER stands for Light Amplification by the Stimulated Emission of Radiation. As the energy emitted can be carefully controlled, lasers may be used to destroy or cut through or damage soft tissue. Laser types include: Cutting lasers • Carbon dioxide; neodymium:YAG (yttrium–aluminium–garnet) Non-cutting lasers • Argon laser; tunable dye laser; copper laser. These are well absorbed by pigmented substances and can be used selectively to destroy superficial vascular anomalies, sensitized tumours (tumour cells are identified by antibodies with pigment attached), tattoos and hair, at the same time sparing surrounding normal tissues. Carbon dioxide (CO2) laser This is the main laser used in surgery; the light emitted from it is well absorbed by water, e.g. in soft tissue. The major intraoral application is the excision or ablation of potentially malignant lesions (dysplasias). Excision of soft tissue neoplasms is also possible with more powerful models. The depth of destruction can be controlled precisely, and small blood and lymphatic vessels are sealed. The wound produced by a CO2 laser is said to heal with less scarring than other wounds. Fewer myofibrils are generated in healing. This, together with retention of the connective tissue skeleton, reduces scar contraction. Carbon dioxide laser surgery may also be associated with less postoperative pain. However, assessment of laser excision margins may be difficult. Cryosurgery This involves the controlled destruction of tissues by freezing. Liquid nitrogen, carbon dioxide and nitrous oxide take in energy from their surroundings when they vaporize or expand. Formation of intra- and extracellular ice crystals leads to disturbances in osmotic and electrolyte balance and results in cell death at −20°C or below. Clinical http://dentalebooks.com 356 • C L I N I C A L D E N T I S T RY cryosurgery may involve, for example, a 30 second freeze and 30 second thaw in two or three cycles. Postoperatively, there is often a degree of swelling in soft tissue areas to which the cryosurgery has been applied. Cryosurgery does not give an opportunity for biopsy. There is a lack of scarring, probably related to the preservation of the connective tissue skeleton. Applications include cryoanalgesia and cryoneurectomy for trigeminal neuralgia (e.g. of the mental nerve). It has also been used in the treatment of soft tissue lesions, e.g. haemangioma, and some intrabony lesions. Piezosurgery Ultrasound is sound energy with a frequency above the range of human hearing, which is 20 kHz. For clinical purposes, ultrasound is generated by transducers, which convert electrical energy into ultrasonic waves achieved either by magnetostriction or piezoelectricity. Piezosurgery is an osteotomy technique utilizing microvibrations at ultrasonic frequency to perform efficient bone cutting – increasingly used in oral surgery. Selective cutting is the most innovative feature of piezoelectric surgery as it cuts mineralized tissues such as bone, but does not cut soft tissues such as blood vessels, nerves, and mucosa. Infections Infection of dental origin Infections that are dental in origin frequently have a mixed bacterial (polymicrobial) aetiology, e.g. streptococci (usually aerobic) and Bacteroides (anaerobic). Bacteroides species are anaerobic bacteria that are predominant components of the florae of mucous membranes and are therefore a common cause of endogenous infections. Bacteroides infections can develop in all body sites, including the mouth and peri-oral regions, head, the neck, CNS, the chest, the abdomen, the pelvis, the skin, and the soft tissues. Because of their fastidiousness, Bacteroides are difficult to isolate and thus often overlooked. Their isolation requires appropriate methods of collection, transportation, and cultivation of specimens. Treatment is complicated by slow growth, increasing resistance to antimicrobial agents, and the polymicrobial synergistic nature of infections. Localized infections The majority of dental infections remain localized. Apical (dental) abscess. The most common type of abscess arises from an infected non-vital pulp chamber. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 357 Periodontal abscess. An infection within a periodontal pocket (Chapter 17). Pericoronitis. Pericoronitis is defined as infection of the operculum (i.e. the mucosa that covers a partially erupted tooth). Primary treatment is by irrigation under the operculum with chlorhexidine solution (0.2%). It is usually necessary to remove the partially erupted third molar (or the maxillary third molar to reduce occlusal trauma). Systemic antibiotics should be considered if there is evidence of trismus, lymphadenopathy or spreading infection. Spreading infection Whilst most infections remain localized, an infection may spread. Pus from an infected tooth will spread along the path of least resistance. This may present as an extra- or intraoral swelling or sinus, but can on occasion spread along tissue and fascial planes to produce severe, life-threatening infections. The pattern of spread associated with specific teeth often follows a distinct path, as indicated in Table 14.2 and Figure 14.7. TABLE 14.2 Patterns of spread of odontogenic abscesses Tooth Potential spread Maxillary teeth Molars and premolars Swelling or sinus in buccal sulcus may spread to buccal space (lateral to buccinator) Canine Canine fossa – nasolabial fold area, spreading from lower eyelid to buccal space Lateral incisor May track to palate due to distal inclination of root, but usually labial Central incisor Labially – can give a swollen lip Mandibular teeth Third molar (Beware! pericoronitis may track buccally along the inner aspect of buccinator to present in 5,6 region) Has the potential to spread in many directions: submasseteric space, submandibular space via lingual plate, pterygomandibular space, lateral pharyngeal space and on down the neck Second molar (the commonest culprit of severe fascial space and lifethreatening neck infections) Often spreading lingually – can lead to severe sublingual, submandibular, pterygomandibular and spreading neck infections First molar Usually buccally, with vestibular or buccal abscess Premolars and canine Buccally Incisors Labially – may spread to submental region http://dentalebooks.com 358 • C L I N I C A L D E N T I S T RY Tongue 5 1 1 6 2 2 4 8 3 7 1 Sublingual space 5 Mandible 2 Submandibular space 6 Mylohyoid muscle 3 Submandibular salivary 7 Platysma muscle gland 8 Deep cervical fascia 4 Hyoid bone Cross-section mandibular region premolar area Skull Pterygoid plates 2 8 1 6 Soft palate Tongue 7 Zygoma 4 3 Masseter 5 Mandible Mylohyoid muscle Hyoid Submandibular space Submandibular salivary gland 1 Superficial temporal 5 Lateral pharyngeal space space 2 Infratemporal space 6 Lateral pterygoid muscle 3 Masseteric space 7 Medial pterygoid muscle 4 Pterygomandibular 8 Temporalis muscle space Cross-section mandibular ramus region Figure 14.7 Potential spaces in spreading dental infections. In all these spreading infections be alert to systemic conditions underlying the acute spread, e.g. diabetes, or other immune deficiency. Other infections of the head and neck region Patients with these infections invariably need urgent hospital care. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 359 Facial cellulitis. This may be of any origin including odontogenic and presents with diffuse inflammation throughout subcutaneous tissues and deeper tissues. On examination, the skin feels firm with no fluctuance. Onset may be rapid, and there is no pus initially. Treatment is by surgical eradication of infected focus supplemented by systemic antibiotics. Careful observation is necessary, as abscess formation may occur, and this requires surgical drainage. Osteomyelitis. An acute or chronic infection of bone. Most commonly, both forms are associated with odontogenic infection and usually another factor promoting spread (e.g. immunosuppression). Ludwig’s angina. This is a cellulitis (not abscess) involving floor of mouth (sublingual) and bilateral submandibular spaces, which can quickly extend into the neck (deep cervical fascia, parapharyngeal space) and then the mediastinum. Tongue and floor of mouth are elevated. As it tracks down the pharynx ‘hot potato speech’ may develop. The real danger signs are difficulty swallowing and speech problems. Prompt referral and treatment is crucial as the airway can become compromised rapidly. Appropriate assessment of the airway by an anaesthetist, antibiotic therapy and prompt surgical intervention have dramatically improved the prognosis of this once lethal condition. Necrotizing fasciitis. This is rare in the head and neck. It is characterized by a rapidly progressive necrosis of fascia, subcutaneous fat and muscles, that undermines and eventually causes necrosis of overlying skin. Cavernous sinus thrombosis. Veins in the facial region communicate with the cranial cavity, and, very rarely, infection may backtrack from the mid-face up into the skull to the cavernous sinus. Cancrum oris/noma. This is associated with malnutrition (immunosuppression), and fuso-spirochaetal organisms similar to those associated with acute necrotizing ulcerative gingivitis are implicated in this condition. Infection of non-dental origin Any of the spreading infections above may originate from nonodontogenic sources, including: Salivary gland. Chronic ascending suppurative parotitis. Skin. Infected sebaceous cyst; furuncle (suppurative folliculitis); impetigo. Bone. Acute or chronic osteomyelitis. Other. e.g. sinusitis, tonsilitis. http://dentalebooks.com 360 • C L I N I C A L D E N T I S T RY Patient assessment in infection The factors identified in Chapter 7 relating to diagnosis apply equally to a patient with an infection. However, the following specific features should also be recorded: History. Speed of onset; malaise; rigors; effect on breathing and swallowing; medical factors, e.g. drugs, diabetes. Examination. Temperature; heart rate; respiratory rate; trismus; lymphadenopathy; spread, e.g. floor of mouth, tongue elevation, neck involvement, airway/voice. Delineate extent of swelling as a baseline. Microbiology. Aspirate pus with a needle for an uncontaminated sample – also helps preserve anaerobes; a pus specimen in a sterile pot is better than a swab in transport medium; involve the bacteriologist early if there is serious infection. Other tests. include radiography, vitality tests, blood tests (white cell count, glucose). Differential diagnosis Differential diagnosis is particularly important. If temperature is elevated postoperatively, consider: atelectasis and lung infection, infection at the surgical site, urinary tract infection, deep vein thrombosis (DVT), infection at site of an indwelling line (intravascular catheter; see Figure 14.8). Management. The basic principles in managing a patient with infection involve: accurate diagnosis; incision and drainage; attention to the primary focus; appropriate antibiotic therapy. Swellings of mouth, face and neck A vast range of pathologies can present as a swelling. It is essential to be able to identify efficiently the possible cause of swellings. History. Record as described in Chapter 7. In particular note: duration; variation in size; pain – its nature and radiation; any neurological involvement. Examination. Describe as follows: Look. Site; size; shape; surface (e.g. ulcerated); colour. Feel. Consistency (e.g. fluid-filled, soft, firm, hard); relations (e.g. attachment to or displacement of other surrounding structures). Assess sensory changes (e.g. mental or infra-orbital nerve). Transillumination. If cystic, or to determine if a hollow structure is filled, e.g. maxillary sinus. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 361 Intracranial pressure monitor Nasogastric feeding tube Ventilation via tracheostomy Ventilation via a nasotracheal tube Ventilation via an orotracheal tube Subclavian venous line ECG line Ventilation of lungs via nose/mouth/ tracheostomy to support breathing ECG line Venous lines via peripheral or central access to measure pressure in the heart and lungs centrally, or sample blood and give drugs and blood or blood products Intravenous line Chest drain ECG line Gastrostomy feeding tube Pulse oximeter Intra-arterial line Urinary catheter Antithrombotic stockings Feeding tubes via nose and oesophagus or direct into stomach (central feeding) Despite all the high-tech instrumentation, the most important recordings are: ¥ Pulse rate and peripheral perfusion ¥ BP ¥ Respiratory rate ¥ Urinary output/hour Figure 14.8 Patient following major trauma/surgery/infection. Auscultation. If a vascular anomaly is suspected, a bruit (flow murmur) may be heard. Examine lymph nodes. Lymphadenopathy is the most common cause of swellings in the neck. Examination of the lymph glands should be conducted in a systematic fashion using gentle palpation. Relax the patient, gently tilt the head forward and towards the side being examined. Start in the submental/submandibular area, standing behind the patient. Palpate around the angle of the jaw and up around the base of skull. Then work down around sternocleidomastoid (anterior and posterior to the muscle). Special tests Vitality tests. of surrounding teeth to elicit a possible dental cause. http://dentalebooks.com 362 • C L I N I C A L D E N T I S T RY Ultrasound (US) examination. may aid diagnosis by, for example, revealing whether the swelling is fluid-filled. Radiography. Computed tomography (CT) scanning and magnetic resonance imaging (MRI) may provide valuable information (Chapter 8). Fine needle aspiration (FNA). is mandatory for neck lumps where the diagnosis is uncertain. FNA may be US-guided (US-FNA). Remember – common things occur commonly. Always list the possible diagnoses with the most likely first. To avoid missing possible diagnoses, think of what structures are contained in that anatomical area. Differential diagnosis A useful method of arriving at a differential diagnosis of a lump of unknown origin is by use of a ‘surgical sieve’, based on possible aetiological factors. Developmental. e.g. torus mandibularis or palatinus, haemangioma, lymphangioma, branchial cyst. Inflammatory. (e.g. orofacial granulomatosis, angio-oedema) or Infective. The most common cause of lumps and swellings in the head and neck region. Neoplastic Traumatic. Common examples include oedema and haematoma following operation or accident, fibroepithelial polyp, denture hyperplasia, mucocele. Endocrine. e.g. thyroid disease. Bone pathology Fibrous dysplasia Paget’s disease of bone Osteopetrosis Osteogenesis imperfecta Hyperparathyroidism. Displays focal bone ‘brown tumours.’ Ossifying fibroma. The aetiology of this condition is uncertain. It may be a localized disorder of bone metabolism or a benign tumour. Often the only real difference between this swelling and fibrous dysplasia is the fibroma’s discrete mass (clinically and on radiograph) http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 363 and the relatively clear separation on surgical removal. Treatment is similar to that of fibrous dysplasia, but because of its discrete morphology, ossifying fibroma is more often removed in its entirety. Giant cell lesions. Describe a number of conditions with a common feature of giant cells seen on histology. Peripheral giant cell granuloma (giant cell epulis). Possibly related to trauma and usually responds to curettage. Central giant cell granuloma. Can be aggressively destructive – but benign. May recur after curettage. Radiographs often show multilocular radiolucency. Brown tumour of hyperparathyroidism. Cherubism. Autosomal dominant inherited, resulting in bone remodelling in mandible and maxilla. Aneurysmal bone cyst. Demonstrates haemorrhagic and cystic areas on histology. Tumours – benign and malignant Due to the large variation in presentation of growths in the head and neck region, categorization is complex. The following is a basic classification of growths and tumours. Hamartomas These arise before or soon after birth and grow with the patient; the swelling stops growing with the patient so they are not classified as tumours. Common examples include: Pigmented naevi (moles). A collection of melanocytes. Vascular malformations. A collection of blood or lymph vessels. Odontomes. Differentiated as compound odontomes – normal relationship of enamel, dentine, cementum; and complex odontomes – diffuse masses of abnormal tooth tissue. Exostoses. e.g. tori. Neoplasms Neoplasms may be differentiated into benign and malignant varieties (Table 14.3). A neoplasm (often called tumour) is an abnormal mass of tissue whose growth exceeds and is uncoordinated with that of surrounding tissues. Abnormal growth continues after the stimulation which initiated it has ceased. http://dentalebooks.com 364 • C L I N I C A L D E N T I S T RY TABLE 14.3 Characteristic features of benign and malignant tumours Benign tumours Malignant tumours Slow growing (usually) Fast growing (often) Well differentiated Poorly differentiated Infrequent mitoses High mitotic rate Little cytological variation Nuclear and cellular pleomorphism; abnormal mitoses Encapsulated; remain localized Local spread and distant metastasis Benign neoplasms Benign tumours remain at their site of origin. Common examples include: Lipoma. (fat). Neuroma. (nerve). Papilloma. (epithelium). Locally invasive neoplasms As in benign tumours, growth is abnormal. There is, in addition, invasion into surrounding normal tissues. Examples include: Ameloblastoma. (enamel-producing organ). Basal cell carcinoma (BCC). (skin), sometimes called ‘rodent ulcer’. Keratocystic odontogenic tumour (KCOT). (jaw cyst). Malignant neoplasms In malignant tumours there is abnormal growth with the potential for local invasion and distant metastases. The latter may be via blood, lymphatics or body cavities. Carcinomas are malignant tumours of epithelial tissue. The most common malignant tumour in the oral cavity is the squamous cell carcinoma. Sarcomas are malignant tumours of connective tissue, e.g. liposarcoma, osteosarcoma. Odontogenic neoplasms These are rare (some very rare). The majority are benign (some are more hamartomatous than tumours). Only a few are locally aggressive, and they do not usually metastasize. However, they should not be underestimated, as local spread to the skull base may kill. Epithelial odontogenic tumours Ameloblastoma. The mean age of occurrence for this tumour is about 40 years, although they can arise at any age. They are most http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 365 commonly found in the mandibular body/ramus region. They are locally invasive; this is particularly important in the posterior maxilla. Ameloblastoma normally presents as an expanded lesion of bone, which is seen radiographically as a multilocular radiolucent area (see Chapter 8, Table 8.16 for differential diagnosis of mutilocular radiolucencies). Treatment is by surgical resection of the tumour, taking a clear margin to ensure its eradication. Calcifying epithelial odontogenic tumour. This is clinically and radiographically similar to ameloblastoma, and is often associated with an unerupted tooth. It may also contain radio-opaque areas. Treatment is by surgical removal. Mesenchymal odontogenic tumours Odontogenic myxoma. Equally distributed between maxilla and mandible; most common at around 30 years of age. Usually presents as multilocular radiolucency. Treatment is by surgical excision of the tumour and a small margin of surrounding tissue. Cementifying fibroma. Indistinguishable from ossifying fibroma. Mixed odontogenic tumours Odontomas (odontomes). Really hamartomas. Ameloblastic fibroma. (including fibro-odontoma). Most common in young adults in the mandibular body/ramus region. Radiographs show a radiolucent lesion (often with a calcified area), which may be associated with an unerupted tooth crown. Treatment is by curettage. Mouth (oral) cancer The epidemiology and aetiology of squamous cell carcinoma (SCC) are discussed on p. 312 in Chapter 13. Assessment In addition to the usual features in examination and diagnosis (Chapter 7), particular note should be made of: History. Duration of symptoms; any sensory nerve deficit; pain; onset of difficulty opening mouth (trismus); social habits and circumstances; problems with eating. Examination. This should include an exhaustive description of the primary lesion, which may be on an ulcer: size; shape; colour; description of the ulcer edge; degree of induration (hardness); whether bound down to other tissues; which tissues are involved clinically with the mass. http://dentalebooks.com 366 • C L I N I C A L D E N T I S T RY It may be useful to assess movement restriction, e.g. of the tongue, or the ability to open the mouth – remember this may be tumour invading muscle or motor nerve supply. Sensory function (e.g. mental, lingual and infraorbital nerves) needs to be checked and the neck examined for lymph node involvement. Finally, the nutritional status of the patient must be assessed. Special tests. The following special tests may be indicated in further assessment: Blood tests. In particular, full blood count (haemoglobin levels and nutritional status) and liver function tests (estimation of associated alcohol damage). Imaging. Orthopantomogram; CT and/or MRI of the mouth and neck; CT of the chest and abdomen. Biopsy Examination under anaesthesia (EUA). Often enables the best assessment of more posterior or painful lesions and enables endoscopy for other (synchronous) lesions (second primary tumours or SPTs) in the upper aero-digestive tract (oral cavity, pharynx, larynx, trachea, lungs, oesophagus). SCC can be graded using the TNM classification (p. 314, Ch. 13). Treatment This requires a team approach. Surgeons work with oncologists as well as specialist nurses (e.g. Macmillan), speech and dietetic specialists, and the dental team. Considerable time needs to be spent with patients and their relatives to prepare them mentally and physically. They also need to feel part of the decision-making process. A range of treatment options are available; they are influenced by the stage of the tumour as well as patient factors. Potentially malignant disorders and carcinoma in situ. Treatment is usually by surgery, which, for these lesions, often has minimal morbidity and allows histological examination of the specimen. Larger areas may be best treated with laser excision. T1 and T2 lesions. With these lesions, surgery or radiotherapy (either teletherapy [external beam] or brachytherapy [radioactive implants]) have similar cure rates. T3 and T4 lesions. Larger tumours involving deep tissues; these have a much reduced cure rate. The best hope for cure with improved chances for local/regional control is with radical surgery and reconstruction followed by postoperative radical radiotherapy. Despite advances in reconstruction, some areas remain major problems for postoperative rehabilitation, e.g. base of tongue tumours. In these circumstances, tumours may be treated by either brachytherapy or http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 367 external beam radiotherapy possibly combined with concurrent chemotherapy or Cetuximab. This may give as good a chance of cure with better functional outcome. If bone is involved with tumour then surgery is usually preferred as radiotherapy is less successful in such cases. Neck metastases. If neck metastases are palpable, surgery is indicated. If there is no evidence of neck involvement on palpation (clinically N0), the risk of occult neck disease is still high (>20% for most oral sites), and most authorities advocate prophylactic treatment of the neck with selective neck dissection or external beam radiotherapy. Neck dissection is also recommended where access to the neck (e.g. for microvascular reconstruction of the oral defect) is necessary. Prognosis. is good for early small lesions treated properly, but if nodal metastases are present, the overall chance of cure decreases by 50%. The need for early diagnosis cannot be overemphasized. Careful screening of the oral mucosa to detect potentially malignant and malignant lesions should be carried out routinely in any oral examination. Cysts of the jaws A cyst may be defined as a pathological fluid-filled cavity lined by epithelium. A basic classification of cysts is contained in Table 14.4. Pathogenesis One theory suggests that central cell degeneration in a proliferating mass of epithelial cells sets up an osmotic pressure gradient and causes prostaglandin release. This promotes fluid accumulation. The other theory suggests death and degeneration of granulation tissue and then a similar progression. Keratocystic odontogenic tumours (previously known as ‘odontogenic keratocysts) tend to grow quickly and recur (25–60% of cases). This recurrence may be associated with rapid epithelial cell turnover in the cyst wall, common satellite cysts and a fragile cyst wall. Clinically cysts may present with a blue tinge in the overlying mucosa. http://dentalebooks.com 368 • C L I N I C A L D E N T I S T RY TABLE 14.4 Classification of cysts Odontogenic ‘Developmental’ Inflammatory Non-odontogenic Keratocystic odontogenic tumour (KCOT) Dentigerous (follicular) Radicular: apical lateral residual Paradental Nasopalatine Nasolabial (soft tissue) Non-epithelial (pseudo-cysts) Solitary bone cyst (haemorrhagic, idiopathic or traumatic) Aneurysmal bone cyst Stafne’s bone cavity Treatment A number of treatment options exist for cysts. Endontotic therapy There is good evidence that smaller apical radicular cysts will regress completely with adequate orthograde root canal treatment, however larger lesions will need to be enucleated along with a root apicectomy. Enucleation and primary closure If technically possible, this is the operation of choice as, if healing progresses uneventfully, no further intervention is needed. In smaller lesions the only problem usually encountered in raising the access flap is dissecting the soft tissue of the flap from the cyst wall tissues. Larger lesions may have to be dissected from antral lining, nasal floor or other structures, e.g. inferior dental nerve. Postoperatively, delayed healing and infection may be a problem if a large blood-filled cavity is left. Marsupialization In this procedure, the cyst is opened (by removing the roof) to allow continuity with the oral mucosa. Although it is technically easy, marsupialization may involve the patient in considerable postoperative care as the cavity must be cleaned regularly. It is advantageous in large mandibular lesions where surgical removal would put the inferior dental nerve (if not the integrity of the mandible) at risk and may allow preservation of adjacent teeth (Figure 14.9). http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 369 Figure 14.9 Marsupialization of large mandibular cyst. Pyramidal maxillary antrum Root apices within antrum Figure 14.10 The maxillary sinus (antrum) Unfortunately, marsupialization does not allow the whole lesion to be submitted for pathological examination. A high degree of suspicion should always remain when dealing with marsupialized cysts, and close follow-up with radiographic review is essential if other rare pathologies, e.g. neoplasia, are not to be missed. Maxillary sinus The maxillary sinus (Figure 14.10) can be visualized as pyramidal in shape with the apex of the pyramid projecting laterally into the zygomatic process of the maxilla. http://dentalebooks.com 370 • C L I N I C A L D E N T I S T RY The base is formed by the lower part of the lateral wall of the nose. The ostium draining the sinus enters the middle meatus. Cilia of the epithelium lining the sinus waft continuously to this exit. The mucoid film is replaced every hour. The healthy sinus does not contain microorganisms. History Think of the surrounding structures forming the pyramid. Look for pain, tenderness or swelling (which will be facial, intraoral [buccal or palatal], nasal or orbital). There may be nasal discharge, nose bleed or escape of oral liquid into the nose via the maxillary antrum. This last symptom suggests an oral-antral fistula. Eye symptoms include pain, epiphora and visual disturbance. Sensation of the skin or mucosa may be abnormal. Patients may also present complaining of toothache. Examination Pathology originating in the maxillary sinus may result in: swelling and tenderness leading to obliteration of the normal anatomy, e.g. nasolabial fold, buccal sulcus; loosening of maxillary teeth; in the edentulous patient denture fit is altered; maxillary teeth next to the sinus may be tender. The patency of the nasal airway should be checked, and the passage examined for the presence of a mass. Eye signs include proptosis, injection (reddening) and movement problems. Special tests • • • • • Vitality tests Fine needle aspiration of cells and fluid Radiography including occipitomental views at 15° and 30° as well as suitable intraoral views CT and MRI may be indicated Sinus endoscopy. Oral–antral fistula (OAF) A maxillary premolar or molar root may extend from the alveolus into the maxillary antrum. When the tooth is removed, an oral– antral communication may be created. Many of these communications close spontaneously by normal healing of the socket. Sometimes, however, a fistula is formed, which needs to be excised and closed surgically. A number of options for closing oral–antral communications exists. It is important to address any antral infection prior to any attempt at closure. Preoperative antral washouts can be very helpful. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 371 Closure of OAF Buccal flap with periosteal release (Figure 14.11) This is the most common flap used to cover an OAF from a tooth socket. The two relieving incisions buccally (1) are placed to diverge only slightly so that the flap will fit the usual space of one tooth diameter. A flap of mucosa and periosteum is then everted to expose the periosteum at the base, which is then detached (2) by an incision parallel to the base. The incision should cut only through the periosteum, leaving the flap pedicled on the relatively elastic mucous membrane and submucous tissue. The flap is then pulled over the tooth socket to meet the palatal mucosa and sutured in position (3) (numbers relate to Figure 14.11). Palatal rotation flap This flap is based on the greater palatine artery, and when swung into position leaves an area of denuded palatal bone. Buccal flap 2 Periosteal release 1 Relieving incision Direction of flap distension 3 Horizontal mattress suture Periosteal release Corner suture Figure 14.11 Periosteal release buccal flap repair of oral–antral fistula. http://dentalebooks.com 372 • C L I N I C A L D E N T I S T RY Buccal fat pad transfer This is an excellent reserve reconstruction for OAFs that have been subject to difficult or repeated attempts at closure. The fat pad is easy to find but mobilization should be done with care to preserve bulk and avoid the pterygoid plexus of veins. It can then be sutured into position. The fat pad becomes covered by oral mucosa by seeding of oral squames and growth from the margins. Buccal fat can be used in combination with a buccal flap to close large defects. Postoperative care Patients should be instructed not to blow their nose, to prevent any back pressure on the repair. Antibiotics are usually prescribed – broad-spectrum variety preferred – with scrupulous oral hygiene. Nasal inhalations using steam and a decongestant may help. Advise analgesics in the immediate postoperative period. Displacement of a fractured root into the maxillary antrum A potential complication of the extraction of maxillary posterior teeth is displacement of a fractured root into the maxillary antrum. Should fracture occur: • • • • • • remember which root you were working with, particularly in multi-rooted teeth is the fractured root still visible? if you can see it, can it be retrieved by careful suction? decide whether you will persevere in removing the root if not, and referral is some time in the future, then repair the OAF; sometimes a simple mattress suture is sufficient as an emergency measure in a small OAF. Alternatively, suture a small pack over the socket to give a watertight seal at the site where the tooth has disappeared into the antrum suitable radiographs of the socket area (at different angles) should be taken. To retrieve the root Raise an adequate flap designed to close the OAF following exposure and removal of the root. Remove appropriate bone to expose the root. Often the lateral socket/alveolus wall is a good place to look first. Roots can slip through this lateral wall and lie between periosteum and bone in the buccal sulcus. Radiographs will not define this problem easily. Careful examination of the lateral wall whilst raising the flap will help. If the root is well into the sinus, consider prompt referral to a specialist, as a Caldwell-Luc approach may be necessary. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 373 Fractured maxillary tuberosity Fracture of the maxillary tuberosity may occur during extraction of a posterior molar. If the bone cannot be dissected from the roots, it should be carefully dissected from the overlying mucosa and the tooth and tuberosity removed together. An extensive communication with the antrum results, but careful preservation of the mucosa leaves ample tissue to achieve a watertight closure. Postoperative treatment is as for OAF closure. Pre-prosthetic surgery The purpose of pre-prosthetic surgery is (in close communication with the prosthodontist) to correct any architectural problems in the oral cavity, which may lead to denture instability or retention problems. Conditions in which pre-prosthetic surgery may be required are shown in Figure 14.12. Bone irregularities Maxillary and mandibular tori Tori are localized developmental bony exostoses. Mandibular tori are located lingually in the premolar regions whilst palatal tori are found in the midline. Their presence may prevent insertion of a denture and they can be recontoured surgically. Local alveolar ridge architecture problems Often result from previous poor extraction technique (e.g. buccal plate removed along with tooth), resulting in overhanging areas and concavities. Bone irregularities can be recontoured by surgery (alveoloplasty) or grafting. Resorption problems In the maxilla. Resorption reduces the lateral and anteroposterior dimensions of the alveolus. Gross discrepancies can be corrected surgically. In the mandible. Both alveolar ridge shape and relationship with maxilla change. The alveolar ridge may have: an overall lack of height and width; knife edge or flabby ridges; concavities, particularly in the body region; more prominent genial tubercles; prominent mylohyoid ridges; an exposed mental nerve. Classification. Cawood classified alveolar resorption as: Class I – dentate process; Class II – post extraction; Class III – fully healed broad edentulous ridge; Class IV – narrow ridge; Class V – short ridge; Class VI – total loss of ridge. http://dentalebooks.com 374 • C L I N I C A L D E N T I S T RY 6 1 8 4 2 9 6 3 6 5 7 Hard tissue 1 Palatal torus 2 Mandibular torus 3 Genial tubercles 4 Prominent mylohyoid ridge 5 Thin knife edge ridge Soft tissue 6 Fraenula (various sites) 7 Denture-induced hyperplasia 8 Enlarged fibrous tuberosity 9 Superficial mental nerve Figure 14.12 Potential problems amenable to preprosthetic surgery. Soft tissue problems Problems that may require surgical correction include dentureinduced hyperplasia, loss of sulcus depth or prominent fraenula. Denture hyperplasia may regress following gross trimming of the denture and abstention from denture wear (if this is possible). However, there is often a residual fibrous mass, which requires surgical trimming. Take care not to remove too much mucosa in this situation. This is a delicate balance between removal, scar formation and loss of sulcus depth. Vestibuloplasty is used to deepen the sulcus; it may involve grafting. The management of local architecture problems and some soft tissue abnormalities too gross for prosthodontic management may be aided by placement of implants. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 375 Implants (See also Chapter 12) Implants are alloplastic materials that can be incorporated into the jaw bone. Materials include titanium, titanium coated with hydroxy­ apatite, or plasma-sprayed titanium. Dental implants are mainly used for support of prostheses. Commonly, 2–4 fixtures are inserted anteriorly into the mandible to support a full denture. Implants to replace single teeth are now commonly used. Facial or cranial implants can also be placed around the orbits or in the mastoid area to support other prostheses. Implants are locked solidly into bone by virtue of a direct interface between bone and implant – osseointegration. Achieving and maintaining this interface is essential for implant survival. For intraoral implants this means scrupulous oral hygiene. Factors influencing implant success Implant factors. They must be inert and biocompatible with oral tissue. Surgical factors. The precise fit of implant to bone is important, as is atraumatic surgery – in particular avoiding thermal injury to bone. The implant should be correctly sited to ensure optimal loading by the prosthesis. This requires careful cooperation with the prosthodontist. Soft tissue. The mucosa around the implant should be thin, relatively immobile and healthy – attached mucoperiosteum is best. Bone. The bone needs to be of sufficient depth and width to accept an implant. This may be a problem where there is gross resorption. There is usually sufficient bone in the edentulous maxilla in front of the maxillary sinus and in the mandible anterior to the mental nerve (Figure 14.13). There are various manoeuvres to deal with lack of suitable amounts of bone: anterior mandibular osteotomies and bone grafting with the implant as a stabilizer; surgical repositioning of the inferior dental nerve, prior to implant placement; sinus lift bone grafting to increase the bone available in the posterior maxilla. Bone density is reduced in the maxilla; because of this, a longer ‘sleep’ period may be required before loading of the implant. There is a slightly greater overall failure rate in the maxilla. Implant design is advancing. Implants which can be immediately loaded have been developed, as have shorter implants for use in areas with reduced amounts of bone available. Postoperative. A ‘sleep’ period may be required to allow osseointegration. The site must be protected from trauma by overlying dentures. http://dentalebooks.com 376 • C L I N I C A L D E N T I S T RY Anterior maxilla implant (usually Implants Implants in sufficient bone in mastoid orbital region here) region Dolder bar for lower denture–anterior mandible implant position does not compromise mental nerve function, and there is often sufficient bone here Bar for attachments Bone graft in antrum to accept more posterior implants in maxilla Bone graft in anterior mandible (horizontal osteomy) if insufficient bone Figure 14.13 Implants in the oral cavity and other sites. Prosthetic factors. Prosthetic aspects of implants are discussed in Chapters 12, 18 and 19. Maxillofacial trauma These patients must be referred urgently to a suitable hospital. Emergency receiving Dealing with patients suffering facial trauma can be difficult. There are three main points which need to be considered together: • cervical spine • airway • bleeding. The importance of these is closely followed by consideration of any other injury of significance to life, e.g. hidden haemorrhage from intraabdominal injury, fractured pelvis, femur, etc. Head injury must be considered, particularly if there is deterioration in the level of consciousness determined by history (from friend) or observation (Glasgow Coma Scale). If the patient arrives in obvious respiratory distress or with torrential haemorrhage these will obviously take precedence. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 377 For more major injuries you will be part of a team. However, many more minor referrals may come straight to you. Never forget to look for associated injuries in the head and neck and elsewhere. A patient with an apparently ‘simple’ fractured zygoma may actually have other consequences of the blow or other trauma and have sustained a significant head and/or other injury. Airway/cervical spine Emergency action will be as part of a team. It is essential to have good light and suction. Oropharyngeal or nasopharyngeal airways may help. Endotracheal intubation (if possible) definitively secures the passage. Beware base of skull fractures when cannulating the nose. An emergency surgical airway (cricothyroidotomy) may be needed, if other measures fail. Any suspicion of neck injury (beware – a lowered consciousness level may make history and examination difficult) makes temporary immobilization with collar or sandbags essential, or severe neurological damage or death could result. The following objects may be causing upper airway obstruction: foreign bodies such as teeth or denture fragments, vomit or blood. Anterior mandibular fracture and loss of tongue control may be helped (as a temporary measure, under LA) by wire ligatures applied to the teeth on the displaced fragment to permit repositioning. A tongue suture and anterior traction can be applied. A maxillary fracture may cause displacement of the maxilla downwards and backwards, and this can cause airway obstruction. Simple digital repositioning can allow the patient to breathe. Bleeding/Circulation Torrential nasal haemorrhage following mid-face fractures is rare but frightening. A mobile maxilla is best dealt with by resiting using finger pressure directed up and anteriorly on the palate. The maxilla can temporarily be stabilized by a mouth prop. Posterior nasal packs can then be placed (pass Foley catheters and inflate) and, finally, the anterior nose should be packed under pressure – nasal tampons such as Merocel are easy to place. Fluid replacement is essential (colloid or crystalloid) and often needed rapidly. Fluid replaced should be guided by the anaesthetist in charge. Signs of circulatory collapse are rarely due to maxillofacial injuries alone – check elsewhere. Consolidation Once any emergency stabilization has been accomplished, a more complete assessment may be undertaken. http://dentalebooks.com 378 • C L I N I C A L D E N T I S T RY History Remember to use witness accounts if necessary, e.g. was the patient ever conscious following the traumatic event? Examination If injuries are severe, keep reassessing the cervical spine (stabilization), airway (patency), vital signs (haemorrhage) and coma status. Usually one team member is assigned to this ongoing assessment. Specific oral and facial examination Extraoral. Assess any facial lacerations. Observe facial contours from above. Check/palpate: forehead; orbital rims; arch of zygoma; nasal contour and patency; medial canthal attachment and any telecanthus (separation of inner eyelid attachment); mandibular borders; mandibular movement. Check skin sensation changes: supraorbital and supratrochlear – forehead sensation; zygomaticofacial and temporal – lateral face and temporal region; infraorbital – cheek, lateral nose, upper lip and teeth/ gingivae of the maxilla; mental – lower lip and chin. If there is an eye or orbital injury consider ophthalmological referral. The most important test is acuity (each eye is tested for ability to read a series of standardized size texts). Note specific signs indicating base of skull fracture such as: bilateral ‘racoon eyes’; cerebrospinal fluid (CSF) leak; bruise behind ear (Battle’s sign). Intraoral. Note: areas of swelling and bruising; palpable steps in the bone contour; obvious occlusion derangements; gently ‘springing’ suspected areas of mandible and maxilla; injuries to the teeth. Radiographs. (Chapter 8) All fractures of consequence are usually diagnosed clinically, however, radiographic examination aids clinical assessment of fractures. The most common views are: maxilla – occipitomental (15° and 30°), lateral facial; zygomatico-orbital – occipitomental (15° and 30°); mandible – orthopantomogram, PA mandible. CT scans are particularly helpful in assessment of maxillary, orbital, naso-ethmoidal and condylar injuries. Glasgow Coma Scale (GCS) Levels of consciousness are measured using the Glasgow Coma Scale (GCS: Table 14.5). The scores for best motor response, best verbal response and eye opening should be added together. The total GCS score for a normal patient is 15. GCS gives a method of repeatable assessment so improvement or deterioration can be noted. Care must be used in assessing patients who may also be hypotensive, intoxicated with drugs (including alcohol) or hypoxic. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 379 TABLE 14.5 The Glasgow Coma Scale Best motor response Best verbal response Eyes open Obeys commands 6 Localizes pain 5 Orientated 5 Normal flexion to pain 4 Confused conversation 4 Spontaneously 4 Abnormal flexion to pain 3 Inappropriate words 3 To speech 3 Extension to pain 2 Incomprehensible 2 To pain 2 None 1 None 1 Do not open 1 Lacerations Good documentation is essential, not least for medico-legal purposes. A photograph or diagram with measurements is best. Facial skin has a very good blood supply from a rich interconnecting subdermal plexus of vessels. This means that pieces of skin survive on the face, which may not in other areas. Never discard skin unless you are very sure of the final reconstruction. Cleaning is very important. Any cleaning solutions should be used only on the intact skin (beware entry into the eyes). In the wound itself use normal saline. Take care to recognize tattooing, particularly with road dirt. A large scalpel blade to scrape skin margins, or used tangentially on abrasions can be very helpful. Underlying structures need consideration, particularly: facial nerve (VII); parotid duct; tarsal plates and eyelid muscles; cartilage skeleton of the pinna. Treatment may be possible under LA (e.g. block anaesthesia at supraorbital, infraorbital or mental nerves) but can be very time consuming. Large involved areas or younger patients may need a GA for optimal management. Remember to check tetanus prophylaxis. Facial skeleton fractures Classification Fractures may be classified generally as: simple; compound; comminuted; greenstick; pathological. Mandibular fractures. Classified according to site: condyle; angle; body; parasymphysis; symphysis; dentoalveolar; coronoid; ramus. Maxillary (middle third of face). Fractures described as: Le Fort I; Le Fort II; Le Fort III (Figure 14.14). http://dentalebooks.com 380 • C L I N I C A L D E N T I S T RY Le Fort III Le Fort II Le Fort III Le Fort III Dentoalveolar fracture Le Fort I Figure 14.14 Fractures of the maxilla. Orbital floor/wall implant Miniplate Miniplate Arch bars with inter maxillary wire fixation Figure 14.15 Stabilization of facial fractures. Zygomatic complex fractures. Classified as: arch; zygomaticoorbital; orbital. Nasal fractures. Classified from anterior progressing posteriorly: cartilaginous; cartilage + nasal bones; complex naso-orbital-ethmoidal. Treatment As with any bone fracture, treatment involves: reduction; fixation and immobilization; prevention of infection; return to function (see Figure 14.15). http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 381 Treatment may be closed or open, depending on the need to expose the fracture site for accurate reduction and fixation. The amount of fracture distraction usually determines whether a closed manipulation with external fixation will suffice. External fixation may be maxillo-mandibular wire fixation using the dentition to help locate the bite and stabilize a relatively undisplaced jaw fracture, or external pin fixation connected across a fracture site. Other factors influencing choice of fixation for fracture treatment include recovery facilities, expertise in dealing with patients whose jaws are wired closed and patient preference. In most situations the main consideration is anatomical reconstruction. If indicated, open approaches and internal fixation (using plates and screws to hold the reduced fracture in place) usually achieve this best. Access to the facial skeleton is often gained via intraoral incisions to avoid facial scars. The buccal sulcus in the maxilla and mandible is often used with a facial degloving technique to reach the fracture site. More severe zygomatico-orbital, naso-ethmoidal and transcranial (e.g. frontal sinus) fractures may need facial incisions such as: upper or lower eyelid, crowsfoot, or a more extensive coronal approach. The temporomandibular joint (TMJ) (Figure 14.16) Acquired conditions of the TMJ Temporomandibular disorder (TMD) Myofascial pain See p. 322. Meniscus External Glenoid (anterior and Articular auditory fossa posterior band) eminence Zygoma canal Lateral pterygoid muscle Lingula Mandibular condyle Mastoid Bilaminar Lateral aspect Anteromedial zone aspect Figure 14.16 Anatomy of temporomandibular joint. http://dentalebooks.com 382 • C L I N I C A L D E N T I S T RY Internal meniscal derangement Osteoarthrosis Arthritis Dislocation This is movement of the mandibular condyle over and anterior to the articular eminence of the glenoid fossa. The condyle is prevented from returning to the fossa by ‘protective’ vertical muscle spasm. Treatment. Acute dislocation can be reduced by placing the thumbs on the lower molar teeth and rotating downwards and backwards. Sedation may relax muscle spasm and aid relocation. Patient education to avoid opening too wide may be of benefit in cases of recurrent dislocation. A variety of surgical procedures, which include eminectomy and eminence augmentation, have been described when persistent dislocation is a problem. Fracture Condylar neck. May be high or low (subcondylar). These are amongst the most common mandibular fractures. Diacapitular (intracapsular). These involve the condylar head. In children under 5 years old this is the only possible fracture because of the anatomy of the developing mandible (there is no real condylar neck, and a soft, large condylar head). There may be a risk of ankylosis and/or compromised mandibular growth leading to asymmetry. Treatment. This depends on the occlusion, degree of displacement and operator experience. Dislocated fractures and those with loss of ramal height and occlusal problems should be considered for open reduction. Ankylosis True. Caused by joint pathology (usually trauma or infection). True ankylosis may be bony or fibrous. Usually, there is some movement (1–3 mm) even in gross bony fusion. False. Caused by pathology outside the joint such as: myogenic, e.g. postoperative damage to muscles; neurogenic, e.g. cardiovascular accident (stroke); psychogenic, e.g. hysteria; bone impingement, e.g. coronoid hyperplasia; fibrous adhesions, e.g. post trauma and infection; tumours, e.g. oral squamous cell carcinoma invading medial pterygoid muscle. Treatment. This is by surgery, where indicated, to release the anatomical obstruction. Reconstruction may be necessary, e.g. gap arthroplasty or total joint replacement. In childhood, surgery should be performed as soon as practicable to reduce secondary developmental deformity. If gross retrognathia has occurred, this may be http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 383 corrected with distraction osteogenesis and/or conventional orthognathic procedures. Congenital conditions of the TMJ These are rare, e.g. craniofacial (hemifacial) microsomia, which has a varying lack of development of the condyle and ascending ramus associated with other bony underdevelopment (e.g. ossicles of middle ear, zygoma and temporal bone) and surrounding muscles of mastication and facial nerve. Facial and dental asymmetry (Figure 14.17) Differential diagnosis Congenital (intrauterine growth). e.g. craniofacial microsomia, cleft lip and palate. Developmental (growth post birth). e.g. hemimandibular or hemifacial hypertrophy, condylar elongation, condylar trauma or infection ± ankylosis. Occlusal cant – an intact occlusion that facial growth (or lack of growth) has adapted to circumstances, resulting in a slope between one side of the occlusion and the other. Open bite. – lack of occlusion which may result from recent trauma, excessive growth or continuing habit, e.g. thumb sucking. May be compensated in a growing child. Compensation often leads to a facial asymmetry as growth is held back in one area (e.g. unilateral condylar trauma). Careful analysis will determine the correct diagnosis. For example, unilateral condylar trauma with ankylosis in the growing child will not show a deformed pinna. Orbital and cranial asymmetry is found in craniofacial microsomia. Look for — Cranial/forehead asymmetry Mandibular angles (palpate) Occlusal cant Orbital asymmetry Levels of external auditory meatus Nasal asymmetry Lips asymmetry Chin point asymmetry Figure 14.17 Facial and dental asymmetry. http://dentalebooks.com 384 • C L I N I C A L D E N T I S T RY Orthognathic and cleft surgery (Chapter 16) Orthognathic surgery Facial disproportion often arises from hard tissue discrepancies. These may be in any dimension: AP, vertical or transverse. Surgery to the facial skeleton can radically alter function and appearance. Patients are treated in collaboration with orthodontists. Indications Function. This may be interceptive surgery during growth to encourage further, more normal, growth as in costochondral grafting in craniofacial microsomia and muscle reconstruction in cleft surgery. Functional correction may also be indicated once growth has ceased, e.g. to correct an anterior open bite, an overjet/overbite problem, or a crossbite which may improve mastication and speech. Aesthetics. Of increasing importance. In some cases, psychiatric or psychological assessment and guidance will be needed. Planning. Careful planning and assessment is required before undertaking orthognathic surgery. The function of a planning clinic is to facilitate communication between the patient, the surgeon and the orthodontist. History. Include as detailed an account of the patient’s problems from their perception as possible. Examination Head and neck assessment. An idea of overall proportions is obtained, with the face in repose, especially the lips. The head should be in the natural head position (sit upright, relax and look straight ahead into a mirror). Intraoral assessment. Orthodontic; oral hygiene and dental health. Other assessments. Speech; nasal function; hearing; psychological; maxillofacial technical assessment. Special tests. Radiographs, e.g. lateral and AP cephalograms and orthopantomograms; photographs (e.g. 3-D imaging); dental models and facebow transfer. Planning takes into account all the information gleaned. Model surgery (Figure 14.18) allows visualization of proposed procedures. Treatment Hard tissue discrepancy. A number of osteotomies are possible, but the most common procedures are listed in Table 14.6 Grafting or bone sculpture is performed to augment or reduce areas. Soft tissue discrepancy. This may be corrected either at the time of hard tissue correction or later. Augmentation is possible with flaps, fat http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 6 6 5 4 1 2 3 1 Sagittal split 2 Vertical subsigmoid 3 Genioplasty 4 Le Fort I 5 Le Fort II 6 Le Fort III Vertical subsigmoid osteotomy (back) Sagittal split osteotomy (advance) Le Fort I osteotomy Figure 14.18 Orthognathic surgery procedures. http://dentalebooks.com 385 386 • C L I N I C A L D E N T I S T RY TABLE 14.6 Classification of surgery to correct facial deformity (Numbers refer to Figure 14.18) Mandibular surgery Sagittal split osteotomy 1 Vertical subsigmoid osteotomy 2 Body ostectomy Genioplasty 3 Maxillary surgery Le Fort I osteotomy 4 Le Fort II osteotomy 5 Le Fort III osteotomy 6 Segmental surgery Premaxillary osteotomy: premaxilla moved Posterior maxillary osteotomy: allows posterior alveolar segments to be repositioned Lower labial segment surgery: allows for repositioning of lower six anterior teeth Upper or lower midline split: allows for arch widening or narrowing • • • • transfer, collagen and similar injection/implants. Reduction involves excision, lipectomy, liposuction. Cleft lip and palate The management of cleft lip and palate is discussed in Chapter 15. Cleft surgery A complete cleft of lip and palate crosses many structures with developmental, functional, aesthetic and psychological consequences. Various surgical procedures are involved in reconstruction to improve alignment, function and appearance with particular attention to muscle reconstruction in soft palate and lip. Surgery will result in scarring which impedes growth and development. Developments in technique have focused on improving function by reconstructing the anatomy while reducing scarring and maximizing growth potential. The anatomy of cleft lip and palate are shown in Figure 14.19. Surgical interventions include. first 6 months of life – lip/nose and soft palate reconstruction; within 12 months – palate totally closed; evidence of middle ear problems – drainage operations; speech problems – may need palatal revision/pharyngoplasty; alveolar cleft – bone graft during mixed dentition; alveolar collapse/jaw deformity – orthognathic surgery; residual nasal/lip problems – revision surgery. http://dentalebooks.com O ral and m a x illo f acial s u r g ery Abnormal muscle insertions • 387 Nasalis muscle Levator muscles Lip Orbicularis oris muscle Abnormal muscle insertions Alveolus Remnants of tensor aponeurosis Hamulus Tensor palatini muscle Levator palatini muscle Palatopharyngeus muscle Figure 14.19 Anatomy of cleft lip and palate. A comprehensive team approach is needed for the management of cleft lip and palate patients. This management should take place in a regional specialist centre. Reconstruction A variety of techniques and materials are available to aid in reconstruction and repair of tissue defects in the head and neck region. Techniques for reconstruction include: no intervention – leave to granulate, e.g. soft tissue defect on the hard palate; obturation – e.g. prosthesis in maxillary defect; skin grafting (full or partial thickness); local flaps; regional flaps; free flaps. Flaps Flaps may be classified according to their blood supply (random or axial), their composition (e.g. cutaneous, myocutaneous), their design (e.g. rhomboid, bilobed) and distance from the defect (local, regional, distant/free). Random pattern. This type of flap relies on random pattern blood vessels in the subcutaneous tissue for survival. Axial pattern. These flaps can be of much greater length as the pedicle is designed to incorporate specific vessels (artery and vein). Regional flaps. A variant of axial pattern flaps; e.g. pectoralis major myocutaneous flap taken from the lower chest wall and rotated up to http://dentalebooks.com 388 • C L I N I C A L D E N T I S T RY be passed under a skin pocket in the neck to be used for reconstruction of a defect in the mouth. Free flaps. This sort of reconstruction has an isolated vascular pedicle; however, this pedicle is divided and the vessels re-anastomosed to arteries and veins in the neck, e.g. the radial forearm fasciocutaneous flap. These techniques allow a greater choice of reconstructive options. The selection of which flap to use in a reconstruction depends to some extent on what tissues have been removed. There are free flaps that can replace skin, bone or muscle, or any combination of these; e.g. free fibula reconstruction of the mandible, with or without skin, depending on the need for any soft tissue replacement. Grafts Autogenous grafts. Use the patient’s own tissue: skin grafts – splitskin graft, full-thickness skin graft; bone grafts – cancellous, corticocancellous; grafts grown in tissue culture ‘to order’, e.g. skin for patients with extensive burns. Allografts. Tissue from a human donor specially prepared to reduce abnormal antigens: bone grafts; cartilage grafts. Heterografts. Tissue from another species, again treated to reduce any recipient immune reaction. Specially bred animals, with genetically manipulated compatibility genes to overcome rejection problems, may make these grafts more popular. Alloplastic materials. These should be biocompatible. Materials used include: Internal fixation plates and screws. Titanium, stainless steel, cobalt– chromium. Resorbable materials. Sutures, internal fixation screws and plates: polyglycolic acid (Dexon), polyglycolic/polylactic acid (Vicryl), poly-pdioxanone (PDS). Orbital wall/floor reconstruction material. Vicryl sheet, PDS sheet, titanium mesh. Bone substitutes. Ceramics, hydroxyapatite. Contour materials. Gore-tex, Proplast, Medpor (porous polyethylene). Soft tissue crease/wrinkle obliterative materials. Collagen. Salivary glands Salivary gland disorders are discussed in Chapter 13. http://dentalebooks.com O ral and m a x illo f acial s u r g ery • 389 Surgical management Surgical management of salivary glands includes: Enucleation Of, for example, benign minor salivary gland pathology (e.g. mu­­ cocele). Operations on the duct Meatoplasty. To open up a constricted orifice. Ductal reimplantation. Sometimes used in sialorrhoea. Removal of stone. Most commonly performed in the submandibular duct. The more proximal (near the gland), the more difficult to remove the stone. Place a suture behind the stone and put on tension to prevent posterior displacement; incise through floor of mouth mucosa; dissect to reveal the duct (beware vessels and lingual nerve); identify stone in duct and incise wall; remove stone; do not suture. Endoscopic removal of small distal stones via the duct orifice is also possible. Excision of gland Parotidectomy. Usually performed superficial to the facial nerve. In tumour surgery an attempt is made to leave a cuff of normal parotid tissue round the tumour. There is usually at least one branch of facial nerve adjacent to the tumour, and this means a very careful dissection and no formal cuff of gland in this area of the excision. Transient damage to at least this branch of the facial nerve is usually expected. Sensory nerve damage to greater auricular (cervical plexus) and auriculotemporal (trigeminal) nerves may also occur. Frey’s syndrome – sweating of the overlying cheek skin as a result of salivary stimulation (gustatory sweating) – results from secretomotor nerves which previously supplied the salivary gland, healing to innervate the sweat glands. A cosmetic defect (depression of the posterior cheek) may also be a concern for the patient. There is now good evidence that most benign parotid tumours (e.g. pleomorphic adenoma) may be removed by extracapsular dissection (removal of tumour only, with preservation of normal gland tissue), reducing the incidence of complications without increasing the risk of recurrence. Submandibular gland excision. This is performed much more often for infection (sialadenitis) associated with stone obstruction (sialolithiasis). The nerves at risk from this dissection are the marginal mandibular (branch of the facial – VII – nerve), the lingual (branch of the trigeminal – V – nerve) and very rarely the hypoglossal – XII – nerve. http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Orthodontics Introduction 391 What is malocclusion? 391 Risk/benefit considerations in orthodontic treatment 394 Classification and occlusal indices in orthodontics 396 Patient assessment/examination 400 Cephalometrics 403 Principles of treatment planning 405 Management of the developing dentition 407 15 Class I malocclusion 410 Class II division 1 malocclusion 412 Class II division 2 malocclusion 413 Class III malocclusion 415 Removable appliances 417 Fixed appliances 422 Functional appliances 423 Orthodontic management of cleft lip and palate 424 Orthodontic aspects of orthognathic surgery 427 Introduction What is orthodontics? Orthodontics is the specialist branch of dentistry concerned with the growth and development of the face and dentition, and the diagnosis, prevention and correction of dental and facial irregularities. The development, prevention, and correction of irregularities of the teeth, bite and jaw (GDC). What is malocclusion? Malocclusion is considered to be a variation of normal – so not all malocclusions require treatment. Treatment is considered when there is functional or aesthetic impairment. Orthodontic treatment is also increasingly used to treat facial deformities, usually in com­ bination with orthognathic surgery, and to facilitate restorative pro­ cedures (orthodontic-restorative interface). Malocclusion is a term introduced by Edward Hartley Angle and is defined as any deviation of the occlusion from the ideal. http://dentalebooks.com 392 • C L I N I C A L D E N T I S T RY Prevalence of malocclusion Based on morphology. The UK population can be classified as: Class I Class II division 1 Class II division 2 Class III 50–55% 25–33% 10% 3% using the British Standards Institute’s Incisor Classification (p. 397). Based on need for treatment. Assessment of 12-year-old children using the Index of Orthodontic Treatment Need (IOTN) – Dental Health Component (p. 398): one-third of children have a malocclu­ sion showing a need for treatment; one-third have malocclusions which have borderline need for treatment; one-third have a maloc­ clusion with little or no need for treatment. Who provides orthodontic care? All dental clinicians must be ‘orthodontically aware’. Orthodontic appliance treatment is increasingly provided by specialists, often with the help of an orthodontic therapist, but the general dental practi­ tioner (GDP) has a vital role to play. The GDP is the gatekeeper to orthodontic care and should be competent in the appropriate moni­ toring and recognition of malocclusion, as timely referral or treat­ ment can alleviate orthodontic problems. The role of the GDP in orthodontics includes continuing preventive care, ‘orthodontically appropriate’ operative treatment such as management of primary molar problems, appropriate assessment of first permanent molars, monitoring of the developing occlusion, and simple treatment skills – often in conjunction with advice from a specialist. Good dental health is an essential prerequisite for future orthodontic treatment. The GDP will often wish to refer patients for advice or treatment. If in doubt, refer sooner rather than later, and before carrying out any intervention. The most difficult orthodontic problems are often those that have been referred too late, or have had previous unsuccessful or inappropriate orthodontic treatment. The GDP may refer to specialists working within primary or secondary care. Not all patients with a malocclusion require orthodontic treatment. http://dentalebooks.com O rt h odontics • 393 Timing of orthodontic intervention When orthodontic treatment should be carried out is related to the type of problem and the developmental stage of the dentition. Primary dentition. Treatment is rarely indicated in the primary dentition. Possible exceptions include a malpositioned tooth causing marked mandibular displacement, supernumerary teeth, severe skeletal dis­ crepancies or asymmetry (e.g. hemifacial microsomia). Early mixed dentition. Occasionally involves extraction of primary teeth, or interceptive procedures such as correcting a crossbite. Late mixed/early permanent dentition. Most treatment is carried out at this stage. Later treatment. Treatment involving orthognathic surgery is undertaken at the completion of growth. Treatment in adults is also increasingly being undertaken for cosmetic concerns and to facilitate restorative treatment. Why do orthodontic treatment? The many benefits of undertaking orthodontic treatment include: • • • • • improvement in function reducing risk of traumatic injuries to protruding upper incisors management of impacted teeth relief of crowding to facilitate oral hygiene psychological benefits of improved dentofacial aesthetics. Risks of orthodontic treatment include: • • • enamel decalcification root resorption (occasional devitalization) relapse. A risk-benefit analysis must be undertaken before embarking upon any course of treatment. Sometimes the GDP may be called upon to provide a second opinion to decide if a patient should undergo treatment if there are dental health issues or concerns around compliance. Scope of orthodontic treatment Orthodontic treatment can be considered under the following headings: • Monitoring of the developing dentition. Interceptive treatment to avoid or simplify later treatment, e.g. ectopic canines, poor prognosis first permanent molars. • Management of problems of intra-arch alignment, e.g. crowding, spacing, ectopic teeth, transpositions. http://dentalebooks.com 394 • • • • C L I N I C A L D E N T I S T RY Management of problems of inter-arch alignment, e.g. overjet, overbite, midlines, crossbites. Management of skeletal discrepancies – in mild to moderate cases this may involve orthodontic camouflage and in severe cases this may require a combination of orthodontics and orthognathic surgery. Multidisciplinary orthodontics – orthodontic tooth movement to facilitate restorative dentistry, management of periodontal tooth migration, craniofacial deformity and orthodontic appliances to facilitate management of obstructive sleep apnoea by mandibular posturing. Risk/Benefit considerations in orthodontic treatment Potential benefits of orthodontic treatment Can be categorized as: improved dental health/function; improved appearance. Improved dental health/function Orthodontic treatment has a number of possible dental health/ functional benefits: Masticatory function. Mild to moderate malocclusion is unlikely to significantly affect masticatory efficiency. Severe malocclusion (e.g. anterior open bite; large overjet, reverse overjet) may make incision of food more troublesome and may produce social embarrassment. Dental caries. Significantly displaced teeth may predispose to plaque retention, which may increase the risk of dental caries. Periodontal disease. Significantly displaced teeth may predispose to plaque retention, which may increase the risk of periodontal damage. Overjet. There is evidence that anterior teeth with an increased overjet (>6 mm), and particularly when the lips are incompetent, are considerably more likely to suffer trauma. Peak incidence is before 10 years and unfortunately treatment is not commonly provided by this age. A slight increase in plaque accumulation on teeth having either an increased or reverse overjet has also been shown. Temporomandibular joint dysfunction (TMD). (See Chapter 14, p. 381) There is little evidence to suggest that malocclusion has any significant effect, or that orthodontic treatment brings any lasting benefit, on TMD. Tooth impaction. Orthodontic treatment may be used to prevent and correct tooth impaction. Overbite. Increased overbite may cause soft tissue damage to the palatal or lower labial mucosa. http://dentalebooks.com O rt h odontics • 395 Anterior crossbite. Accelerated gingival recession may occur around lower incisors related to upper incisors in linguo-occlusion. There is also a greater risk of attrition at the site of a premature contact. Conclusion. The threat posed to dental health by malocclusion is generally modest. However, in some specific malocclusion traits there is the potential for significant damage. Improved appearance Malocclusion affecting appearance may also affect an individual’s self-esteem, elicit an unfavourable social response or provoke negative stereotyping. Self-esteem. Only limited information is available regarding the link between level of malocclusion and self-esteem. However, there is great variation between individuals’ perception of their appearance. Social response. Teasing may affect personality development. Stereotyping. It has been shown that faces evoke a more favourable response when there is normal anterior dental alignment, but that the level of background facial attractiveness is of greater importance. Conclusion. This is a difficult topic to investigate; intuitively it would seem that the chances of evoking an unfavourable social response are greater with more conspicuous dental defects. Potential risks of orthodontic treatment Risks of orthodontic treatment include: Decalcification. Especially around fixed appliances if plaque control is poor and if the frequency of sugar intake is excessive. Caries is entirely preventable (Chapter 3) – all potential orthodontic patients must achieve and maintain excellent oral hygiene, avoid sugar in between meals and use fluoride preparations. It is essential that regular dental visits are maintained throughout orthodontic treatment. Root resorption. A small degree of root resorption (1–2 mm) occurs in the majority of people during orthodontic treatment. Rarely, root resorption can be a significant problem in some cases and is more likely with fixed than removable appliances. Use of heavy forces and a history of trauma may be predisposing factors. Gingival problems. Mild gingivitis in patients wearing fixed appli­ ances is common. This is reversible, but requires careful control. Per­ manent loss of attachment can occur in some cases, particularly if teeth are moved outside of the arch or excessively tipped. http://dentalebooks.com 396 • C L I N I C A L D E N T I S T RY Pulp damage. Minor circulatory changes commonly occur during orthodontic treatment. In very rare circumstances this may lead to loss of vitality (e.g. previous trauma). Ulceration of the oral mucosa. May arise from fixed appliance com­ ponents. Patients prone to oral ulceration (e.g. Epidermolysis bullosa) must embark upon treatment with care. Facial profile changes. Inappropriate retraction of the incisors may lead to ‘flattening’ of the facial profile. Enamel damage at debond. There is the potential for enamel damage when brackets are removed at the end of treatment. Headgear injury. Dislodged headgear can cause facial and ocular injury. It is essential that safety features such as the Masel safety strap, snap away modules, recurved Khloen bow and locking Khloen bow are used. Temporomandibular joint dysfunction. (See Chapter 14, p. 381) There is no strong evidence that orthodontic treatment can cause or treat temporomandibular joint problems. Relapse. Without the long-term use of retainers, orthodontic treat­ ment is prone to relapse due to the elastic recoil of periodontal fibres, late mandibular growth and soft tissue maturational changes. Treatment failure Treatment failure in orthodontics may mean a failure to meet the occlusal objectives, the occurrence of excessive damage (see Risks of Orthodontics) during treatment, and poor patient satisfaction with the outcome (e.g. flattening of the profile). A number of factors can contribute to treatment failure including poor diagnosis and treat­ ment planning, poor patient co-operation, unfavourable growth and poor communication. Conclusion. Orthodontic treatment should only be undertaken after careful consideration of the risks and benefits of treatment. To mini­ mize the risks of treatment, it is essential that orthodontic treatment is only embarked upon in those with excellent oral health. It is essen­ tial to have good patient compliance for treatment to be successful. In the long-term, retention is essential for maintaining the results of orthodontic treatment. Classification and occlusal indices in orthodontics An occlusal index is a rating or categorizing system that assigns a numerical or alphanumerical label to an individual’s occlusion. http://dentalebooks.com O rt h odontics Class I Class II div. 1 Class II div. 2 • 397 Class III Figure 15.1 Incisor classification. Skeletal pattern 1 Skeletal pattern 2 Skeletal pattern 3 Figure 15.2 Skeletal patterns. Numerous types of index have been developed. Whilst some are used to classify malocclusion for diagnostic purposes, e.g. British Standards Institute’s Incisor Classification (Figure 15.1) and Skeletal Classifica­ tion (Figure 15.2), other indices are designed to measure treatment need, e.g. Index of Orthodontic Treatment Need (IOTN) or treatment outcome, e.g. Peer Assessment Rating Index (PAR). Incisor classification The British Standards Institute’s (1983) classification of malocclu­ sion, based upon the relationship of the lower incisor edges and the cingulum plateau of the upper central incisors (see Figure 15.1), is a useful index for the classification of malocclusion as it is based on the anterior teeth which are most visible to the orthodontist and patient: Class I. The lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors. Class II. The lower incisor edges lie posterior to the cingulum plateau of the upper central incisors. http://dentalebooks.com 398 • C L I N I C A L D E N T I S T RY N S Po Or Ba Ar PNS Go Me ANS A B Pog Facial plane Frankfort plane Maxillary plane Functional occlusal plane Mandibular plane Figure 15.3 Cephalometric points and planes. Class II division 1. The upper central incisors are proclined or of average inclination and there is an increased incisor overjet. Class II division 2. The upper central incisors are retroclined; the overjet is usually minimal but may be increased. Class III. The lower incisor edges lie anterior to the cingulum plateau of the upper central incisors; the overjet is reduced or reversed. Skeletal classification The skeletal classification (See Figure 15.2) relates the anterior limit of the mandibular base to the maxillary base with the head in the Natural Head Position; Class I skeletal pattern. Point B lies a few millimetres behind point A (Figure 15.3). The lower skeletal base lies a few millimetres behind relative to the upper. Class II skeletal pattern. The lower skeletal base is retruded (>2mm) relative to the upper. Class III skeletal pattern. The lower skeletal base is protruded rela­ tive to the upper. Index of orthodontic treatment need (IOTN) The IOTN has two components, which can be assessed clinically or on study models: • • Dental Health Component (DHC) Aesthetic Component (AC). http://dentalebooks.com O rt h odontics • 399 Dental Health Component (DHC) of IOTN The DHC records the various aspects of malocclusion according to a hierarchy using the MOCDO acronym, where: M= O= C= D= O= Missing teeth Overjet Crossbite Displacement of contact points Overbite This provides a reliable and rapid method of assessing the occlu­ sion. A specifically designed measuring ruler is used and a grade awarded on the basis of the single most severe feature of the maloc­ clusion. The index has been validated as follows: Grades 1, 2 Grade 3 Grades 4, 5 No/slight need for treatment Borderline need Need for treatment Limitations. There is a shortage of scientific evidence to justify the hierarchy of the scale based upon dental health grounds. Nonethe­ less, the DHC of IOTN provides a structured method for assessment of malocclusion. Aesthetic component of IOTN The aesthetic component scores the need for treatment on the grounds of aesthetic impairment of the anterior teeth. The patient’s teeth are compared with 10 standard photographs ranked in order of attractiveness, 1 being the most attractive and 10 the least aes­ thetically pleasing. The scale has been validated as follows: Grades 1, 2, 3, 4 Grades 5, 6, 7 Grades 8, 9, 10 No/slight need Borderline need Need At present the UK National Health Service funds orthodontic treatment for children where the IOTN is equal to or greater than DHC = 3 and AC = 6 (3.6). Potential uses of IOTN Resource allocation. Enables identification of those most in need of treatment. Uniformity of assessment. Offers an objective structured assess­ ment of malocclusion and the need for intervention. Screening. Can be used by GDPs for screening purposes. Patient advice. May be used to provide objective advice to a potential patient. The aesthetic component in particular can be used as a scale http://dentalebooks.com 400 • C L I N I C A L D E N T I S T RY to advise patients who may have unrealistic concerns about the appearance of their teeth. Peer assessment rating index (PAR) Used to determine orthodontic treatment outcome based upon dental-occlusal changes. The PAR index grades features of the preand post-treatment study models to derive a score of the improve­ ment achieved with treatment. It measures the following features of the malocclusion: • • • • • overjet overbite centreline relationship buccal segment relationship upper and lower anterior alignment. Limitations. PAR is based solely on study models and does not account for changes in facial profile, iatrogenic damage, tooth incli­ nation, arch width or posterior spacing, and is not appropriate for assessment of mixed dentition treatment. Patient assessment/examination The features of taking a history and examining a patient outlined in Chapter 7 apply. However, the following features are specifically rel­ evant to an examination for orthodontic purposes. The aims of orthodontic assessment are to document and evaluate facial, occlusal and functional characteristics, to decide if there is a problem and, if so, what action is required. Notably important times for orthodontic examination are: early mixed dentition; early permanent dentition. As always, a logical structured approach must be followed to gather all the information efficiently and to ensure important fea­ tures are not overlooked. The following sequence should be employed. Patient background Note. Age; relevant medical history; relevant dental history, e.g. attendance record, oral hygiene, caries rate, trauma; social history: is there a complaint from the patient? Does the patient appreciate what orthodontic treatment involves? Level of parental support? Any friends/siblings having treatment? Clinical examination Extraoral examination Need to consider hard and soft tissues. http://dentalebooks.com O rt h odontics • 401 Hard tissues Assessment is aimed at noting any disproportion or asymmetry. The skeletal pattern has an important effect on the dental arch relation­ ship and should be assessed in three dimensions with the head in a natural head position: Anterior–posterior. The relationship of the maxillary skeletal base to the mandibular base can be assessed in the profile view. Vertical. Need to assess the Frankfort–mandibular plane angle (normal, reduced, increased) and the lower facial height. The dis­ tance from a point between the eyebrows (glabella) to the base of the nose (subnasale) should be approximately equal to that from sub­ nasale to the underside of the chin (soft tissue menton), though normal variation exists. Symmetry. (view from the front) Is there any significant asymmetry? Asymmetry in the lower part of the face can be due to true skeletal asymmetry, a lateral displacement of the mandible on closure, or a combination of both. Soft tissue asymmetry may also be a contribu­ tory factor. Soft tissues Lips. Lip contour Normal, everted, vertical? Lip line Where is the top of the lower lip relative to the incisors? Should cover about a third to a half of the upper central incisor crowns. Lip seal Are the lips com­ petent (i.e. together with minimal muscular effort) with the mandible in the rest position? An attempt should be made to assess lip activity during swallowing. Beware of cases with marked lip ‘incompetence’, as the stability of upper incisor retraction may be questionable. Tongue. This may be difficult to examine. Some positions of tongue activity can be inferred from the occlusion. With incompetent lips the tongue will tend to come forward to help maintain the anterior oral seal (adaptive tongue thrust). By the end of the extraoral examination, a reasonable idea of what occlusal characteristics to expect should have been obtained. If they differ from the expected, ask why? Intraoral examination Look at general features of dental health such as the level of oral hygiene, caries experience, gingival condition, tooth number and form and the size and condition of any restorations. Then examine each arch in isolation, followed by the two arches in occlusion. Lower arch Labial segment. Count the teeth, assess crowding and the inclination of the incisors. http://dentalebooks.com 402 • C L I N I C A L D E N T I S T RY Buccal segment. Observe alignment problems (potential and present) and angulation of the canines. Upper arch Labial segment. As for lower arch. Buccal segment. Determine angulation of the canines, note align­ ment problems; if the permanent canine is unerupted, is it palpable bucally? In occlusion. Check the path of closure as the teeth are brought together. Is there a premature contact and associated mandibular displacement? Incisor relationship. Classify this according to British Standards Institute’s Incisor Classification (p. 397). Overjet. Measure to the nearest millimetre. Overjet Relationship between the incisors in the horizontal plane. Overbite. Is it average, increased or reduced; complete or incomplete? Overbite Relationship between the incisors in the vertical plane. Centrelines. Check the relation of each dental midline to the facial midline and also to each other. Arch anterior/posterior relationship. Check the canine and buccal segment relationship. Arch buccolingual relationship. Check for any crossbites. If there is a posterior crossbite, is it bilateral or unilateral, and is there an associ­ ated displacement? TMJ assessment. An assessment should be made of any TMJ and myofascial symptoms or signs. Diagnostic records The following diagnostic records will aid assessment of the patient’s orthodontic status: Study models Allow a more accurate assessment of some aspects of the occlusion and facilitate measurement. Models provide a good baseline record, aid the explanation of any problem to both the patient and parent, and can be used for PAR assessment. Diagnostic set-ups, where the http://dentalebooks.com O rt h odontics • 403 teeth are repositioned on the model to simulate treatment, may be helpful for consent and to assess tooth fit. Radiographs Radiographs, if justified, should only be taken after a clinical exami­ nation has been carried out. A panoramic-type view is often appro­ priate, although this may need to be supplemented by other views where indicated, e.g. history of incisor trauma, localization of unerupted teeth. A lateral cephalometric radiograph may be required in certain cases. As with the clinical examination, radiographs should be examined in a standard, structured manner and be reported upon (see Chapter 8). Having completed the examination, a precise summary of the patient’s condition should be recorded within the case notes. Cephalometrics Cephalometrics This is the measurement and study of the dental, skeletal and soft tissue relationships of the craniofacial complex on skull radiographs taken in a standardized manner. Serial radiographs can also be analysed to determine growth and treatment changes using regional superimposition. A lateral cephalometric radiograph is taken under standardized conditions in order that measurements can be compared between patients and between films of the same patient taken on different occasions. The head is held in a cephalostat so that there is a fixed constant relationship between the head, film and X-ray source. In addition to clinical examination, analysis of a lateral cephalo­ graph permits a more detailed evaluation of facial and dentoskeletal structures to aid diagnosis and treatment planning, especially in cases with a skeletal discrepancy. It also provides baseline measure­ ments to monitor the effects of growth and treatment. A lateral cephalograph is not needed, or justified, for all orthodontic assessments. Analysis of a lateral cephalograph An outline should be traced as in Figure 15.3. The following defini­ tions are important: • • Sella (S) – midpoint of sella turcica Nasion (N) – most anterior point on the frontonasal suture http://dentalebooks.com 404 • • • • • • • • • • • • C L I N I C A L D E N T I S T RY A-point (A) – deepest point on the maxillary profile between the anterior nasal spine and the alveolar crest B-point (B) – deepest point on the concavity of the mandibular profile between the alveolar crest and the point of the chin Posterior nasal spine (PNS) – tip of the posterior nasal spine Anterior nasal spine (ANS) – point of the bony nasal spine Gonion (Go) – most posterior, inferior point on the angle of the mandible Menton (Me) – lowermost point of the mandibular symphysis Pogonion (Pog) – most anterior point on the bony chin Porion (Po) – highest point on the bony external acoustic meatus Orbitale (Or) – most inferior point on the margin of the orbit Articulare (Ar) – point of intersection of the projection of the surface of the condylar neck and the inferior surface of the basiocciput Basion (Ba) – most posterior inferior point in the midline on the basiocciput. From these points a number of planes can be constructed: Frankfort plane. Po–Or. It was once believed this plane was horizon­ tal when the head was held in the natural head position, though this is not always the case. Facial plane. N–Pog. Indicates the general orientation of the facial profile. Maxillary plane. ANS–PNS. Indicates the orientation of the palate. Mandibular plane. Go–Me. Indicates the orientation of the mandible. Occlusal plane. Variety of definitions used. Functional occlusal plane (FOP) is a line following the occlusion of the molar and premo­ lar teeth. Cephalometric measurements should be interpreted with caution as there are errors in the technique. If the clinical and cephalometric findings are contradictory, more credibility should be given to the clinical findings. Cephalometric analysis tends to utilize angular values which change little with either sex or age. A vast array of measurements have been suggested; the more common are listed in Table 15.1. The anterior-posterior skeletal discrepancy is determined using angle ANB (Table 15.2). The vertical skeletal discrepancy is evaluated using the Max/Man plane angle. As the discrepancy in either increases, so do the difficulties in dealing with the problem. As well as skeletal relationships, a cephalograph can also be used to determine incisor inclination. This permits judgements to be made as to the potential for inclination changes to correct incisor position, http://dentalebooks.com • O rt h odontics 405 TABLE 15.1 Mean cephalometric values (White Caucasian norms) Mean Range (+ or −) SNA 81° 3 SNB 79° 3 ANB 3° 3 27° 4 108° 6 Maxillary-mandibular planes angle Upper incisor/maxillary plane Lower incisor/mandibular plane 92° 6 Upper incisor/lower incisor 133° 10 2 Lower incisor/A–Pog 0 mm Upper lip/aesthetic plane −4 to −6 mm Lower lip/aesthetic plane −2 to −4 mm TABLE 15.2 Relationship of ANB angle to skeletal pattern Angle ANB (degrees) Skeletal pattern 2–4 1 >4 II <2 III the need for bodily movement, and the likelihood of successful cam­ ouflage treatment. Principles of treatment planning Treatment planning is affected by many factors. In most instances the GDP should obtain a specialist opinion. Aims of treatment The aim of treatment is to produce an occlusion that is stable, func­ tional and acceptable in appearance. Treatment should only be con­ sidered in those with high motivation and excellent dental health. Considerations Space requirements. It is usual to plan the lower arch first. The form (or shape) of the lower arch is usually accepted and the position of the lower labial segment labiolingually is altered only in specific cir­ cumstances. If the lower labial segment is crowded the lower canines need to be repositioned and extractions may be needed to facilitate http://dentalebooks.com 406 • C L I N I C A L D E N T I S T RY this. Next, the upper arch should be planned around the lower arch and the upper canine placed in a Class I relationship with the lower. If the canines are placed into a Class I relationship the incisors and molars should automatically fall into ideal occlusion in the majority of patients. Tooth movement. The type of tooth movement required will deter­ mine the type of appliance to be used. Removable appliances are more suitable for tipping movement and fixed appliances can achieve bodily movement and correct multiple teeth simultaneously. Anchorage demands. Anchorage is the resistance to unwanted tooth movement in all three planes of space. The anchorage require­ ments can be assessed by undertaking a comprehensive space analy­ sis. A common scenario for anterior-posterior anchorage management is to ensure that there is adequate space for incisor retraction in Class II management. Often the maxillary first molar needs to be prevented from moving forwards to maintain space for incisor retraction. Anchorage should also be considered in the vertical and transverse dimensions. Retention. It is important that as part of informed consent, patients understand that orthodontic retention is an intergral and long-term component of orthodontic treatment. All patients have to wear their retainers, at least part-time, indefinitely, to guarantee tooth alignment. Treatment options A number of treatment options may be available: No appliance. It may be that, following the provision of space, spon­ taneous tooth movement will occur, e.g. extraction of first premolars will allow mesially inclined canines to tip distally and give some relief of crowding in the labial segment. Removable appliances. These can be used only if simple tooth tipping alone is required. Fixed appliances. Indicated where bodily tooth movement and mul­ tiple teeth need to be moved. Functional appliances. Functional appliances posture the mandible forwards to exert forces on the teeth that produce tooth movement and a small acceleration in mandibular growth. They are most com­ monly used in moderate-severe Class II cases to correct a large overjet. Treatment can often be commenced in the late mixed dentition stage and is completed with a phase of fixed appliance alignment. Orthognathic surgery. If there is a significant skeletal discrepancy, successful treatment may be beyond the scope of orthodontic http://dentalebooks.com O rt h odontics • 407 treatment alone and require a combined orthodontic/surgical approach. This type of treatment is not usually undertaken until the late teenage years, when growth has reduced to adult levels. The prospective patient must be fully aware of the treatment plan, goals and necessary implications for him/her in terms of extractions, appliances, retention and cooperation. Management of the developing dentition The development of the dentition and the timing of tooth formation and eruption is discussed in Chapter 3. It is more important to under­ stand the sequence of normal dental eruption (e.g. maxillary central incisors before lateral incisors) than the actual chronological ages, as there is individual variation in the latter. As part of the routine examination of children, the dentition should be assessed using the MOCDO convention as per the DHC of the IOTN described on page 397. This will permit referral of appropri­ ate cases for orthodontic treatment/advice. Primary dentition Natal teeth are teeth present at or shortly after birth. They are rare and most commonly found in the lower incisor region. They should be extracted only if they cause problems, such as feeding difficulty. Lack of space between anterior deciduous teeth just before they are shed is indicative of future crowding within the permanent dentition. Orthodontic treatment is rarely indicated during the primary den­ tition stage of development. The most important consideration is maintenance of oral health and stopping digit sucking habits before the permanent central incisor teeth erupt. Early loss of deciduous teeth. There are varying opinions on the management of enforced extractions. The effect of loss of a primary tooth depends upon the age of loss, the tooth lost and the degree of inherent crowding. Early loss may result in mesial migration of posterior teeth and spreading out of crowded anterior teeth. Specifically: Early loss of deciduous incisors. Usually causes no problem; do not balance or compensate. Early loss of deciduous canines. Rarely lost through caries but may be pushed out prematurely by a permanent lateral incisor if crowded. A balancing extraction, involving extraction of the contralateral http://dentalebooks.com 408 • C L I N I C A L D E N T I S T RY primary canine, can be considered to minimize any change in the centreline. Such extractions can allow some relief in anterior crowd­ ing; however, they may result in greater crowding, with mesial move­ ment of the posterior teeth, within the canine/premolar region when these teeth erupt. Early loss of primary molars. Space loss may occur due to extraction or unrestored cavities or poor restorations. The earlier the extraction the greater the space loss. Early loss of first primary molars. Unilateral loss may cause a cen­ treline shift. The first permanent molar and second primary molar will drift forwards leading to some space loss. Early loss of second primary molars. If lost before the first permanent molar erupts, there will be significant space loss especially within the upper arch. If lost after the first permanent molar erupts, con­ sideration should be given to placing a space maintainer, particularly if there is more than 6 months until the second premolar will erupt. Space maintenance, balancing and compensatory extractions The natural tooth is the ideal space maintainer. Children with high caries experience are seldom suitable candidates for long-term appli­ ance wear. If only one tooth is a significant problem then consider pulp therapy. Consideration should be given to compensating or balancing extractions. Balancing extraction. (same arch, opposite side), to maintain sym­ metry and centreline relationships. Compensating extraction. (same side, opposite arch) to maintain inter-arch relationship. It is crucial that before extracting teeth for orthodontic purposes, radiographs are taken to determine the presence/absence and condi­ tion of all teeth. Mixed dentition A variety of problems may present. Abnormalities of tooth number, form, position and structure may affect how the dentition develops as discussed in Chapter 3. Other factors affecting development of the dentition include: Sucking habits. Possible effects include: upper incisor proclination; lower incisor retroclination; narrowing of the upper arch, which may lead to mandibular displacement and a crossbite; anterior open bite (often asymmetrical). http://dentalebooks.com O rt h odontics • 409 Such habits often stop spontaneously but should be encouraged to stop before the permanent central incisors erupt. The sooner the habit is stopped, the better the chance of spontaneous improvement of any associated problems. In some situations a habit deterrent appliance may be indicated. Non-palpable maxillary canines. In most patients the maxillary canines should be palpable in the buccal sulcus at the age of 9 years. If they cannot be palpated the patient should be referred to a special­ ist. The position of the canines can be verified radiographically (using parallax) and if they are palatal consideration may be given to removal of the primary canine to facilitate spontaneous improve­ ment in position. Traumatic loss of upper central incisor. If reimplantation is not fea­ sible, initially space maintenance should be carried out and then plan long-term management. Incisors in crossbite. If corrected as early as possible, and any associ­ ated mandibular displacement is eliminated, the risk of gingival damage and tooth wear is reduced. Often the upper incisor(s) can be proclined with an upper removable appliance to remove the occlusal interference leading to the mandibular displacement. Once cor­ rected, assuming there is a positive overbite, correction should be stable at least in the short term. Treatment of posterior crossbite. Generally, a posterior unilateral crossbite, with a mandibular displacement on closure, should be cor­ rected within the mixed dentition. Often, a simple upper removable appliance with midline expansion can be used. Skeletal problems. Any patient with a severe skeletal discrepancy should be sent for an early specialist assessment. Some forms of dis­ crepancy will respond better than others to early treatment and the benefits, or otherwise, should be determined. First permanent molars of poor prognosis. The prognosis for first permanent molars should be assessed at the age of 8–9 years and if there is doubt about the long-term outlook, a specialist opinion should be sought. Often the tooth condition and dental motivation will outweigh all other factors. For the best spontaneous improve­ ment, timing is critical in the lower arch and loss of first molars is usually best when the furcation of the second permanent molar is just calcifying. If crowding is present, particularly in the premolar region, this will also help spontaneous space closure. Early loss of an upper first permanent molar can lead to rapid space loss. Con­ sideration needs to be given to balancing and compensating extractions. http://dentalebooks.com 410 • C L I N I C A L D E N T I S T RY Class I malocclusion Lower incisor edges occlude with or lie below the cingulum plateau of the upper central incisors. Problems that may be encountered in Class I malocclusions include crowding, spacing (much less commonly), crossbite, open bite, impactions and bimaxillary proclination. Crowding Cause. Disproportion between tooth and arch size and/or early loss of primary molars. Dental health. Dental health impact is not as great as once thought. In general it is easier to improve tooth brushing than to align the teeth to facilitate this. Crowding causing tooth impaction may impact upon dental health by causing root resorption. Stability. Influenced by method of correction. Treatment options. Arch expansion – achieved by increasing the arch width, incisor proclination or distal molar movement; Extrac­ tion of teeth – particularly in severe cases. Increase in lower incisor crowding in the mid- to late teens is common. Rarely poses any threat to long-term dental health and careful thought should be given before undertaking treatment as it will often involve fixed appliances and stability is not guaranteed. Spacing Cause. Often due to missing teeth, microdontia and/or dentoalveolar disproportion. Can be small teeth in average arches or normal teeth in large arches. In adults, spacing may occur secondary to loss of periodontal support and tooth drifting. Dental health. Usually there is no adverse influence on dental health; aesthetics depends on severity. Stability. The stability of space closure is poor and requires perma­ nent retention as there is a great tendency to relapse. Transverse problems – crossbites Crossbite. Deviation from the normal buccolingual relationship. Can be local or segmental. Local crossbites. Usually caused by crowding, e.g. lower second premolar forced to erupt lingually. Segmental crossbites. Involve most teeth in a buccal segment. From the dental health standpoint, of greater importance is whether or not http://dentalebooks.com O rt h odontics • 411 there is an associated mandibular displacement on closure. There are three commonly presenting patterns of crossbite: Unilateral crossbite with associated displacement Cause. Often due to mismatch in the arch widths and displacement into a position of maximum intercuspation resulting in a crossbite. Can be related to a thumb-sucking habit. Dental health. A mandibular displacement may be associated with temporomandibular joint dysfunction, faceting, and the develop­ ment of the dentition into the displaced position. Consider intercep­ tive treatment using an upper removable appliance for midline expansion. Unilateral crossbite with no displacement Cause. Often a skeletal asymmetry. Dental health. Often none, if no mandibular displacement, and treat­ ment seldom indicated. Bilateral crossbite Cause. Skeletal transverse). base problem (both anterior/posterior and Dental health. Usually there is no displacement and it is unlikely to affect appearance. Often accept as treatment stability doubtful. Some advocate rapid maxillary expansion. Vertical problems – open bite Anterior open bite (AOB). In occlusion, the incisors fail to contact and do not overlap in the vertical plane. May be due to digit-sucking habits, a skeletal discrepancy (e.g. increased vertical dimension), or anterior tongue posture. Frequently there is an associated tongue thrust which is usually secondary and adaptive. If associated with a digit habit it will improve, if all other factors are favourable, once the habit has ceased, although this is slow and may not be complete. Correction of an open bite due to a skeletal discrepancy almost always requires a combination of orthodontics and orthognathic surgery. Posterior open bite. Rare. Aetiology unclear and treatment stability often poor. Bimaxillary proclination If this is present in a Class I relationship, the upper incisors cannot be retracted without first retracting the lower incisors. Long-term stability is problematic if the lower incisor anteriorposterior position is altered, due to disruption of the soft tissue equilibrium. http://dentalebooks.com 412 • C L I N I C A L D E N T I S T RY Class II Division 1 malocclusion Lower incisor edges lie posterior to the cingulum plateau of the upper central incisors, overjet is increased, upper incisors may be proclined or of average inclination. Occlusal features Overjet. The upper incisors are often proclined (digit habit, lip trap). Where upper incisors are at a more average inclination, the increased overjet is associated with a skeletal II pattern or retroclined lower incisors (due to lower lip activity, habit, lip trap). Overbite. Variable, often deep and complete. Buccal segments. Often Class II (related to the skeletal pattern). Alignment. Crowding, spacing, etc. are all possible in addition to the arch malrelationship. Skeletal features Anterior/posterior. Usually Class II skeletal pattern due to mandibu­ lar retrognathia – the primary aetiological feature. As the severity of skeletal pattern increases, so does treatment difficulty. Vertical. Overbite will often reflect the vertical skeletal dimension although not in every case. Soft tissues Lips are often incompetent. For reasons of stability, the lower lip should lie in front of the upper incisors at rest following treatment. Mandibular position/path of closure May tend to posture the mandible to improve profile and lip contact. Why treat? If an increased overjet is present, the incisors are at greater risk of trauma. Incompetent lips may increase this risk further. The patient may also express aesthetic concerns related to upper incisor protru­ sion. Occasionally there may be an overbite problem. Treatment options Management of the overjet is the key factor in treatment planning. No treatment. May be acceptable, especially if mild. Extractions only. Rarely an option. May relieve crowding but no beneficial effect on the incisor relationship. http://dentalebooks.com O rt h odontics • 413 Removable appliances. Historically a common approach but now rarely undertaken. Two-arch fixed appliances. Frequently the most appropriate treat­ ment option. Gives the ability to deal with the overjet, overbite, as well as tooth alignment. The overjet is often largely reduced by upper incisor retraction which has a space requirement. Anchorage man­ agement is often critical for success of treatment. Functional appliance. A good option in patients with a large overjet (>6 mm) to reduce the anchorage requirements of subsequent fixed appliance treatment. Often needs a second phase of treatment with fixed appliances to complete treatment. If successful, functional appliance treatment may reduce the complexity/difficulty of secondphase fixed treatment. Orthognathic surgery. With a severe skeletal pattern, orthodontic treatment can only produce dentoalveolar camouflage. A combina­ tion of orthodontics and surgery allows the skeletal pattern to be corrected (Chapter 14). Key factors in treatment planning. Severity of skeletal pattern: can the malocclusion be treated by orthodontic camouflage or would this have an adverse effect on the facial profile? Post-treatment stability Control of the upper incisors by the lower lip is of paramount importance for stability. Class II Division 2 malocclusion The lower incisor edges lie posterior to the cingulum plateau of the upper central incisors. The upper central incisors are retroclined, the overjet is usually reduced but can be increased and the overbite is increased. Occlusal features Overjet. Typically minimal but can be increased. Upper central inci­ sors are retroclined. Upper lateral incisors are often proclined, mesially inclined and mesiolabially rotated. Lower incisors are often retroclined, contributing to lower incisor crowding, increased over­ bite and a poor interincisal angle. Overbite. Usually increased and can be sufficiently severe to produce a traumatic bite. Buccal segments. May present with a scissors bite. http://dentalebooks.com 414 • C L I N I C A L D E N T I S T RY Alignment. Variable, there is often a typical arrangement of upper lateral incisors and the incisor retroclination may be associated with crowding. Skeletal features Anterior/posterior. Often skeletal Class I pattern or mild Class II with a reduced lower anterior facial height leading to a high lower lip line. Tendency to bimaxillary retroclination. Vertical. Usually reduced or average. May have a closing (anticlock­ wise or forward) growth rotation. Transverse. If severe, results in scissors bite. Scissors bite Lingual crossbite of the lower posterior teeth. Soft tissues The lower lip often rests high on the upper central incisor (high lip line) and the labiomental fold is often deep. Mandibular position/path of closure Usually a simple hinge closure but in severe cases a habitual down­ wards and forwards posture may be seen. Why treat? Possibility of overbite trauma; aesthetics. Treatment options No treatment. Especially in a mild case this is often a very sensible option. Extractions only. Rarely an acceptable option. Removable appliance. Rarely appropriate because of the interinci­ sor relationship. May, however, use a removable appliance in con­ junction with fixed appliance treatment to help overbite reduction by taking advantage of the bite plane effect. Two-arch fixed. The vast majority of cases in this group, if treated, need upper and lower fixed appliances. This allows overbite control and, more particularly, control of the incisor inclinations – essential for long-term stability. If the incisors are retroclined it may be that the crowding can be dealt with by proclining the labial segments. This facilitates relief of crowding, overbite reduction, correction of the interincisal angle, improves the profile and may help stability. Functional appliances. An option, but must first convert the incisor relationship to Class II division 1 by upper incisor proclination. Has http://dentalebooks.com O rt h odontics • 415 added advantage of dealing with the overbite using the bite plane effect. Likely to need fixed appliances for completion. Orthognathic surgery. May need to consider in an adult with a sig­ nificant anterior/posterior discrepancy or very reduced lower facial height. Indicated if profile poor or to reduce a very deep overbite within a non-growing patient. Post-treatment stability The rotated lateral incisors have a strong tendency to relapse. Over­ bite reduction stability is related to the interincisal angle achieved at the end of treatment. Class III malocclusion Lower incisor edges lie anterior to the cingulum plateau of the upper central incisors. The overjet is reduced or reversed. Occlusal features Overjet. Often see dentoalveolar compensation of the incisors, which makes the reverse overjet seem less severe than the underlying skeletal discrepency. The upper incisors are often crowded and pro­ clined. The lower incisors are frequently retroclined (to compensate for the skeletal pattern). There may be an anterior displacement on closure. Overbite. Varies considerably. Buccal segments. Upper arch is often crowded, especially if there has been early loss of deciduous molars. Lower arch is often spaced. Crossbites are common due to a discrepancy in arch width and the lower arch being positioned relatively more anterior in a Class III malocclusion. Alignment. Upper often crowded. Skeletal features Anterior/posterior. Often the most important factor in producing a Class III is unfavourable anterior-posterior skeletal growth. As the skeletal pattern gets more adverse so does the Class III malocclusion and the scope for successful orthodontic treatment alone. The skeletal pattern is associated with a variety of causes, e.g. retrognathic maxilla, prognathic mandible, forward position of glenoid fossa, short anterior cranial base. Usually results from a combination of these factors. Vertical. Wide variation. Anterior height of the intermaxillary space may be large and associated with an anterior open bite. http://dentalebooks.com 416 • C L I N I C A L D E N T I S T RY Transverse. In many cases the maxillary base is narrow and the mandibular base wide. This is further aggravated by the anterior/ posterior discrepancy. Soft tissues Increased anterior intermaxillary height may result in incompetent lips. Mandibular position/path of closure Usually a simple hinge closure but an anterior mandibular displace­ ment may be seen if there is an incisor interference. Occasionally overclosure is evident. In a Class III malocclusion growth is often a problem. The mandi­ ble often grows for longer than the maxilla making the Class III problem worse. Vertical growth and the extent of overbite is impor­ tant for the stability of incisor correction. Why treat? There may be functional concerns about the ability to masticate, as well as aesthetic concerns. A mandibular displacement may increase the risk of temporomandibular joint dysfunction, incisal wear and/ or recession labial to the lower incisors. Treatment Key factors in treatment planning. Concerns of patient (profile or teeth), severity of skeletal pattern (and possible growth changes). Can the patient achieve edge-to-edge incisor contact? Is there an overbite which would help to retain the correction. Amount of den­ toalveolar compensation possible? No treatment. If crowding is minimal or there is no mandibular displacement, it is possible to accept and review at a later date. Extractions only. Upper arch extractions would only provide relief of crowding and not correction of the incisor relationship. Removable appliance. May be used as an interceptive measure to correct an anterior crossbite in the mixed dentition but requires an adequate overbite to maintain the correction. Single-arch fixed. Could align the upper arch and accept the Class III incisor relationship. Two-arch fixed. Will allow dentoalveolar correction of the malocclu­ sion by upper incisor proclination and lower incisor retroclination. Requires careful consideration of the effects of unfavourable growth. May wish to delay treatment until the likely outcome of growth is more predictable. Best results are obtained where the skeletal http://dentalebooks.com O rt h odontics • 417 discrepancy is mild and where there is minimal dentoalveolar com­ pensation already present. Functional appliances and protraction headgear. Less popular in Class III cases due to the undesirable effects of continuing growth. Protraction headgear may be appropriate in certain circumstances to encourage maxillary growth, proclination of the maxillary incisors, retroclination of the mandibular incisors and downwards and back­ wards rotation of the mandible. Compliance may be problematic. Orthognathic surgery. The main option for the severe Class III malocclusion. A phase of presurgical orthodontics will be needed to decompensate and align the arches before surgery in the late teens. Post-treatment stability Dependent upon the overbite and long-term mandibular growth. Removable appliances An orthodontic device which can be removed from the mouth by the patient for cleaning and eating. May be either passive or active: Active Designed to achieve tooth movement (tipping) by means of active components such as wire springs and screws. Passive Appliances designed to maintain teeth in their present position, e.g. space maintainers, retainers. This section deals with the conventional type of removable appliance used when simple tooth tipping is indicated. Most functional appli­ ances are also classified as removable appliances. Indications Use of removable appliances requires careful case selection. They should not be used in circumstances where fixed appliance therapy would be more appropriate. They may be used as an adjunct to fixed appliance treatment. Treatment options with removable appliances Simple tipping movement of teeth. A force applied to the crown of a tooth by a spring will cause tipping about a fulcrum roughly onethird to one-half of the way from the root apex. As the crown tips in one direction the root apex will tip in the opposite. If the use of a removable appliance to tip a tooth is being considered, assess the angulation of the tooth, its desired position and decide if it is feasible to achieve this movement with simple tooth tipping. http://dentalebooks.com 418 • C L I N I C A L D E N T I S T RY Overbite reduction. In cases with a deep overbite, the use of a flat anterior bite plane may help overbite reduction by holding the poste­ rior teeth out of occlusion and allowing their continued eruption. Elimination of occlusal interferences and crossbite correction. Pos­ terior bite planes can be used to prop the occlusion and facilitate crossbite correction by freeing the occlusion and eliminating any displacement on closure. Extrusion of teeth. (if used with a fixed appliance component) A spring can be used to apply an extrusive force if a bracket is placed to allow force delivery. The acrylic coverage of the palate provides verti­ cal anchorage to resist the effect of this extrusive force. Space maintainer. A removable appliance can be used to control the position of groups of teeth while awaiting further eruption. Retainer. Removable retainers are often used after active appliance treatment. Habit deterrent. A simple removable appliance may be used, where appropriate, to help discourage a digit-sucking habit. Contraindications Removable appliances are not indicated if simple tooth tipping is inappropriate, e.g. where multiple rotations or bodily tooth move­ ment is required. The range of malocclusions that can be treated to a high standard with removable appliances alone is limited. Remov­ able appliances should be avoided in poorly controlled epileptic patients due to the risk of appliance inhalation during seizures. Components of removable appliances These can be described as: retentive components; active components; baseplate. Retentive components Retention is the method by which the appliance resists displacement away from the oral mucosa. Good retention will help patient compli­ ance, anchorage and tooth movement. Typical retentive components are: Adams’ clasp Posterior teeth – 0.7 mm hard stainless steel wire. Southend clasp Anterior teeth – 0.7 mm hard stainless steel wire. Retention is gained by engaging the undercuts of teeth. In appli­ ance design the principle of three-point (or more) fixation should be adhered to. Active components Provide the force which moves the teeth. A variety of different methods are used, e.g. wire springs and bows, screws, elastics. http://dentalebooks.com O rt h odontics • 419 Springs. Springs are activated in the intended direction of move­ ment and when the appliance is seated the spring is displaced. The spring then attempts to return to its original position, thereby apply­ ing force to the tooth. The force applied (F) is affected by the deflection of the wire (d), radius of the wire (r) and length of the wire (l), This is expressed in the equation: F∝ dr 4 l3 Examples: palatal finger spring, buccal canine retractor, Z-spring. Points to remember Stability ratio – ideally a spring should be flexible in the desired direc­ tion of action but not in others. As light a force as possible for a given deflection is desired. Coils are incorporated to increase the length within the confines of the oral cavity. The coil should unwind as the force is dissipated. Although simple in design, to be used to maximum effect careful attention to detail is needed. If poorly designed or adjusted they can cause tooth movement in the wrong direction. The force applied to a single-rooted tooth should be about 0.3 N (approx. 30 g), which, for a 0.5 mm palatal finger spring, will be about 2–3 mm of activation. A palatal finger spring should be boxed and guarded. Bows. Mechanically more complex than springs. Supported bows such as a Roberts’ retractor have good flexibility and a good stability ratio. Screws. Typical activation (one turn once or twice a week) is 0.2 mm and thus a large force is applied intermittently over a small distance. Elastics. Historically used as an alternative to a labial bow to improve the appearance, but may slide up teeth and traumatize the soft tissues. Furthermore, they tend to flatten the arch. Baseplate Removable appliances have an acrylic baseplate. It should fit well around the teeth that are not to move and is trimmed away from those required to move. The functions of the baseplate are: to support and protect other components; to prevent unwanted drift of teeth; to contribute to anchorage. May be extended into bite planes. Flat anterior bite plane. Often used to free the occlusion or to encourage overbite reduction. At design stage, the height and length of the bite plane must be specified. http://dentalebooks.com 420 • C L I N I C A L D E N T I S T RY Posterior bite plane. Can be helpful in eliminating a displacement and to free the occlusion sufficiently to push a tooth over the bite. Keep to minimal thickness. The baseplate also has an important role in anchorage (p. 399). Anchorage can be: Intramaxillary from within the same arch. Intermaxillary from the opposing arch. Extraoral from outside the mouth (headgear, facemask). With a removable appliance anchorage is aided by: baseplate contact with teeth not being moved; baseplate contact with the palate; applying simple tipping forces; applying light tooth-moving forces; applying force to only a small number of teeth at any one time. Anchorage can be reinforced by use of extraoral (headgear) or intermaxillary (elastic) anchorage. Designing a removable appliance When designing a removable appliance remember: design for a spe­ cific task; design at the chair side with the patient still in the chair; draw and describe the design on a laboratory prescription sheet; use a systematic approach: retention – activation – baseplate and any baseplate modifications; do not attempt to put too many active com­ ponents on one appliance. Appliance fitting When fitting a removable appliance: 1. Check the appliance provided complies with the design and there are no sharp spicules of acrylic. 2. Try the appliance in the mouth. 3. Ensure it is comfortable. 4. Adjust the appliance. 5. Take relevant measurements to assess progress. 6. Give patient instructions on: a. insertion, removal and care b. when to wear c. what to expect d. what to do if problems occur. 7. Arrange next visit – usually 4–6 weeks later. Appliance check visits At each visit assess: tooth movement; anchorage; cooperation. A standard approach is essential at each visit to allow this informa­ tion to be gathered quickly and efficiently. http://dentalebooks.com O rt h odontics • 421 1. Ask the patient how he/she is coping. This will identify any specific problems and allows an assessment of speech. 2. Examine the patient with the appliance in situ. Does it fit? Are the active components seating correctly? Are the teeth still free to move? 3. Ask the patient to remove the appliance. How does the patient handle the appliance? Does it look worn? 4. Check measurements – progress of tooth movement and anchorage. 5. Adjust appliance: retention active components baseplate. 6. Check insertion and removal. 7. Revise instructions to patient. 8. Review in 4 weeks. – – – Problems with removable appliance treatment Potential problems are: no tooth movement; incorrect tooth move­ ment; anchorage loss. If treatment progress is slow, identify a cause as soon as possible. No tooth movement Check at each visit – if teeth fail to move as expected check: Is the tooth free to move? Baseplate trimmed correctly; occlusal locking; retained root/other anatomical limitation. Active components adjusted correctly? Check screw turns; check springs correctly in place; springs activated at last visit. Lack of wear? Signs of non-wear are: missed appointments; broken appliances; poor speech with appliance in situ; poor fit; still active at each visit; no signs of wear on appliance/soft tissue; patient displays difficulty inserting or removing appliance. Incorrect tooth movement Check: appliance design; position of coils; contact of active compo­ nent with tooth. Anchorage loss Signs (if retracting a tooth). An increasing overjet; developing cross­ bite in buccal segments; deterioration in buccal segment relationship. Action. Reduce active component force; check appliance fit, design and wear; seek further advice from a specialist orthodontist if necessary. http://dentalebooks.com 422 • C L I N I C A L D E N T I S T RY Advantages of removable appliances Tip teeth efficiently; good for overbite reduction; bite planes can elimi­ nate displacements/occlusal interference; tooth movements usually few and simple; less chair side time needed than with fixed appli­ ances; fewer inventory problems than with fixed appliances; can remove for cleaning; good source of anchorage from baseplate. Disadvantages of removable appliances Limited tooth movement available; limited scope in lower arch; affect speech; removable by the patient – poor compliance. Fixed appliances An orthodontic device in which attachments are fixed to the teeth and forces are applied by archwires or auxiliaries via these attachments. Components Classified as attachments (brackets or bands), archwires and auxiliaries. Attachments Act as a ‘handle’ to allow the application of forces to the teeth in three dimensions. Two types: Brackets. Fixed to the tooth by bonding and are used on most teeth. Bands. Cemented to the teeth; used on molars and teeth with persist­ ent bracket failures. The most commonly used type of fixed appliance is the preadjusted edgewise appliance (also termed the Straight wire appliance). A number of different bracket systems are available on the market and differences include the material used for construction (e.g. stain­ less steel, ceramic), the in-built values or prescription (e.g. Roth, Andrews, MBT) and the method of archwire ligation (e.g. selfligation). Some manufacturers have claimed that their brackets speed up treatment but there is no evidence to suggest that these claims are true. Archwires The archwire is tied to the attachments. In the early stages of treat­ ment (aligning and levelling) the archwire is active. At engagement, the wire is deflected and pulls the teeth with it as it returns to its original shape. In the later stages of treatment the archwire is passive and the teeth are moved along the archwire by auxiliary forces. http://dentalebooks.com O rt h odontics • 423 Auxiliaries Springs or elastics. Used to apply force to the teeth. Indications for fixed appliances Fixed appliances are indicated where multiple tooth movement is required, e.g. de-rotation, bodily movement, controlled space closure at extraction sites. They require a suitably trained operator and suit­ ably motivated patient – excellent oral hygiene, caries controlled, desires treatment and understands the implications, i.e. 18–24 months duration, visits 4–8-weekly, brush teeth after every meal, fluoride mouthwash daily, modify diet, wear elastics/headgear if required, some discomfort, retainers at end of treatment. Even then, relapse may sometimes occur. To achieve the highest standard of care, fixed appliances are usually indicated. They are, however, demanding of patient coopera­ tion. Treatment should be undertaken only when the patient fully understands the implications. If in doubt, delay and do not treat – choosing a simple compromise option may preclude full correction at a later date. Contraindications for fixed appliances Poorly motivated patient; poor dental health; operator without appropriate training in use of fixed appliances; some malocclusions may not be amenable to fixed appliance treatment, i.e. beyond the scope of orthodontics alone. Advantages of fixed appliances Precise tooth control possible; multiple tooth movements can be made concurrently. Disadvantages of fixed appliances Aesthetics; oral hygiene requirements; demanding in terms of mate­ rials and operator time; breakages; anchorage control/treatment monitoring more difficult. Functional appliances The term functional appliance describes those appliances which engage both arches and act principally by holding the mandible away from its normal resting position, and utilize the forces of the circumoral musculature to move the teeth. http://dentalebooks.com 424 • C L I N I C A L D E N T I S T RY Classification There is no universally accepted method of classification. Most are named after their originator, e.g. Andresen, Bionator, Harvold, Frankel appliances, Clark Twin–Block. Mode of action Most functional appliances act by utilizing one or more of the follow­ ing: a forced mandibular posture, which transmits forces to the teeth and jaws; a screening effect, which can either use or relieve direct forces on the teeth from the circumoral soft tissues; bite planes which produce differential eruption. Case selection Can be used for different types of malocclusion but most effective in Class II division 1 cases. For success, virtually full-time wear is needed. It is important to review progress carefully after 6 months and if treatment is not proceeding satisfactorily, an alternative approach should be considered. Functional appliances may be used for definitive treatment or as Phase 1 of two-phase treatment: e.g. Phase 1 to reduce the overjet, overbite and improve the sagittal arch relationship; Phase 2 to com­ plete alignment using fixed appliances. Advantages of functional appliances May utilize growth potential; can start treatment in the mixed denti­ tion; effective vertical control of increased overbite; chair side adjust­ ment time is minimal. Disadvantages of functional appliances Precise tooth movement not possible; very dependent on patient cooperation; often need Phase 2 treatment to complete; treatment duration is often prolonged. Orthodontic management of cleft lip and palate Cleft lip and palate (CLP) is the most common congenital deformity in the craniofacial region. There is a wide range of presentation ranging from bifid uvula to a complete bilateral cleft of lip and palate. Incidence (UK) Approximately 1 in 700 live births. Some ethnic variation. In white Caucasians: CLP is more common in males; unilateral clefts occur http://dentalebooks.com O rt h odontics • 425 more often on the left side; isolated cleft palate is more common in females. Classification Patients with cleft lip and palate can be divided into two distinct groups. Cleft lip ± cleft palate. Those with cleft lip and cleft palate (CL + CP), or those with cleft lip alone (CL). Cleft palate. Those with cleft palate alone. Aetiology Not fully understood. Certain cleft types show family history. Genetic predisposition may be triggered by an environmental factor. May occur in isolation or as part of a syndrome. Cleft lip and palate associated problems Main problems in orthodontic management are tooth malalignment, especially at cleft site, lack of bone to move teeth into, and the effect on facial growth. Dental Teeth. Lateral incisor on the cleft side may be absent, diminutive, one on each side of the cleft, hypoplastic, or displaced. Central incisors may also be involved, more commonly in bilateral cases. Occlusion. Majority of occlusal problems occur secondary to surgical repair of the defect. Postoperative scarring impedes normal growth of the maxilla in all three planes of space. A Class III incisor relation­ ship is often seen with posterior crossbites also present. Skeletal pattern/growth. Is usually a skeletal Class III relationship due to effect of surgical scarring and maxillary retrusion as growth proceeds. Palate repair has a more serious effect on growth than does lip repair alone. Differences are most noticeable at pubertal growth spurt. Facial deformity. Surgery can disguise with varying degrees of success (Chapter 14). Hearing. Prone to otitis media due to interruption of the normal function of the Eustachian tube. Speech. Problems with normal speech due to a combination of hearing problems, inadequate soft palate function, palatal morphol­ ogy and lip morphology. Psychological. Given the above, a range of psychological problems may also be present. http://dentalebooks.com 426 • C L I N I C A L D E N T I S T RY Management of cleft lip and palate problems Requires a team-based approach as part of a centralized service in a treatment centre which is exposed to large numbers of new cases per year. Main team members include orthodontist, cleft surgeon, speech and language therapist, ENT specialist. Other disciplines involved at various stages include health visitor, oral and maxillo­ facial surgeon, restorative dentist, psychologist. The GDP has an important role to play in maintaining the highest possible level of oral health. Typical stages in management 1. Neonatal/first 18 months Parental counselling and introduction to the Cleft Lip and Palate Association (CLAPA). Offer feeding advice, establish preventive regimen and routine dental care. Presurgical orthopaedics (to align the displaced cleft segments) may be used in some centres. Lip repair is carried out at about 3 months (some centres within days of birth). Palate repair is carried out at 9–18 months to facilitate feeding and speech. 2. Early mixed dentition Permanent incisors may erupt into linguoocclusion. This should be corrected if feasible but may be delayed until the next phase of development. 3. Mid-mixed dentition If an alveolar cleft is evident, secondary alveolar bone graft is routinely performed at age 9–10 years. Cancellous bone from the iliac crest is placed in the alveolar cleft and will: a. facilitate eruption of the permanent canine b. allow alignment of teeth adjacent to the cleft c. promote orthodontic rather than prosthodontic repair d. help stabilize the maxillary segments e. assist closure of fistulae f. improve vestibular anatomy. 4. Early permanent dentition Treatment indicated is dictated by the concerns of the patient and severity of the skeletal discrepancy. If skeletal discrepancy is not severe then conventional fixed appli­ ance treatment can be carried out. A significant proportion of cleft cases will have a severe skeletal Class III pattern, the full cor­ rection of which requires combined orthodontics and orthog­ nathic surgery in the late teens. 5. Late teens If orthognathic surgery is indicated, the Class III rela­ tionship is corrected by fixed appliance treatment to decompen­ sate and coordinate the dental arches prior to surgery such as a Le Fort I advancement osteotomy and a mandibu­lar set-back osteotomy. A genioplasty may also be indicated. http://dentalebooks.com O rt h odontics • 427 Orthodontic aspects of orthognathic surgery (see also Chapter 14) Orthognathic surgery is used to correct malocclusions beyond the scope of orthodontics alone, i.e. when there is a significant skeletal discrepancy. This approach to treatment is not usually carried out until growth has reduced to adult levels in the late teens. Candidates for combined orthodontic/surgical treatment must be fully assessed at a combined clinic by an orthodontist and maxillo­ facial surgeon. Treatment is highly demanding of patient coopera­ tion, and careful preoperative explanation is required. Patients may have unrealistic expectations and assessment by a clinical psycholo­ gist may be helpful. In most cases, orthodontic treatment using fixed appliances will be required both pre- and postoperatively. Aims of presurgical orthodontics General arch alignment; arch width correction; correction of anterior/posterior position of incisors; changes in overbite; correc­ tion of centrelines; create space for segmental surgery. At this stage, the aim is to facilitate surgery and create tooth posi­ tions that are likely to be stable postoperatively, rather than to obtain ‘ideal’ cuspal relationships. Fine adjustments and final tooth position are achieved postoperatively. Treatment Common problems requiring a combined orthodontic/orthognathic surgical approach include: severe skeletal Class II pattern; severe skel­ etal Class III pattern; severe anterior open bite; transverse skeletal asymmetry; congenital craniofacial deformity. http://dentalebooks.com This page intentionally left blank http://dentalebooks.com Paediatric dentistry Organizing dental treatment for children 429 Managing behaviour in children 432 Development of the dentition 434 Maintenance of the dental operating field 435 Pit and fissure sealants 437 16 Restoration of carious primary teeth 438 Pulp therapy 441 Traumatic injuries 446 Oral pathology in children 452 Children with special needs 455 Safeguarding children in dental practice 457 Paediatric dentistry Concerned with comprehensive therapeutic oral health care for children from birth through adolescence, including care for those who demonstrate intellectual, medical, physical, psychological and/or emotional problems. Organizing dental treatment for children The basic principles underlying history taking and examination described in Chapter 7 apply equally in paediatric dentistry. However, organization of treatment for children is made difficult by their lack of dental experience. A planned atraumatic introduction, using appropriate behaviour management techniques, is necessary to provide children with the appropriate skills to cope with dental treatment. This is complicated if the child first presents in pain. Many adults ascribe lifelong dental anxiety and phobias to negative experiences of dentistry in childhood. Aims of treating children • • • • Provide a positive introduction to dentistry. Provide child with the skills necessary to accept dental treatment. Institute good preventive practice. Provide any necessary restorative care in a planned and organized fashion. History May rely on parent/carer for accurate history. Should include: whether pain is present and how this presents; previous experience http://dentalebooks.com 430 • C L I N I C A L D E N T I S T RY of dental treatment – e.g. has child had local anaesthetic before, or experience of rubber dam?; medical and social history; details of oral hygiene practices, including who brushes the teeth (child or other). Examination Extraoral. Much information can be obtained from observing how the child enters the surgery, relationship with parent(s), behaviour. Intraoral. Young children (<3 years) may be best examined on a parent’s lap. Note overall condition of the mouth, oral hygiene, caries experience, evidence of previous dental treatment, occlusion/ development of the occlusion, soft tissue pathology. Radiographs should be taken only when clinically indicated (Chapter 8). Treatment planning Pain relief takes priority. In the absence of pain, a sequential, gradual approach including prevention, restorative care and planned follow-up is required. First visit. Introduction to environs of surgery. Limit to history taking, examination and, possibly, radiographs, details of oral hygiene and dietary practices. Second visit. Preventive advice, acclimatization and simple treatment, e.g. dressing open carious lesions, application of fissure sealants, polishing. Third and subsequent visits. Commence restorative care, beginning with most easily restored cavity. Introduce local anaesthesia if needed. Progress to more advanced procedures. Reinforce preventive messages. At the final visit the recall interval should be decided mainly based on the individual’s caries risk status. Preventive versus restorative care The adoption of good preventive behaviour is crucial in preventing further caries and avoiding the ‘restoration cycle’, i.e. repeated replacement of restorations. Preventive measures such as diet modification, oral hygiene instruction, prophylaxis, application of fluoride varnish, fissure sealants, etc., provide a good means of building confidence and cooperation but should not be used as an excuse to avoid dealing with decayed teeth. Choice of preventive regimen Preventive aspects of dental care are discussed in Chapters 1 and 3. While all preventive regimens have the common themes of reduction of non-milk extrinsic sugars, provision of fluoride and improved plaque control, the technique employed should be tailored to individual patient requirements. Thus, in a caries-free child, brushing http://dentalebooks.com Paediatric dentistry • 431 with a fluoride toothpaste may suffice as a means of delivering fluoride, whilst a toddler presenting with rampant or nursing bottle caries would benefit from both systemic and topical fluorides as well as specific diet advice to child and carer Chapters 1 and 3. Practical points • • • • • For maximum fluoride benefit, children should spit, not rinse, after brushing. Under 7 years, children often lack sufficient manual dexterity to brush teeth effectively. Younger children should be supervised when brushing to: • ensure effective brushing • limit amount of toothpaste swallowed. Sugar-containing foods and drinks should be kept well clear of bedtime. Keep preventive messages simple, build up gradually. Role of parents or carers Children are brought to the dentist; they do not choose to come. It is important to ensure that the adult accompanying the child is a parent, or a carer able to give consent. Parents can influence the organization of treatment in a number of ways. With a young child, the history must be obtained from a responsible adult. Additionally, parents may: • • • • • • have to organize time off work or care for other siblings in order to attend; hence need to explain: • what treatment is required • likely number of visits • need to restrict treatment on early visits in order to build child’s confidence be responsible for implementing home strategies (e.g. brushing, diet control) wish their main concerns dealt with promptly be guilty about the child’s dental disease or behaviour adversely affect the child’s behaviour because of their own anxiety about dental treatment be overly protective or demanding. There are no hard and fast rules as to whether a parent should stay with the child during treatment or remain in the waiting room. This is best judged on an individual basis, except for children under 4 years, who almost invariably benefit from having a parent present. Remember • A child’s attention span is short – plan treatment accordingly. • Call child by his/her correct name. http://dentalebooks.com 432 • • • • • • C L I N I C A L D E N T I S T RY Children are very sensitive to environment and non-verbal communication – so smile! Child-friendly environment is important – posters, toys, etc. Ensure parents understand their role in the process. Recruit skills of other members of team. A member of the surgery staff may be particularly adept at putting children at their ease. Consider referral to a colleague when failing to make progress. Managing behaviour in children An important aspect of treating children is the ability to enable them to relax in the dental setting and learn how to cope with treatment. The child’s attitude and behaviour will be influenced by many factors including: • • • • • • • age, maturity, personality attitude of parents previous dental experience previous medical experience whether (s)he has a dental problem dental staff attitude surgery environs. Various techniques for managing behaviour of children in the dental setting have been described. Whilst the terminology may be unfamiliar, most dentists routinely employ these methods when dealing with children as they are largely a matter of common sense. Remember some techniques require good verbal skills that some very young children and some children with specific disabilities may lack. Behaviour management techniques Remember non-verbal communication occurs continuously and may reinforce or contradict verbal signals. Smile! Where possible, treatment is organized progressing from simple to more complex procedures. Tell–show–do. This technique is widely used to familiarize a patient with a new procedure. The tell phase involves an age-appropriate explanation of the procedure. The show phase is used to demonstrate the procedure, for example demonstrating with a slow handpiece on a finger. The do phase is initiated with a minimum delay, in this case a polish. It is important that the language used be appropriate to the child’s age, and the whole dental team must adopt the same approach: specifically, emotive or negative words should be avoided. Enhancing control. Feeling out of control is a major cause of dental anxiety. The use of a ‘stop signal’ can give the child a degree of http://dentalebooks.com Paediatric dentistry • 433 control over the dentist. The stop signal, usually raising an arm, should be rehearsed and the dentist should respond rapidly when it is used. It is also possible to use a signal to proceed with treatment. Modelling. A child learns by watching others, e.g. siblings, other children. It is important that the patient can relate to and identify with the model and that the model exhibits appropriate behaviours. Videos or DVDs can be employed. Used for children with little or no dental experience. Behaviour shaping and positive reinforcement. Dental procedures require complex behaviours that need to be learned. For children, small clear steps leading to ideal behaviour are required. Rewarding good behaviour by paying compliments makes it possible to selectively reinforce positive behaviour, which is therefore more likely to be repeated. If possible, do not abandon treatment completely as a result of temper tantrums, etc. – this simply reinforces negative behaviour. In these circumstances attempt a compromise, e.g. dressing placed instead of final restoration, which finishes treatment session on a positive note. Stickers, badges and praise act as positive reinforcers, but the most powerful reinforcers are social stimuli such as facial expression, positive voice modulation and verbal praise. To be effective, praise must be continuous and specific. Distraction. This approach aims to shift the patient’s attention from the dental setting to some other situation, or from a potentially unpleasant procedure to some other action. Short-term distractors such as diverting the attention by gently pulling the lip as a local anaesthetic is given or having patients raise their legs to stop them gagging during radiography may also be useful. Talking to patients or telling them stories while treating them, uses the voice as a distractor. Desensitization. This technique helps individuals with specific fears or phobias overcome them by repeated contacts. A hierarchy of fearproducing stimuli is constructed, and the patient is exposed to them in an ordered manner, starting with the stimulus posing the lowest threat. In dental terms, fears are usually related to a specific procedure such as local anaesthetic. First, patients are taught to relax, and in this state exposed to each of the stimuli in the hierarchy in turn, only progressing to the next when they feel able. Friendly and caring attitude of dental staff is very important. The technique is useful for children who can clearly identify their fear and who can verbally communicate. Behaviour management techniques may not always work with extremely anxious patients. May have to resort to hypnotherapy or a pharmacological approach – sedation or general anaesthesia (Chapter 9). http://dentalebooks.com 434 • C L I N I C A L D E N T I S T RY Hypnotherapy and neuroLinguistic programming (NLP) Hypnotherapy and NLP have an increasing role to play in the management of anxious children and young people. Most paediatric dental units have staff trained in such techniques, which in addition to the behaviour management techniques described above, can help to reduce the need for resorting to the use of pharmacological agents. Development of the dentition The timing of tooth formation and eruption is variable. The order of eruption is more important than precise age. Average dates of mineralization and eruption of the teeth are recorded in Chapter 3. Development of the dentition can be divided into the following stages. Pre-teeth Usually there are no teeth until about 6 months. The upper gum pad is wider and longer than the lower. Palatal vault is almost flat, and the fraenum of upper lip is attached to the crest of the gum pad and is continuous with the incisive papilla. Occasionally children are born with teeth (natal teeth) or erupt them within a month (neonatal teeth). They are usually mandibular and mobile, having no root development. Left in situ, normal root development occurs but, if they are at risk of inhalation or interfering with feeding, they should be extracted. Development of primary dentition Timing of tooth eruption is variable (about 6 months to 24/36 months). Lower incisors usually erupt first. Primary incisors are more upright than their successors and tend to be spaced. By age 5 attrition of primary teeth is common and incisors may be edge to edge. Varying degrees of space at this stage – if no space or crowded, then crowding in the permanent dentition is likely. Mixed dentition to permanent dentition Begins with eruption of first permanent molars or lower central incisors at about age 6 years. Upper central incisors and lower lateral incisors erupt around the age of 7 years with upper lateral incisors a year later. A variation of ±1 year is within normal limits but the eruption sequence should not vary. If the upper lateral incisor erupts ahead of the central incisor, pathology should be suspected (supernumerary or dilacerated central). Permanent incisors develop slightly behind the roots of the primary incisors, and are larger than them. The extra space is gained from: • • • spacing of primary incisors permanent incisors are more proclined increases in inter-canine width at this time. http://dentalebooks.com Paediatric dentistry • 435 Lower incisors often erupt lingually and are moved forward by tongue pressure. Commonly an upper midline space is present when the upper incisors erupt and the crowns are distally inclined (it closes as lateral incisors and canines erupt). Canines move buccally and should be palpable high in the buccal sulcus from age 9 years onwards. Lower canine and first premolars begin to erupt at 10 years, followed by second premolars at age 10–12 and upper canines at 11–12. Normal pattern and symmetry of eruption is more important than chronological guidelines. A given pair of teeth normally erupt within 6 months of each other; if they fail to do so the non-eruption should be investigated. Most leeway space is taken up by the molars moving mesially. Whilst the sequence of eruption is also variable, in lower it is usually canine, first premolar, second premolar, and in the upper is usually first premolar, second premolar, canine. Second molars erupt at about 12–14. Third molar eruption is quite variable. Late changes These include an increase in lower incisor crowding and an increase in the interincisal angle. May be a slight increase in mandibular prognathism. Maintenance of the dental operating field Adequate isolation of the tooth during operative procedures is essential and can be achieved by retractors, saliva ejectors, cottonwool rolls, absorbent pads, high- and low-volume aspirators and rubber dam. Retractors. Various forms are available. Care should be taken not to traumatize soft tissues, particularly when anaesthetized. Saliva ejector. Attached to low-volume aspirator this aids patient’s comfort and reduces the need to swallow or spit out. High-volume aspirator. Essential when using high-speed handpieces (or ultrasonic scaler). Aids vision and reduces aerosol. Cotton-wool rolls. Place buccally and lingually. Of limited value in patients who produce copious saliva. Absorbent pads. Triangular in shape. Placed buccally, these are useful when fissure sealing upper molar teeth. Both cotton-wool rolls and absorbent pads should be moistened before removal to prevent adherence and damage to the oral mucosa. http://dentalebooks.com 436 • C L I N I C A L D E N T I S T RY Dental dam (Rubber dam) Provides the optimum means of isolation. (Although referred to traditionally as ‘rubber dam’, it may be better referred to as ‘dental dam’ as it is available in a latex-free formulation for patients with latex sensitivity. Advantages • • • • • • • Moisture control. Prevents salivary contamination. Particularly important during pulp therapy and acid-etch procedures. Protects airway. Prevents inhalation or ingestion of foreign bodies. Prevents contamination of materials. Controls soft tissues and aids visualization. Protects patient from potentially irritating materials such as endodontic irrigants. Be very careful to ensure no leaks under the dam. Provides physical barrier from oral fluids and reduces bacterial load of aerosols. In spite of the above advantages, dental dam has not been routinely employed in the UK, with perhaps the exception of endodontic therapy. However, with practice, dental dam can be applied easily in most situations and is generally well tolerated by patients. When operating under dental dam, be sure to check angulation of burs, etc., as it is easy to become disorientated. Technique Several techniques for application of dental dam are available depending on whether clamp is placed before, after or at the same time as the dental dam sheet. The following describes clamp placement before dental dam using a split dam technique which is most useful in the child patient. 1. Punch two holes in the dental dam about 1–2 cm apart and join the holes by cutting with scissors. 2. Select appropriate dam clamp. 3. Attach floss to the bow of the clamp. (Aids retrieval should the clamp become dislodged.) 4. Use forceps to place clamp on the most posterior tooth. Ensure it is firmly seated and not traumatizing the gingivae. 5. Stretch the slit anteriorly and place between anterior teeth (usually mesial of canine). 6. Stretch the periphery of the dental dam over a frame. 7. Rubber ‘wedjets’ may be used to anchor the dam anteriorly. http://dentalebooks.com Paediatric dentistry • 437 Dental dam can be used to isolate a single tooth or a number of teeth depending on the procedure to be undertaken. In the anterior region as an alternative to clamps, floss ligatures, rubber ‘wedjets’ or orthodontic elastics can be used to hold a dental dam. Pit and fissure sealants A resin (BIS-GMA) based material (Chapter 11) applied to pits and fissures of teeth that mechanically adheres to dental enamel, preventing bacteria and substrates from gaining further access. Sealants • • eClear (transparent) (Opaque). There is no proven difference in efficacy between clear versus opaque fissure sealant. Clear sealant potentially allows the operator to see carious changes beneath the sealant. However, this potential advantage is countered by the fact that clear sealants pick up extrinsic dietary stains which can mimic or mask carious change. Opaque sealants have the advantage of being more readily detectable at subsequent review which make it easier for the operator to determine whether there has been any sealant loss. Because of the difficulty of assessing potential microleakage and development of caries beneath sealants, irrespective of sealant type used, radiographic caries assessment should be undertaken as determined according to caries risk. Selection of patients It is not cost-effective to seal all occlusal surfaces. In selecting cases consider: Children at high caries risk. Indicated by extensive caries in primary dentition, socially disadvantaged background. Caries in a first permanent molar indicates a need to seal the remaining first molars and second molars as soon as they erupt. Children with additional modifying factors. e.g. medical, intellectual, social, developmental, behavioural or physical disability (Chapter 20). Teeth at high risk. Teeth with deep fissure or pits, e.g. lateral incisors. Sealants should be applied as soon as the whole occlusal surface has erupted and although most beneficial within 2 years of eruption, they can be completed at any time during life depending on caries risk. Only sound teeth should be sealed. Where there is any suspicion of caries, investigate with small bur and provide sealant http://dentalebooks.com 438 • C L I N I C A L D E N T I S T RY restoration. Sealants can be used as a means of managing enamel caries. Intermediate fissure sealants Where cooperation is inadequate to enable the multi-stage process of resin sealant placement, the use of low viscosity glass ionomer cement or topical fluoride varnish can be applied to the fissure system until such time (if at all) cooperation increases to allow conventional resin sealant placement. Technique for application of fissure sealant 1. Clean the tooth surface with rotary bristle brush and pumice to remove pellicle. Dental dam may help. 2. Wash, isolate and dry tooth. 3. Apply 30–50% phosphoric acid etchant for 30 seconds. Gel is easier to control than liquid. 4. Wash tooth for 15 seconds. 5. Dry tooth for 30 seconds. 6. Apply resin and cure. 7. Check resin – use probe to ensure covers entire fissure system and to remove flash. Add if deficient. 8. Check occlusion. Moisture control is crucial. Salivary contamination will reduce the etch markedly and lead to poor retention and loss of sealant. Restoration of carious primary teeth Current practice is based on the realization that a restoration, with an adequate peripheral seal, allows the carious process to arrest, even when a small amount of soft carious dentine is purposefully left in situ (indirect pulp cap). This conservative approach prevents pulpal exposure and facilitates the healing of the pulpo-dentinal complex. Therefore, the previously used and more aggressive principles of cavity design no longer apply. Primary molars Single surface cavities in first primary molars and both single- and two-surface cavities in second primary molars can normally be restored with direct plastic restorations where the cavities are not extensive. All other size/surface combinations of cavities in primary molars are optimally restored with Preformed Metal Crowns (PMCs). http://dentalebooks.com Paediatric dentistry • 439 Anterior primary teeth Composite resin is the material of choice for anterior tooth restorations. These can be placed freehand or with the use of cellulose matrix strips or crown formers following the same principles as those used in the permanent dentition. Miniature handpiece heads and small burs should be used, if available, as they allow significantly better access in the young patient. Materials (see also Chapter 11) A wide variety of restorative materials can be used to definitively restore a primary tooth. Preformed metal crowns and composite resin are the materials of choice to ensure maximum longevity and durability. In this regard, amalgam no longer confers any advantage and its continued use in the primary dentition is difficult to justify. Preformed metal crowns (PMC). Are designed to fit the anatomical (not clinical) crown margins and are thus placed subgingivally. They are the most durable restoration for primary molars. Uses: • • • • • Two surface (or more) cavities in first primary molars More than two surface cavities in second primary molars Following pulp therapy in primary molars Failure of plastic restorative technique As initial restoration in amelogenesis imperfecta, dentinogenesis imperfecta or severe enamel hypoplasia. Hall technique versus conventional preparation The conventional preparation stages prior to PMC placement involves complete caries removal (+/− pulp treatment as per Chapter 19) followed by occlusal and approximal hard tissue reduction. The Hall technique involves removing either no caries, or only the softest surface caries, prior to placement of the crown without any hard tissue tooth reduction. Separators may or may not be used prior to crown placement. The Hall technique is not simply a means of restoring coronal tooth morphology; it is also a method of conservatively managing the pulpal-dentinal complex when it retains a reparative capacity. A careful history, clinical and radiographic examination must be undertaken prior to employing this technique to ensure there are no signs or symptoms of irreversible pulpitis, pulpal necrosis or sepsis. http://dentalebooks.com 440 • C L I N I C A L D E N T I S T RY Conventional procedure: 1. Administer local anaesthesia. 2. Remove caries. 3. Select crown of appropriate size. Dividers can be used to measure mesiodistal dimension of tooth. 4. Create space to accommodate crown: a. Reduce occlusal surface by 1–1.5 mm. b. Use tapered diamond to reduce axial surfaces. Extend to level of gingival margin, do not leave a ledge. 5. Crown should ‘click’ onto preparation; the gingivae will blanch. 6. With modern PMCs, the need for crown adjustment is uncommon. Trimming with crown scissors, recontouring with crimping pliers and ­polishing margins is only normally required with very overextended margins. 7. Check occlusion. 8. Cement using glass ionomer as it adheres to tooth substance and ensures a good marginal seal. 9. Remove excess cement and re-check occlusion Hall technique procedure: 1. If separators are to be used, these should be placed both mesially and distally no more than one week prior to crown placement. 2. Remove soft caries (or no caries removal). 3. Select crown of appropriate size. Dividers can be used to measure mesiodistal dimension of tooth. 4. Fill crown with glass ionomer cement and position evenly over the occlusal surface. 5. The child is asked to bite gently down onto a cotton-wool roll whilst the operator observes to ensure the crown is seating equally. Alternatively, where a child may not wish to bite down, the operator can use firm finger pressure to seat the crown. 6. Remove excess cement and reassure the child that the occlusion will equilibrate within a month. Atraumatic Restorative Treatment (ART) In this technique, caries is removed using hand instruments with no local anaesthesia and restored with glass ionomer. Designed for use in developing countries where facilities and staff are limited, it can be useful as part of acclimatization with young children or in dentalphobic patients. Chemomechanical caries removal Chemomechanical removal has become more reliable with com­ mercial kits now available (e.g. Carisolv™). Two gels are mixed to create the active agents (sodium hypochlorite and amino acids) which separate carious from sound dentine – the addition of dyes improves visibility. The mixed gel is placed on carious dentine for 20 seconds, then scraped gently with specifically designed hand http://dentalebooks.com Paediatric dentistry • 441 instruments. The gel becomes cloudy and is removed by washing; the process is repeated until the gel remains clear. The tooth is then restored as normal. Pulp therapy This section describes pulp therapy in primary teeth and in immature permanent teeth. Pulp therapy in mature permanent teeth is described in Chapter 19. Pulp therapy in primary teeth When a child presents with pulp pathology the dentist must decide whether to extract the tooth or carry out pulp therapy. Advantages of pulp therapy • • • • • maintains an intact arch tooth acts as a space maintainer introduces child to operative dentistry avoids physical and psychological trauma of extraction avoids need for extraction in cases where surgery is contraindicated, e.g. patients with haemophilia. Pulp therapy is contraindicated when • • • • • • tooth is pathologically mobile caries involves root canals or bifurcation mouth general condition is poor – numerous carious teeth cooperation is poor haematogenous spread of infection could be a problem (e.g. congenital or acquired heart condition) tooth is likely to be shed within 2 years. Pulpal pain diagnosis and choice of therapy The diagnosis of pulpal pain is discussed in detail in Chapters 3 and 19. In children, obtaining a pain history is complicated by the fact that patients may be unable to be accurate and information must be obtained from the parent/carer and from clinical examination. Marginal ridge cavitation greater than 4 mm is associated with pulp pathology in over 90% of cases. Positive pain history suggests pulp pathology. Nature of pain reflects type of pulp pathology and thus influences choice of therapy. Transient pain. Suggests vital pulp and pathology limited to coronal pulp. Can be due to: • • exposed dentine or leaking restoration – treated by covering exposed dentine/replacing restoration limited carious exposure – treated by single-visit pulpotomy. http://dentalebooks.com 442 • C L I N I C A L D E N T I S T RY Spontaneous pain. Occurs in the absence of direct stimulus, frequently at night. Indicates: inflammation throughout pulp chamber and extending into canals; non-vital pulp and periapical infection. Single-visit pulpotomy is contraindicated. Treated by either multivisit pulpotomy or pulpectomy. Pulp therapy techniques Indirect pulp capping. There is an increasing awareness that by not removing all cariously affected dentine, the natural healing and regenerative capacity of the dentino-pulpal complex can be harnessed. When removing caries from a cavity, the operator would clear carious tissue from the margins of the cavity but firm, carious dentine can be left over the floor of the cavity to avoid pulpal exposure. This will only be effective where a complete marginal seal to the restoration can be achieved such as by the placement of a bonded restoration or pre-formed metal crown. Direct pulp capping. Poor results in primary teeth; therefore, where pulp is compromised, pulpotomy is preferred. Pulpotomy. involves removal of the entire coronal pulp. Can only be performed on vital teeth. A pre-treatment radiograph is required. Formocresol is no longer recommended because of concerns over the carcinogenicity of formaldehyde. Vital pulps may be hyperaemic and bleed vigorously. Following amputation of the coronal pulp the bleeding should arrest; if this occurs, the tissue is presumed to have the capacity to recover. Under these conditions the medicament of choice at present remains ferric sulphate. Suitable alternatives are calcium hydroxide and Mineral Trioxide Aggregate (MTA). Dental dam is recommended to avoid salivary contamination. Technique 1. 2. 3. 4. 5. Give LA and place dental dam, if at all possible Remove all caries then remove roof of pulp chamber. Use sharp sterile excavator to remove coronal pulp. Irrigate with saline, stop bleeding with light pressure. If bleeding stops: Apply cotton-wool pellet moistened with 15% ferric sulphate to pulp stumps for 15 seconds. This step can be repeated once if pulp is still bleeding. 6. Irrigate gently with saline and remove moisture with cotton-wool pellet. 7. Place thick mix of zinc–oxide eugenol base in pulp chamber. 8. Restore with preformed metal crown. Pulpectomy Non-vital pulps and pulps that do not stop bleeding following amputation of coronal pulp may be suitable for pulpectomy. In this http://dentalebooks.com Paediatric dentistry • 443 technique, an attempt is made to remove radicular pulp tissue using both instruments and copious irrigation with sodium hypochlorite or chlorhexidine, following which pure zinc oxide paste is placed in the root canals. Whilst pulpectomy and root canal filling is the obvious choice for treating pulp pathology in mature permanent teeth (Chapter 19), the technique in the primary dentition is complicated by: the long thin irregular root canals in primary molars; multiple ‘blind channels’ in molar pulps making complete pulp removal impossible; physiological resorption; exfoliation; difficulty in gaining adequate access to posterior teeth in young children; risk of damage to crown of developing successor. In some cases tooth extraction may be preferred. Difficulties with analgesia and cooperation Where a child presents with irreversible pulpitis and adequate local anaesthesia cannot be achieved to allow extraction or pulpectomy to be performed, the devitalizing medicament of choice is a steroid/ antibiotic preparation (e.g. Ledermix™), which can be placed over the exposure site and temporized. Extraction or pulpectomy must then be completed at a second visit as described above. Due to the potential carcinogenic properties of paraformaldehydecontaining devitalizing pastes, their use can no longer be justified. Review and follow-up All teeth that have undergone pulp therapy should be reviewed at regular intervals, both clinically and radiographically. Pulp therapy in immature permanent teeth (open apices) Pulp therapy may be required as a result of carious exposure or trauma. Caries Carious exposure within a few years of eruption indicates high caries risk and careful consideration should be given to the overall treatment plan for the patient. In first permanent molars, pulp exposure is most likely due to caries. If the dentition is crowded, extraction may be the preferred option – an orthodontic opinion should be sought. Alternatively, it may be desirable to maintain temporarily whilst other teeth develop and erupt. Trauma In anterior teeth the exposure is usually due to trauma which most commonly arises following injury to the upper incisors at age 8–9 http://dentalebooks.com 444 • C L I N I C A L D E N T I S T RY years with subsequent pulpal involvement. As the root canal morphology of an immature tooth differs from the mature and fully formed tooth (incomplete apical development and wide canals), alternative endodontic techniques are required. The pulp therapy technique to be employed in immature permanent teeth is dependent on whether the tooth is vital or non-vital. Vital permanent teeth with open apices Indirect pulp cap. Used in deep asymptomatic carious lesions. The aim is to remove bulk of carious dentine without pulp exposure and induce formation of secondary dentine. The technique is described on page 442. Direct pulp cap. Used in small asymptomatic exposures, which are either iatrogenic, caries-related or following dental trauma (in small exposures of less than 24 hours duration). Coronal pulpotomy. Used in traumatic injuries where the pulp has been exposed for more than 24 hours and/or the size of pulp exposed is large. Partial coronal (Cvek) pulpotomy. Removal of superficial exposed pulp (2–3 mm) is carried out and calcium hydroxide placed over the remaining healthy coronal pulp. The aim is to induce a calcific bridge, but maintain a vital coronal and radicular pulp to allow normal crown and root maturation (Figure 16.1A). Technique 1. Give LA and place dental dam if at all possible. 2. Clean the tooth with sodium hypochlorite (endodontic solution). 3. Perform pulpotomy to a depth of 2–3mm with a sterile round diamond bur with water or saline spray. 4. Press a saline moistened cotton pellet against pulp wound until bleeding stops. 5. Apply calcium hydroxide over exposed pulp. 6. Cover pulpotomy material with glass ionomer cement and seal dentine with bonded composite and fully restore anatomical form with bonded composite if time and patient cooperation permits. Full coronal pulpotomy. Having undertaken a partial pulpotomy, where the remaining pulp is hyperaemic or does not bleed at all (unhealthy), the remaining coronal pulp is then removed and calcium hydroxide placed over the healthy radicular pulp stump. The aim is to induce a calcific bridge but maintain a vital radicular pulp and induce completion of root formation (Figure 16.1A.). If the radicular pulp is also unhealthy, then progress to pulpectomy, as described below. http://dentalebooks.com Paediatric dentistry Open apex Instrument to 1 mm from apex Wide palatal access (i) Remove necrotic pulp A Pack MTA to form 4 mm deep plug at apex Temporary access dressing (iii) Dress with Ca(OH)2 • Long flexible narrow guage syringe tip Inject with non setting Ca(OH)2 to fill canal (ii) Dress with Ca(OH)2 MTA plug Back fill canal with cutta percua Definitive access destoration (iv) Obturation and restoration Vital pulp open apex Bacterial contamination (i) Pulp exposure Vital radicular pulp Vital pulp Calcium Calcium hydroxide hydroxide OR Glass ionomer Glass ionomer cement cement Composite Composite resin resin (iii) Full coronal (ii) Partial (even) pulpotomy removing pulpotomy Removing all coronal pulp 2-3 mm pulp B Figure 16.1 (A) Pulp therapy for vital immature permanent teeth. (B) Pulp therapy for non-vital immature permanent teeth. http://dentalebooks.com 445 446 • C L I N I C A L D E N T I S T RY Technique 1. Give LA and place dental dam if at all possible. 2. Clean the tooth with sodium hypochlorite (endodontic solution). 3. Widen access to the pulp chamber sufficiently to allow removal of all coronal pulp tissue as far as the cervical constriction at the level of the crown/root junction. This is best performed initially with a diamond bur with water or saline spray and then coronal pulp tissue removal completed with a sterile excavator. 4. Press a saline moistened cotton pellet against radicular pulp stump until bleeding stops. 5. Apply calcium hydroxide over exposed pulp. 6. Cover pulpotomy material with glasss ionomer cement and restore access cavity and crown anatomy with bonded composite. Non-vital permanent teeth with open apices Pulpectomy. Where marked pulpitis is present, a tooth is non-vital, or pulpotomy has failed and it has been decided to maintain a young permanent tooth, pulpectomy, root end closure and obturation of the full root canal system is the treatment of choice (Figure 16.1b). Technique 1. Under dental dam, gain access to root canal. 2. Local anaesthetic may be necessary as vital granulation tissue often present at apex. 3. Place file in canal and radiograph to determine working length (remember root formation incomplete – therefore correspondingly shorter). 4. Remove debris from canal with files +/− ultrasonics, and irrigate copiously with sodium hypochlorite (providing robust individual tooth isolation has been achieved with dental dam, otherwise aqueous chlorhexidine may be used). 5. Dry canal with paper points and dress with calcium hydroxide paste. 6. Review within 1 month and remove calcium hydroxide paste and place an MTA apical stop. 7. At a following visit when the MTA has set, the canal is filled with guttapercha (GP) which, given the typically wide canal of an immature tooth, is likely to require the use of thermoplastic GP. Traumatic injuries Trauma to children’s teeth is common, and one of the true emergencies in dental practice. In these circumstances, the child and parents/ carers are likely to be anxious or distressed. Prompt and appropriate action by the dental professional not only provides reassurance but can also influence markedly the results obtained. http://dentalebooks.com Paediatric dentistry • 447 Prevalence The last Child Dental Health Survey (2013) reported the prevalence of trauma to the permanent incisor teeth to be 12% of all 12 year old children. Aetiology Related to age and gender (mainly male children). Common causes include: toddlers – trips and falls; older children – bicycle accidents; teenagers – contact sports, fights, alcohol. Remember the possibility of Non-Accidental Injury (NAI). Predisposing oral factors Increased overjet, incompetent lips. Classification of trauma Classification 1. Crown/Root fractures a. Enamel b. Enamel and dentine c. Enamel, dentine and pulp d. Enamel, dentine, pulp and root e. Root fracture (apical/middle/third) 2. Periodontal injuries a. Concussion Tooth traumatized but not loosened b. Subluxation Tooth is loosened in the socket but not displaced c. Extrusion Tooth displaced in occlusal direction d. Intrusion Tooth displaced apically into socket e. Lateral displacement Tooth pushed laterally, buccally or palatally f. Avulsion Tooth totally displaced from socket 3. Supporting bone injuries a. Dentoalveolar b. Maxillary/Mandibular/Facial bone/Nasal bone fractures (see Chapter 14) 4. Soft tissue injuries History The basic principles of taking a history and conducting an examination outlined in Chapter 7 apply. Specifically, establish: when the injury occurred – time since injury influences the prognosis; where the injury occurred; how the injury occurred; whether loss of consciousness or not; any dizziness, amnesia; anti-tetanus vaccination status. In any patient presenting http://dentalebooks.com 448 • C L I N I C A L D E N T I S T RY with dental trauma, the possibility of more serious underlying injury (e.g. concussion) should be considered (Chapter 14). Examination Extraoral Check conscious state, pulse and respiration. Exclude a head injury and spinal/chest/abdominal damage (see Chapter 14). Refer immediately to an Accident and Emergency (A&E) unit if there is any doubt. Note and diagrammatically draw orofacial swelling, bruising, laceration, limitation of movement. Examine the bony skeleton as described in Chapter 14. Intraoral • • • • • • Carefully remove adherent blood clot and debris. Count the teeth and account for any missing teeth or fragments of teeth. If soft tissue wounds are present, the possibility of fragments embedded within the tissues must be excluded (by radiograph). If tooth fracture is present, determine if pulp involved. Check occlusion. Disruption may indicate alveolar fracture. Palpate gently to determine tooth mobility – may be due to either displacement or fracture. Gently press the teeth using finger pressure before percussing the teeth if required – reaction to pressure is indicative of damage to the periodontal ligament. Where there is a history of indirect trauma (e.g. a blow to the chin) check the posterior teeth for fractures. Special tests Sensitivity (vitality) testing. Of limited value in the immediate posttrauma period, but important in long-term follow-up. The vitality of any tooth that has been subject to trauma should be reviewed at 1 month post-trauma and then at 3–6-monthly intervals for at least 2 years. Radiographs. Radiographs are most important to establish: • • • Teeth Root fractures or displacement. May require two radiographs at divergent angles to permit visualization. Periapical views are preferred. All injured teeth should be radiographed. Film holders should be used. Lips If fragments are suspected of being embedded in the lip, place film between lips and teeth, reduce exposure. Alternatively may use extraoral film held at right angles. Bony fractures If bony fractures are suspected, extraoral films are required (Chapters 8 and 14). http://dentalebooks.com Paediatric dentistry • 449 Treatment Treatment is obviously dependent on the complexity of the injury and can be described as immediate, intermediate and long-term or permanent. Objectives of treatment Immediate. Reassurance of patient and parent/carer; relief of pain; protection of pulp; suture of soft tissue lacerations; stabilization of fractured or mobile teeth. Intermediate. Pulp therapy; semi-permanent restoration. Long-term. Crown; replacement of lost teeth; orthodontic therapy to close space; removable/fixed prosthodontics. Treatment in the primary dentition A major concern with injuries to primary anterior teeth is damage to the developing permanent successors which lie palatal to, and in close proximity with, the apex of the primary teeth. Most common injuries are loosening of teeth, intrusion or avulsion. Fractures are less common. Injuries occur most frequently in toddlers; treatment options are either extraction or observation without active treatment. Extraction is indicated where radiographs show follicular involvement or if apical pathology, occlusal interference is present. If it is decided to retain the tooth, regular review is required to ensure that the tooth remains vital, is shed normally and that the permanent tooth erupts. Damage to permanent teeth is most likely with avulsions and intrusions, particularly in children under 3 years. Treatment in the permanent dentition Treatment of tooth fractures Enamel only. Use a bur to smooth sharp edges. Review pulp vitality. Enamel and dentine fracture. Can be difficult to ensure that microexposure of pulp has not occurred. Even in absence of frank haemorrhage, assume microexposure if pulp can be visualized. In definite absence of exposure, cover dentine with hard-setting Ca(OH)2 and restore using acid-etch composite technique. Composite placement is dependent on sufficient enamel remaining for retention. Preformed acetate crowns can be used as matrix, or can be built up freehand. Review pulp vitality. Pulp necrosis is uncommon but is increased by: failure to cover exposed dentine; concomitant displacement injury. http://dentalebooks.com 450 • C L I N I C A L D E N T I S T RY Fractures involving enamel, dentine and pulp. Exposure of the pulp results in microbial contamination, and pulp therapy is required. The technique to be employed depends mainly on the degree of root formation. In addition, for teeth with closed apices where complete removal of coronal and radicular pulp is required, conventional endodontics can be undertaken. Root fractures Prognosis is greatly influenced by the position of the fracture. Fracture involving the gingival third. Where a root fracture communicates with the gingival crevice, prognosis is poor. It may be possible to extract the coronal portion and root treat apical portion, extrude it and provide a post-crown. Alternatively the coronal portion can be reduced and splinted for 4 months. Fracture not involving the gingival crevice. If coronal portion is displaced, reposition and splint for 4 weeks in the first instance. Regular review is required. Longitudinal fractures. Hopeless prognosis. Explain to patient and parent and extract tooth and provide prosthetic replacement/close space orthodontically. Treatment of displacement injuries Pulp necrosis and root resorption are common following displacement injuries; degree of displacement and complete apices increase the risk. Repositioning of displaced teeth requires the use of local anaesthesia. Concussion and subluxation. Advise soft diet and review. If any mobility, especially with a fully formed apex, the tooth should be splinted for 2 weeks. Lateral displacement. Reposition, grasping tooth between forefinger and thumb. Splint for 2 weeks. Extrusion. Reposition in socket. Splint for 2 weeks. Intrusion (Mild <7mm; severe >7mm) Incomplete root. Mild: Leave to re-erupt for 1 month. If tooth fails to re-erupt, orthodontic extrusion. Severe: Surgically reposition. Complete root. Surgical reposition if recent trauma, or orthodontic extrusion if delayed presentation, The tooth will require simultaneous root canal treatment. Avulsion. It may be possible to successfully replant teeth which have been totally displaced from their sockets. Success is heavily dependent on: the time the tooth has been out of its socket; how it has been stored; how the tooth (particularly root) has been handled. http://dentalebooks.com Paediatric dentistry • 451 Prognosis for long-term survival depends largely on the extraalveolar dry time and the best prognosis is where the tooth is dry for no longer than 5 minutes. The treatment aim for most avulsed and replanted teeth is to maintain the tooth in the arch as a natural space maintainer until the maxilla is fully grown by late teens when the full range of prosthetic options may be available. The ideal place for a tooth that has been avulsed, is for it to be immediately put back into the socket. Failing this, the patient’s own saliva spat into a cup, or milk are suitable alternatives. Replantation Immediate treatment. Examine tooth, holding by the crown, rinse gently in sterile saline, avoid touching the tooth root, anaesthetize the socket, hold tooth between forefinger and thumb and replant. Splint for 10–14 days. Prescribe antibiotics. After 10-14 days. Any requirement to remove the pulp is dependent on degree of root formation and time out of socket. Complete root. Extirpate the pulp before splint removal and dress with Ca(OH)2, then root fill with GP. Incomplete root. If immediately replanted or ideally stored (i.e. in milk or saliva) and replanted within 30 minutes the pulp may be left and reviewed weekly for the first month. If any signs or symptoms of loss of vitality such as root resorption, apical rarefaction or tooth discoloration are seen, Ca(OH)2 therapy is required. If tooth replanted after 30 minutes; the pulp should be removed before splint removal and root canal dressed with Ca(OH)2. Mineral trioxide aggregate (MTA) root end closure and thermoplastic gutta-percha (GP) obturation will then be required (Chapter 19). Splinting (Table 16.1) Functions of splint Immobilize loosened tooth. Hold repositioned tooth in alignment. Protect damaged structures when teeth in occlusion. Types of splint Resin splint. Spots of phosphoric acid etchant are placed on the labial aspect of the injured tooth/teeth and one sound tooth either side. A strip of self-cure resin or composite resin is placed over the teeth and cured. Composite and wire splint. Spots of phosphoric etchant are placed on the labial aspect of the injured tooth/teeth and one sound tooth either side. A length of wire, stainless steel (circa 0.5 mm) or nickel titanium (circa 0.014 mm) is adapted to the labial contour of the teeth to be splinted. Bonding agent and spots of composite resin are http://dentalebooks.com 452 • C L I N I C A L D E N T I S T RY TABLE 16.1 Tooth injury and splinting duration Tooth injury Splinting duration Subluxation 2 weeks Extrusion 2 weeks Lateral luxation 4 weeks Intrusion 4 weeks Avulsion 2 weeks (4 weeks if EADT>60 mins) Root fracture 4 weeks (4 months if fracture close to cervical margin) Alveolar fracture 4 weeks placed on the etched surfaces and the wire pressed onto these. The composite is adapted to wrap around the wire and then cured. Duration Splinting duration is shown in Table 16.1. Review Pathology resulting from trauma to teeth is not always evident at initial presentation and may develop weeks, months or years later. Potential sequelae include: pulp death; resorption, either internal or external; calcification and obliteration of root canal, and ankylosis. All teeth that have been subjected to trauma should be reviewed regularly both clinically and radiographically. Oral pathology in children (see Chapters 3 and 13) Hard tissue pathology The most common disease to affect dental hard tissues is, of course, dental caries. Other pathology may result in abnormalities of eruption, tooth number, form, position or structure. Abnormalities of tooth number Supplemental teeth. Duplication of teeth. Permanent upper lateral incisor is the most commonly involved. Usually extract one. Supernumerary teeth. Primary teeth 0.2–0.8%, permanent teeth 1–3%, more common in males and the maxilla. Most common in upper incisor region. May be: Conical. Usually in midline; either displaces the central incisor or prevents eruption. Also found high and inverted in the palate. Tuberculate. Often paired; most commonly on the palatal side of central incisors and prevent eruption. http://dentalebooks.com Paediatric dentistry • 453 Orthodontic assessment is recommended. Must establish position with appropriate radiographic technique. Can leave if not causing any problems. Do not remove before age 6 years. If intervention is essential, space requirements must be considered. Delayed incisors may take some time to erupt and may require surgical exposure. Hypodontia. Fewer teeth than normal. Primary teeth <1%, permanent teeth 6%. Where the primary teeth are affected, 40% of permanent teeth are affected. In addition, teeth present may be smaller than average. Orthodontic assessment is recommended when planning restorative care. Missing upper lateral incisors. Can be unilateral or bilateral. If one side missing, the other side is often small and conical. Has an effect on the eruption of the permanent canine – greater chance of it being displaced palatally. Treatment options: accept; restorative alone; space closure; space localize and restorative treatment. Missing premolars. Most commonly second premolar. Must decide on retention/extraction of the second primary molar – influenced by arch crowding and tooth condition. Remember, a retained primary molar may infra-occlude. Missing lower central incisor. If crowded, reasonable space closure may result following extraction of the primary tooth. If uncrowded, may wish to retain the primary tooth as an interim measure and then, when lost, consider adhesive bridgework. May require orthodontic alignment prior to this. Abnormalities of tooth form Dens invaginatus. Must check for this (radiographically) if the lateral incisors are small and conical. Prompt placement of fissure sealant into the palatal pit can prevent pulpal pathosis. Where such a tooth becomes non-vital, endodontic treatment can be complex with reduced prognosis. Dilaceration. Abnormal angulation between the crown and root or within the root. May be related to intrusive trauma to primary dentition. May fail to erupt. Abnormalities of tooth position Impacted first permanent molars. Impact behind second primary molar due to crowding or abnormality in tooth eruption such as orientation of the crypt. Treatment possibilities include keeping under observation but must maintain good oral hygiene. May selfcorrect if mild. Alternatively, attempt dis-impaction using a separator or extract the second primary molar; this will, however, result in space loss. http://dentalebooks.com 454 • C L I N I C A L D E N T I S T RY Abnormal position of crypts. The crypt of any tooth can be displaced or rotated. Lower second premolar is most commonly affected. Little can be done at an early age. Ectopic upper canines. Incidence 1–2%; 90% lie palatally or in line of arch. Early recognition is very important. By age 9 years should be palpable as a bulge high in the buccal sulcus. If not apparent by this age then carry out a clinical examination with appropriate radiographs. The prognosis is markedly improved if detected early. Extraction of the primary canine may help to encourage eruption in the correct position. Other options: accept and review; extract; surgically expose and align orthodontically; transplant. Transposition. In the upper arch this usually involves canine and first premolar. In the lower arch it is usually the canine and lateral incisor. Difficult to correct once established. If detected early in the lower arch attempts to align the lateral to the central incisor can be instituted before the canine erupts. Abnormalities of tooth structure Result from disturbances during the period of tooth formation. Abnormal enamel Enamel hypoplasia. Enamel is reduced in thickness or of deficient structure. Presentation ranges from pits and grooves to gross abnormalities. Enamel hypomineralization. Enamel is of normal structure but not fully mineralized. Presents as changes in colour and translucency. Local aetiology. Infection, trauma, irradiation, idiopathic. Usually affects only one or two teeth. General aetiology. Environmental results from systemic disturbance during period of tooth formation. May occur pre-, peri-, or post­ natally, e.g. rubella, syphilis, childhood infections, excess exposure to fluoride. The term molar–incisor hypomineralization (MIH) is used for such defects affecting the first permanent molars and incisors. Hereditary. e.g. amelogenesis imperfecta or ectodermal dysplasia. Affects several or all teeth. Amelogenesis imperfecta. There are two common variants: (1) Hypomineralized type Matrix formation normal, calcification is abnormal. Mainly autosomal dominant. (2) Hypoplastic type Matrix formation abnormal, but any matrix formed is normally calcified. Mainly X-linked. Abnormal dentine Dentinogenesis imperfecta. Dentine consists of a reduced number of wide irregular tubules, with areas of atubular dentine. Loss of http://dentalebooks.com Paediatric dentistry • 455 scalloping at ADJ. Teeth have opalescent bluish appearance. Teeth wear rapidly as enamel is lost. Abnormal cementum Hypercementosis. May be associated with inflammation, over-/ underloading, Paget’s disease. Hypocementosis. Associated with hypophosphatasia. Bone pathology Pathological conditions affecting bone are discussed in Chapter 13. Soft tissue pathology Gingivitis is the most common disease to affect non-mineralized tissues in children. Other common conditions affecting soft tissue include aphthous ulcers, mucoceles, eruption cysts, papillomas and infections are discussed in Chapter 13. The maxim that an abnormal lesion or suspicious area affecting the oral mucosa should be further investigated holds equally true for children. Children with special needs (see also Chapter 20) Special needs describes a wide range of conditions which result in patients requiring extra attention or special facilities in order to attain and maintain oral health. Changes in the arrangements for the care of patients with special needs mean that those who may previously have resided in special centres or institutions are more likely to be accommodated in the community (normalization). It is important that these individuals continue to receive dental care. Patients with special needs are increasingly likely to seek care from general dental practitioners. Various definitions of disability have been described. They can be usefully classified as: Learning disability. Varies in severity. Can be congenital (e.g. Down syndrome) or acquired (e.g. as a result of brain damage pre-, peri- or postnatally). Physical disability. e.g. cerebral palsy, spina bifida, muscular dystrophy. Sensory disability. e.g. visual or hearing impairment. Medically compromised. Describes patients who have an underlying medical condition which may either predispose to increased dental disease or which requires special precautions when carry­ ing out dental treatment, e.g. cardiac disorders, haemophilia, transplants. http://dentalebooks.com 456 • C L I N I C A L D E N T I S T RY An individual patient may suffer a combination of these disabilities. Usually the complexity of providing dental treatment increases with the degree of disability. Prevalence of disease While the prevalence of dental caries in children who are disabled is similar to children who are not, levels of untreated disease (decayed component of dmf/DMF; Chapter 1) are higher. Risk factors Children with special needs possess certain factors which increase the risk of dental disease. Oral hygiene. Significantly poorer in many special-needs groups, especially those with learning disabilities. Down syndrome patients are predisposed to periodontal disease. Diet. Difficulty in mastication may result in soft cariogenic foods being used. Feeding time may be prolonged, increasing exposure to sugar. Confectionery may be used as reward/pacifier by parents and carers. Medication. Long-term use of sweetened medicine. Drugs may predispose to xerostomia and hyposalivation, increasing caries risk. Anti-epileptic drugs such as phenytoin may lead to gingival swelling (Drug-Induced Gingival Overgrowth; DIGO). Muscular function. Decreased muscle tone may lead to drooling of saliva, chewing problems, retention of food, reduced self-cleansing. Increased muscle tone may lead to bruxism and toothwear. Management of children with special needs History. The need for an adequate history, as in treating any patient, is obvious. Complicated by the need for more time and patience to obtain history. Need to involve parents, carers and other health professionals concerned with care of the patient. Liaison with the patient’s physician is important. Examination and treatment. Technical aspects of patient care do not differ greatly from patients without special needs. Most merely require time and patience. However, given the many other problems facing patients with special needs, dentistry is frequently given a low priority. Restorative care. Essentially the same as for all patients. In children who are more severely disabled, sedation or general anaesthesia may be required, particularly in cases of dental neglect requiring extensive care (Chapter 20). The usual sequence of treatment under GA is: removal of plaque and calculus; restorative procedures; extraction of teeth/surgery. http://dentalebooks.com Paediatric dentistry • 457 When operating under GA: avoid treatment that cannot be completed in one visit; use resorbable sutures; in cases of carious exposure where there is any doubt as to prognosis, extraction is the best option. When the patient is rendered dentally fit, every effort should be made to capitalize on preventive care and minimize the need for future general anaesthesia. Factors hindering treatment Availability of treatment. Patients may have to travel long distances and attend multiple clinics. May have to rely on ambulance transport. Access to dental premises. Consider stairs, surgery design, facilities. Attitude of parents/carers. Parental anxiety may hinder treatment. Parents may be extremely demanding. Dental care should be incorporated into the patient’s overall care plan. Prevention Prevention of dental disease is paramount and should include: dietary advice to parents/carers; fluoride supplements; appropriate arrangements for oral hygiene. Toothbrushes can be modified to permit easier use in patients with limited dexterity. Regular appointments with hygienists for scaling may be useful. Children who are severely disabled will require treatment by dentists experienced in treating patients with special needs. However, whilst challenging, the treatment of children with special needs should be within the capability of most dental practitioners and provide a rewarding experience. Safeguarding children in dental practice Dentists should be careful to avoid accidents to children on their premises (e.g. care when opening doors) and also: • • • • be aware of their shared responsibility for child protection be able to recognize signs of child abuse and neglect know how to respond when concerned about a child take steps to prepare, or reorganize, their practice to safeguard children. What is abuse? Children need to feel loved and valued in order to have the opportunity to achieve their full potential. Sadly, some suffer harm either intentionally or inadvertently through the acts or omissions of their http://dentalebooks.com 458 • C L I N I C A L D E N T I S T RY parents, carers or others. Child abuse is typically defined in four categories: physical abuse, emotional abuse, sexual abuse and neglect. There is a spectrum of severity, with only a small number of children maltreated in the most severe and persistent manner, yet many children experiencing neglect. Children from all social, cultural and religious backgrounds may be subject to abuse and neglect. Professionals need to be aware of, and sensitive to, differing family patterns, lifestyles and child-rearing practices but ‘clear that child abuse cannot be condoned for religious or cultural reasons.’ Role of the dental team Abuse or neglect may present to the dental team in a number of different ways: • • • Through signs and symptoms which are suggestive of abuse or neglect Through observations of child behaviour or parent–child interaction Through a direct allegation (sometimes termed a ‘disclosure’) made by the child, a parent or some other person Every staff member, whether dentist, dental nurse, receptionist or practice manager, has an important role in recognizing signs of abuse and neglect. All team members should know that colleagues will take their concerns seriously, value their contribution and work together for the benefit of the child. Signs of abuse and neglect Signs of physical abuse frequently present in the head and neck region and may be obvious when carrying out a dental examination. Routinely asking yourself a series of questions when assessing any injury to a child will help alert you to signs of abuse. It is important to consider: • • • • The injury itself − its extent, site and any particular patterns. How and why it occurred and whether the findings match the story given. Does the history of the injury change over time? The broader picture – including underlying risk factors for abuse. Bruising is the most common injury to a child who has been physically abused and the head is the commonest site. It is now established that bruises cannot be accurately aged from an assessment of their colour. The following features suggest the possibility of abuse: • Bruising in babies and children who are not independently mobile; http://dentalebooks.com Paediatric dentistry • • • • • 459 Bruises not overlying bony prominences, e.g. bruises on the cheeks and ears; Multiple bruises in clusters; Multiple bruises of uniform shape; Bruises that carry an imprint of an implement. Some patterns of injury are particularly concerning and should prompt the practitioner to consider the possibility of physical abuse: • • • • Parallel lines of petechial bruising across the cheek may be a slap mark. Pairs of small round bruises may be caused by pinching. A row of small round bruises on one cheek, with a single, larger bruise on the other cheek is suggestive of a grip mark, perhaps associated with force feeding. A round, punched out lesion 0.8−1 cm in diameter may be a cigarette burn. Indicators of neglect should also be elicited: • • • • • General appearance and cleanliness of the child. Signs of poor growth or developmental delay. Behavioural patterns, such as a withdrawn, unresponsive child, indiscriminate friendliness, anxiety or aggression may be a consequence of underlying emotional or sexual abuse. The way the parents or carers interact with the child may raise direct concerns, e.g. the parent who ignores the child, constantly denigrates or humiliates them, or uses abusive or inappropriate language. Overlooked untreated dental caries or other disease, delay in seeking care for a child suffering dental pain, or failure to return to complete a treatment plan that has been explained to the guardian may be indicators of neglect. What to do when concerned about a child If you have concerns that a child may be suffering abuse or neglect it is essential to do something constructive about it. The dental team is required to: • • • • Observe; Record; Communicate; Refer for assessment. All dental practices should have identified where and how to contact both their local child protection team nurses and advisors and the local social services child protection team. Each Local Safeguarding Children Board (LSCB) in England and Wales and the Regional areas in Scotland and Northern Ireland have http://dentalebooks.com 460 • C L I N I C A L D E N T I S T RY all the necessary contact details in and out of normal work hours. Follow your local guidelines. Further information on Child Protection in relation to dentistry is available on the website of the General Dental Council (www.gdc-uk .org) and the Department of Health’s ‘Child Protection and the Dental Team’ webpage (www.cpdt.org.uk). http://dentalebooks.com Periodontology Periodontal health and disease 461 Gingivitis 461 Chronic periodontitis 464 17 Diagnosis and risk assessment for periodontal diseases 472 Management of periodontal diseases 473 Periodontal health and disease In its widest sense, the term ‘periodontal disease’ includes all pathological conditions of the periodontium but predominantly refers to inflammatory diseases that are plaque-induced, i.e. gingivitis and periodontitis. Gingivitis Gingivitis is an inflammatory lesion mediated by host–parasite interactions that remains localized to the gingival tissues and does not extend to involve the periodontal ligament, cementum or alveolar bone. It is a reversible inflammation. Like the gut, the periodontium requires a resident microflora that promotes health. However, in the absence of adequate oral hygiene, dental plaque accumulates above and below the gingival margin and the biofilm changes from a ‘health promoting biofilm’, within which there is symbiosis between commensal bacteria, and between those bacteria and a ‘proportionate’ host response, to an ‘incipient dysbiosis’ that promotes significant inflammation in the adjacent gingival connective tissues. Gingivitis is reversible if the biofilm is regularly disrupted and removed by oral hygiene practices, which results in the conversion of the incipient dysbiosis back to a symbiosis. The development of gingivitis is facilitated by both local factors that retain plaque and prevent its removal and systemic factors that lead to a dysregulation of the host response, rendering it ‘hyper’-responsive. Local factors include calculus, a crowded dentition, soft tissue factors, e.g. high fraenal attachment, ledged restorations and certain prostheses. Systemic factors that influence the host response to plaque accumulation include pregnancy, puberty, obesity, poorly controlled or undiagnosed diabetes mellitus and certain blood dyscrasias. http://dentalebooks.com 462 • C L I N I C A L D E N T I S T RY Figure 17.1 Chronic gingivitis affecting the lower incisor teeth. Chronic gingivitis is painless but may lead to bleeding of the gingiva, particularly when brushing the teeth or eating hard foods such as apples. The most common features of gingivitis (Figure 17.1) are: • • • • • Bleeding on brushing Halitosis (oral malodour) Erythema Swelling Bleeding on probing by the clinician. If unremoved for a few days, plaque calcifies, above (supragingival) and/or below (sub-gingival) the gingival margin to produce calculus (tartar). The plaque that collects on calculus is harder for patients to remove and exacerbates the inflammation. Tooth brushing will not remove calculus; a dental hygienist, therapist or dentist is needed. There are three broad outcomes of early gingivitis: 1. Resolution of the inflammation and a return to clinical health. 2. Chronic gingivitis – chronic inflammation persists, but is limited to the gingivae. 3. Chronic periodontitis – in susceptible patients due to failed resolution of the inflammation and a hyper-responsive/destructive host response. Necrotizing ulcerative gingivitis (NUG) This has also been called acute ulcerative gingivitis (AUG), acute necrotizing ulcerative gingivitis (ANUG), Vincent’s disease and trench mouth. NUG is a rare, non-contagious gingival infection, which typically affects teenagers and young adults. It especially affects those with poor oral hygiene who smoke, are stressed or have poor nutrition. Other predisposing factors include viral infections and immune defects such as HIV/AIDS. http://dentalebooks.com P eri o d o nt o l o g y • 463 Figure 17.2 Necrotizing ulcerative periodontitis. The features are the same as NUG, but in addition, attachment loss is evident. Figure 17.3 Desquamative gingivitis in a patient with systemic lupus erythematosus. Characteristic features of NUG (Figure 17.2) are: • • • • • Gingival pain Ulceration of the papillae tips Profuse gingival bleeding Halitosis Bad taste. The ulceration classically affects the interdental papillae and bleeding can be spontaneous. Management of NUG is by oral debridement under local anaesthetic, improving oral hygiene and the use of antibiotics (normally metronidazole) to control the infection, because the anaerobes that cause NUG invade the gingival connective tissues. Desquamative gingivitis Desquamative gingivitis (Figure 17.3) is not a diagnosis per se, more a clinical term that describes the gingival features of an underlying dermatological condition. It is usually seen in people with skin diseases like lichen planus, mucous membrane pemphigoid, pemphigus or lupus. Patients present with persistent gingival soreness, which is http://dentalebooks.com 464 • C L I N I C A L D E N T I S T RY 1 mm of clinical recession 4 mm probing pocket depth 627 45 23 Probe penetrates beyond 3 mm from gingival margin, demonstrating formation of the true pocket Pocket lining epithelium replaces SE and JE and rate ridges form In this diagram: Clinical recession = 1 mm Probing pocket depth = 4 mm so clinical attachent loss = 5 mm Figure 17.4 Diagram illustrating true pocket formation, recession and attachment loss. worse when eating acidic foods such as tomatoes and citrus fruits. The key is to establish the true underlying cause and manage that. Specialist referral is therefore normally indicated for appropriate blood tests, biopsy and definitive diagnosis. Chronic periodontitis Periodontitis affects almost 50% of adults worldwide to some degree, increasing in prevalence to 60% of over 65-year-olds. However, only 11.2% suffer from severe periodontitis, which as an entity is now recognized as the sixth most common disease of humans. Periodontitis may be chronic or aggressive, both forms are painless but may be associated with bleeding and halitosis. There is increasing pocket depth, recession, clinical attachment loss and tooth mobility and/or drifting (Figure 17.4). Chronic periodontitis can start in the mid-teens but is typically diagnosed in adulthood. Periodontitis is an inflammatory lesion mediated by host–parasite interactions that results in loss of connective tissue attachment to the root surface and loss of alveolar bone. It is a non-resolving and irreversible inflammation. The relationship between gingivitis and periodontitis is complex. Whilst plaque accumulation almost always leads to gingivitis, it does not invariably lead to periodontitis. Plaque accumulation is a necessary pre-requisite for the development of periodontitis, but is insufficient on its own to cause the disease. The reason for this is because periodontitis is a complex disease with multiple component causes as illustrated in Figure 17.5. The specific components that contribute to disease expression vary from patient to patient both in terms of their presence or absence, and also with respect to the magnitude of their impact. The result is a clinical condition with a widely heterogeneous http://dentalebooks.com P eri o d o nt o l o g y Diabetes Biofilm • 465 Immune dysfunction Smoking Health Gingivitis Periodontitis Drugs Hormones Nutrition Stress Figure 17.5 Schematic model demonstrating examples of component causes of periodontitis. Behavioural risk factors absent Behavioural risk factors present Environmental risk factors absent Health Complement Proportionate promoting host response biofilm = PMNs symbiosis Incipient Antibody dysbiosis Proportionate (quorum PMNs ++ host response sensing bacteria) T and B cells Bact’l DNA fMLP Periodontitis DisAntibody Frank proportionate dysbiosis host response (pathogenic PMNs +++ (hyperbiofilm) Plasma inflammatory) cells Resolving inflammation High biomass Genetic risk factors absent Epigenetic effects not evident Virulence factors Non-resolving inflammation LPS DAMPs Haem ↑ GCF Connective tissue and bone damage Cytokines Antigens Antigens Low biomass Environmental risk factors evident Gingivitis Clinical health Antigens High biomass Gingipains LPS Prostanoids Failed resolution of inflammation MMPs Oxidative stress Chronic nonresolving inflammation Genetic risk factors present Epigenetic effects evident Figure 17.6 Pathogenic model. PMNs: neutrophilic polymorphonuclear leukocytes (neutrophils); DNA: deoxyribonucleic acid; fMLP: N-formylmethionineleucyl-phenylalanine (fMet-Leu-Phe); LPS: lipopolysaccharide (endotoxin); DAMPs; damage associated molecular peptides; GCF: gingival crevicular fluid; MMP: matrix metalloproteinase. From Chapple – Adapted from Periodontology 2000 2015; 69:7–17 with permission from John Wiley and Sons Inc. clinical phenotype. Susceptibility or ‘risk’ is driven by lifestyle and genetic risk factors which alter the host inflammatory-immune response, rendering the response too aggressive and causing collateral tissue damage. It is estimated that 80% of the periodontal tissue damage is due to an inappropriate host response to pathogenic bacteria. Gingival inflammation always precedes periodontitis and therefore managing gingivitis is a primary prevention strategy for periodontitis. Why only a proportion of sites with gingivitis progress to periodontitis and why this is more likely in some individuals than in others has been the subject of much research. A contemporary model of periodontal disease pathogenesis is illustrated in Figure 17.6. The key drivers are the microbial dysbiosis and a dysfunctional (overly aggressive) and non-resolving inflammatory-immune response. http://dentalebooks.com 466 • C L I N I C A L D E N T I S T RY Figure 17.7 Gingival recession affecting lower central incisors. Clinically, periodontitis is characterized by the gingiva detaching from the tooth forming a true ‘pocket’, the periodontal ligament and alveolar bone are damaged, and the gingival tissues may recede (Figure 17.7). Breakdown of the periodontal ligament and the development of a periodontal pocket is an unpredictable event. When it occurs, the rapidity with which connective tissue attachment is destroyed varies both between individuals and at individual tooth sites within the same mouth. Periodontitis may present with a small amount of bleeding only and usually no other symptoms (although sometimes mouth odour – halitosis is present) and so many patients are totally unaware there is an issue. However, periodontitis eventually leads to tooth mobility and is a major cause of tooth loss, leading to reduced quality of life and loss of self-esteem, as well as functional, speech and aesthetic problems. Contemporary microbiology of periodontitis There is a circular relationship between the dysbiotic sub-gingival plaque that associates with periodontitis and the host response, with the biofilm triggering an inflammatory response and latter providing nutrients for the former, delivered through gingival crevicular fluid. For example, iron from haemoglobin released during gingival bleeding is vital for the survival and multiplication of the periodontal pathogen Porphyromonas gingivalis. The ‘environmental plaque hy­­ pothesis’ postulates that periodontal disease is the result of a shift from a health-promoting to a disease-supporting biofilm (dysbiosis), but that within that pathogenic biofilm, commensal bacteria may be necessary to support the growth and survival of the pathogens. Using DNA probe technology, Socransky and colleagues demonstrated specific clusters of bacteria that associated with health and with active periodontitis, and presented these as coloured complexes http://dentalebooks.com P eri o d o nt o l o g y • 467 A viscosus C rectus S sanguinis V parvula S oralis S intermedius F nuc. polymorphum S constellatus S anginosus F nuc. nucleatum S gordonii E corrodens C showae C gingivalis A actino. a Sel noxia A actino. b C sputigena Pro acnes P gingivalis, T forsythia, T denticola Figure 17.8 Socransky’s colour complexes of periodontal bacteria and their associations with health and disease. (Figure 17.8). The traditionally classical pathogens Porphyromonas gingivalis, Tannerella forsythia and Treponema Denticola formed the ‘red complex’. Subsequently, molecular methods have identified over 1200 phylotypes (bacteria that cannot be cultured cannot be called species) capable of colonizing the periodontal environment, many of which cannot be grown/cultured. The precise manner by which plaque organisms induce breakdown of the periodontal tissues is not fully understood. Virulent micro-organisms capable of initiating or propagating attachment loss, if present at a critical minimal concentration in susceptible individuals, or at susceptible periodontal sites in susceptible individuals, have the ability to de-regulate the host defence mechanisms, exposing the hosts’ tissues to toxic bacterial components. As a result host cells (e.g. epithelial cells, neutrophils, monocytes and fibroblasts) are stimulated by bacterial components such as lipopolysaccharides (LPS) to produce pro-inflammatory chemical mediators called chemo­kines and cytokines. These powerful chemical messengers stimulate inflammatory responses and catabolic processes such as bone resorption and collagen destruction via reactive oxygen species (oxygen radicals) production, enzymes know as matrix metalloproteinases (MMPs) and a cell surface receptor called RANKL (Receptor activator of nuclear factor kappa-B ligand) whose expression on osteoblasts activates osteoclasts to resorb bone. Contemporary immunology of periodontitis The tissues rely on several host defence mechanisms to protect against plaque irritants. These include: • • • Sulcular and junctional epithelial cells Neutrophilic polymorphonuclear leukocytes (neutrophils/PMNs) The complement system http://dentalebooks.com 468 • • • C L I N I C A L D E N T I S T RY The cellular and humoral immune responses Chemical mediators of inflammation. In response to plaque accumulation, several pathways are activated: 1. Sulcular and junctional epithelial cells generate and release chemical signals like interleukin-8 (IL-8 or CXCL8) into the underlying connective tissues in order to stimulate inflammation. IL-8 is a chemoattractant that helps guide neutrophils into the tissues via chemotaxis. 2. Due to the release of histamine from mast cells, and other mediators like complement activation (complement components C3a and C5a) blood vessels dilate and become leaky, allowing blood serum to enter tissues carrying innate defence proteins and cells. 3. Neutrophils leave blood capillaries and enter tissues where nonspecific cell surface receptors called ‘Toll-like receptors’ bind to bacterial virulence factors like LPS, to activate the neutrophil to phagocytose the organism. 4. The increased tissue fluid results in increased gingival crevicular fluid (GCF) permeation through the junctional epithelium. This ‘transudate’ in health becomes an ‘exudate’ in disease and is rich in neutrophils and proteases and antibody that can neutralize potential pathogenic agents by phagocytosis. 5. In time tissue macrophages called ‘dendritic cells’ present bacterial antigen to T-helper cells and start the acquired immune response involving both T-lymphocytes and B-lymphocytes. The latter form antibody-producing plasma cells and the antibodies stick to bacteria and then attract neutrophils to effect their killing. In periodontitis patients defects in neutrophil function are believed to account for significant periodontal tissue damage and in some syndromes they account for the periodontitis itself. Within the neutrophils, lysosomal granules (cytoplasmic granules) contain powerful enzymes such as elastase and collagenase, which can digest bacterial products. However, these substances may also be released into the periodontal tissues in excess, causing localized tissue damage. The same is true for the release of oxygen radicals which are also associated with alveolar bone loss. Much interest has focused on the chemical mediators of inflammation and on both bacterial and host-derived enzymes as potential markers of active periodontal destruction. So far the following have been demonstrated as defective characteristics of blood neutrophils in periodontitis patients: • Hyper-reactivity – excessive release of oxygen radicals and also elastase in response to a bacterial stimulus, both of which can damage periodontal tissues. http://dentalebooks.com P eri o d o nt o l o g y • • • 469 Excess release of cytokines and chemokines like IL-8, IL-1β and TNFα in response to a bacterial stimulus, all of which generate exaggerated inflammation. Defective chemotaxis – neutrophils show poor accuracy of movement through tissues towards the bacteria. They appear to have lost their ‘satellite navigation’ system and wander about the tissues releasing the oxygen radicals, cytokines and enzymes like elastase, which damage host tissue. As gingivitis becomes periodontitis the dominant lymphocyte is the T-cell, however as periodontitis develops and becomes active then plasma cells (antibody-producing B-cells) become the dominant lymphocytes. Whereas T-cells kill bacteria themselves quite accurately (T-cytotoxic cells), plasma cells only produce antibody, and it is the dysfunctional neutrophils that bind the antibody to then kill the bacteria. Hence again, neutrophils appear to be associated with destruction even in the more specific forms of periodontal immunity. Systemic risk factors for periodontitis There are two broad groups of systemic risk factors for periodontitis: Non-modifiable risk factors – such as genetic factors, believed to account for about 50% of the disease risk; and Modifiable risk factors – are those that patients have some control over; they are largely lifestyle and environmental factors, of which poor oral hygiene, smoking, obesity and poorly controlled diabetes are the most important. Periodontal diseases are more likely with certain genetic backgrounds, although genome wide association studies have failed to identify specific gene defects, and it is possible that epigenetic effects are more influential. Epigenetic effects are changes in gene activity and expression that arise without altering the DNA sequence; the most common are chemical modifications to cytosine residues called ‘DNA methylations’ or alterations to the histone groups of the protein backbone of nuclear DNA. These epigenetic effects can even be passed through generations of people. One area where genetic defects are known to impact upon periodontal disease is in certain rare forms of syndromic periodontitis, associated with conditions such as Papillon–Lefèvre, Ehlers–Danlos or Chédiak–Higashi syndromes. With the exception of these syndromic forms of periodontitis arising due to single gene defects, specific genes have either not yet been identified or rigorously demonstrated to have a causal relationship with commonly occurring forms of periodontitis. There is no evidence of any simple pattern of genetic transmission that would support an aetiological role for a single gene mutation in chronic periodontitis. http://dentalebooks.com 470 • C L I N I C A L D E N T I S T RY Lifestyle risk factors for periodontitis • • • Cigarette smoking is one of the most robustly investigated modifiable risk factors for periodontitis and smokers have a 3–7-fold increased risk of periodontitis. There is also a dose response with people who smoke 10 cigarettes per day having a 5% elevated risk and those who smoke 20 per day a 10% increased risk. Most of the effects of smoking appear to be upon the immune response and perhaps most importantly smokers do not heal as well as non-smokers following periodontal therapy, even if their oral hygiene is good. Smokers experience significantly less reduction in pocket depths following therapy than non-smokers, with probing depth reductions and clinical attachment gains being 50% to 75% those of non-smokers following non-surgical and surgical periodontal therapy. There is some evidence that stopping smoking benefits periodontal health but it may take over 10 years from cessation for risk levels to reach those of who have never smoked. Smoking is also a risk factor for NUG and has been recognized as such since 1946. Members of the dental team have a key role to play in educating patients on the effects of smoking on oral health and on the benefits of smoking cessation The impact of poorly controlled or undiagnosed diabetes upon periodontal health status has been recognized for decades. Chronic hyperglycaemia drives inflammation and evidence over the last 15–20 years demonstrates poorer periodontal outcomes in diabetes patients whose glycaemic control is poor. Indeed, even glycaemia in non-diabetes patients is associated with poorer periodontal status and outcomes. One feature of diabetes-associated periodontitis is multiple sites of abscess formation/suppuration. Recently, studies have shown that the dental team can identify undiagnosed diabetes in periodontitis patients who also have other established risk factors for diabetes such as a family history, are overweight/obese or who have sedentary lifestyles. Importantly, improving diabetes control also improves periodontal outcomes and so the dental team also have a significant role to play encouraging better glycaemic control in diabetes patients, as well as facilitating diagnoses of diabetes. Given the global epidemic of diabetes with the WHO estimating 439 million will have diabetes by 2030 – that is 10% of the adult population of the world, then diabetes-related periodontitis could become a more significant challenge in the future. Obesity levels across the developed world have been increasing at an alarming rate since the early 1990s. By 2013 66% of English men and 57% of women were either obese or overweight and 25% of each gender were clinically obese. In 2013 9.5% of English 4–5 year olds were obese and 19% of 10–11 year olds, with 22.5% of http://dentalebooks.com P eri o d o nt o l o g y • 471 4–5 year olds and 33.5% of 10–11 year olds being overweight. Obesity has been independently associated with increased prevalence levels and severity of periodontitis, and the mechanisms appear to relate to the adipose tissue itself causing more severe inflammation by releasing inflammatory mediators called adipokines, rather like an endocrine gland secretes hormones. Once more this highlights an increasing role for the dental team in helping patients with behaviour change and healthier lifestyles in order to improve diets and increase levels of exercise. Impact of systemic diseases on periodontitis The impact of systemic conditions like diabetes and obesity upon host defence mechanisms increases the risk of periodontitis. Several other systemic inflammatory conditions of ageing are also independently associated with periodontitis, including: • • • Rheumatoid arthritis Chronic kidney disease Alzheimer’s disease. The mechanisms and directionality of these associations remains unclear, but the common link between all these conditions and periodontitis is an increased propensity towards inflammation. Impact of periodontitis on systemic diseases At a joint workshop between the European Federation of Periodontology (EFP) and the American Academy of Periodontology in 2012, the following consensus statements were developed from four systematic reviews on the relationship between periodontitis and each of: • • • Cardiovascular disease Diabetes Adverse pregnancy outcomes. Atherogenic cardiovascular disease 1. There is consistent and strong epidemiological evidence that periodontitis imparts increased risk for future atherosclerotic cardiovascular disease. 2. The impact of periodontitis on atherogenic cardiovascular disease is biologically plausible. One likely mechanism involves translocated circulating oral bacteria directly or indirectly inducing systemic inflammation that impacts upon the pathogenesis of atherothrombogenesis. 3. While in vitro, animal and clinical studies do support the interaction and biological mechanism, intervention trials to date are not adequate to draw further conclusions. http://dentalebooks.com 472 • C L I N I C A L D E N T I S T RY Diabetes 1. Severe periodontitis adversely affects glycaemic control in diabetes and glycaemia in non-diabetes subjects. 2. In diabetes patients, there is a direct and dose-dependent relationship between periodontitis severity and diabetes complications (renal and cardiovascular diseases). 3. Emerging evidence supports an increased risk for diabetes onset in patients with severe periodontitis. 4. Evidence supports elevated systemic inflammation (acute-phase and oxidative stress biomarkers) resulting from the entry of periodontal organisms and their virulence factors into the circulation, providing biological plausibility for the effects of periodontitis on diabetes outcomes. Adverse pregnancy outcomes 1. Low birth weight, preterm birth and pre-eclampsia have been associated with maternal periodontitis exposure. However, the strength of the observed associations is modest and varies according to the population studied, the means of periodontal assessment and the periodontal disease classification employed. 2. Two mechanistic pathways have been identified, one direct – oral microorganisms and/or their components reach the foetalplacental unit; and one indirect – inflammatory mediators circulate and impact upon the foetal-placental unit. 3. Although periodontal therapy has been shown to be safe and to lead to improved periodontal outcomes in pregnant women, cause-related periodontal therapy, with or without systemic antibiotics does not reduce overall rates of preterm birth and low birth weight. Currently, no clear statements can be made concerning the impact of periodontitis upon other systemic diseases/conditions as the evidence base needs to mature. Diagnosis and risk assessment for periodontal diseases Gingivitis can be diagnosed by inspection alone, but periodontitis cannot, and requires specific diagnostic tests (periodontal probing and charting, and frequently radiographs). Early diagnosis is crucial to preventing outcomes such as tooth loss. Without proper oral care, gingivitis may progress and cause inflammation in the periodontal tissues (periodontitis), with pocket formation, tooth loosening and finally tooth loss. Indeed managing gingivitis is a primary prevention strategy for managing periodontitis. http://dentalebooks.com P eri o d o nt o l o g y • 473 Given the importance of host factors to periodontal tissue damage, risk assessment has become an important part of preventive care and patient education. Online risk assessment tools have been embedded within medical practice for over a decade and more recently such tools are available for oral health and periodontal health. Tools such as the online evidence-based Previser system (www.previser.co.uk) have been validated for periodontal risk and shown to predict periodontal disease progression and tooth loss with a high degree of accuracy. More recently this system has been shown to improve patient motivation towards behaviour change by providing personalized biofeedback. Management of periodontal diseases Treatment of gingivitis is basically founded upon improvements in oral hygiene and removal of local plaque retentive factors like calculus by scaling. Since plaque is the main cause of gingivitis, use of anti-plaque agents and increased tooth brushing and interdental brushing are important to minimize the problem. The 2014 European Workshop concluded that there was no evidence for any benefit from flossing in managing gingivitis and it is essential for patients instead to use interdental brushes daily. Moreover, re-chargeable power toothbrushes provide significant benefits over manual brushes in plaque removal, and the adjunctive use of chemical agents in mouth rinses or toothpastes offer additional benefit when added to a mechanical plaque control regime. The latter however remains the mainstay of managing gingivitis and thus preventing periodontitis. Although chronic periodontitis is initiated by a dysbiotic plaque biofilm, systemic antibiotics have no place in its treatment because the host response causes the majority of tissue damage and specific target pathogens for antibiotics remain elusive. Rather, it is improvements in oral hygiene that are essential to restore and sustain a nonpathogenic (and health promoting) biofilm. In periodontitis, because tooth brushing and mouthwashes are limited in their sub-gingival reach, scaling and root surface instrumentation are essential. Mechanical debridement may be performed with hand or power driven instruments, such as ultrasonic or sonic scaling devices. There is no evidence that mechanical instruments offer advantages over hand instruments or indeed that ultrasonic instruments (>25 KHz) are superior to sonic (<25 KHz) scalers; the choice of instrument is dependent upon practitioner experience and practitioner or patient preference. The hand instruments of choice however for sub-gingival instrumentation are area-specific Gracey curettes, since they have only one cutting edge to the instrument toe and do not traumatize the soft tissue wall of the pocket. http://dentalebooks.com 474 • C L I N I C A L D E N T I S T RY Recently there has been a move away from ‘root planing’, an aggressive procedure that removes significant amounts of cementum, towards ‘root surface debridement’, which is less aggressive and preserves healthy cementum, facilitating connective tissue and bone regeneration, even with non-surgical approaches. A move towards full-mouth one-stage therapy/disinfection, where the entire mouth was debrided within 24 hours in order to theoretically prevent reinfection of treated sites by pathogens from as yet untreated sites, has been shown to offer no benefits over a more traditional staged approach. Indeed, recently it has been shown that the size of the bacteraemia induced by the one-stage treatment modality causes an elevation in body temperature and significant increases in systemic inflammation within the vasculature (raised C-reactive protein levels). This insult to the immune system has resulted in a move back towards staged treatment over a period of 2 weeks or so. Aggressive periodontitis is now no longer treated surgically in the first instance, and non-surgical debridement is recommended over 1 week to a maximum of 2 weeks, with administration of a 7-day course of Amoxicillin 500 mg TDS and Metronidazole 400 mg TDS for 7 days, commencing immediately after the last debridement. The antibiotics are required because the Aggregatibacter Actinomycetemcomitans that is associated with the disease colonizes non-periodontal sites and also invades host cells, thus avoiding mechanical removal. The antibiotic administration following biofilm removal is necessary, because provision prior to biofilm removal results in dilution of the drugs to sub-antimicrobial doses by the intact biofilm. Periodontal surgery to access the root surface visually and physically and thus facilitate thorough debridement is occasionally still necessary. Nowadays, regeneration of lost periodontal tissue with techniques such as guided tissue regeneration also requires a surgical approach. Reference Socransky, S.S., Haffajee, A.D., Cugini, M.A., et al., 1998. Microbial complexes in subgingival plaque. J. Clin. Periodontol. 25, 134–144. http://dentalebooks.com Removable prosthodontics Introduction 475 Treatment planning 476 Changes following extraction of teeth 481 Complete dentures 481 Partial dentures 490 Precision attachments 497 Copy dentures 497 Overdentures 498 Immediate dentures 499 18 Other prosthetic appliances 500 Repairs, relines and additions 501 Craniomandibular disorders 503 Maxillofacial prosthetics 506 The shortened dental arch 509 Prescription to dental technicians 509 Advice to patients: managing expectations 510 Introduction Restorative Dentistry Deals with the restoration of diseased, injured, or abnormal teeth to normal function. Includes all aspects of endodontics, periodontics and prosthodontics. [At the time of going to print, the GDC is seeking views on how it regulates the practice of Implant Dentistry.] Removable prosthodontics is the part of dentistry associated with replacing missing teeth and tissues (soft tissue and sometimes bony defects) with a non-permanent prosthesis that can be removed by a patient or carer. Prosthodontics Replacement of missing teeth and the associated soft and hard tissues by prostheses (crowns, bridges, dentures) which may be fixed or removable, or may be supported and retained by implants. [Prosthodontics is part of Restorative Dentistry.] Removable prosthodontics commonly involves the provision of dentures which can replace one or more individual or grouped tooth spaces (known as partial dentures), or a full arch of teeth (known as complete or full dentures). The scope of removable prosthodontics has widened over the years to include some non-permanent dental appliances (for example a Michigan type splint) that do not replace teeth and missing tissues but whose construction involves similar principles to the strict definition of removable prosthodontics. Successful removable prosthodontics often requires much interfacing with other dental specialties (particularly fixed prosthodontics, http://dentalebooks.com 476 • C L I N I C A L D E N T I S T RY implantology and periodontology; Chapters 12, 17, 19) to achieve optimum results. This chapter will also consider ‘Craniomandibular disorders’ in addition to removable prosthodontics. These disorders are multidisciplinary but are often considered under the remit of removable prosthodontics because management commonly involves provision of non-permanent appliances. Treatment planning History taking Obtaining a comprehensive history is critical to the prescription of appropriate prosthodontic treatment. Factors required in prosthodontic history The general principles underlying taking a history apply (Chapter 7). The following are of particular relevance in relation to prosthodontics. Patient complaints. Appearance, function, problems with present or previous appliances, pain, retching, speech, problems eating with prostheses, attitude to wearing a prosthesis. Denture history. Age of dentures? Are present dentures a matched set? When was first denture worn? How many sets of dentures worn? Material from which dentures constructed? How successful are previous dentures? General dental history. Presence of crowns, bridges, implants, periodontal problems, caries rate, state of current restorations, orthodontic therapy, splints. Previous treatment tried for present complaint. Medical history. In particular look out for anxiety and depression, history of stroke, muscle or movement disorders, surgery or chemoor radiotherapy to the head and neck. Social history. Determine mobility, obstacles to treatment. Examination Extraoral examination In prosthodontics, extraoral examination may reveal: Signs of craniomandibular disorders. such as joint clicking, masseteric hypertrophy, tenderness in joints or muscles of mastication. http://dentalebooks.com R e m o va b le p r o st h o d o ntics • 477 Facial contours. Loss of dental bulge, perioral wrinkles, angular cheilitis, vertical dimensions, or surgical defects and scarring. Overall aesthetics of dentures Intraoral examination Mucosa. Overall health of mucosa should be carefully checked. Features of particular relevance in prosthodontics include presence of hyposalivation, denture-related candidal infection, ulceration, hyperplasia or lip/cheek/tongue chewing which may indicate active parafunction. Dentures are required mainly by older patients – the group at greatest risk from potentially malignant disorders and cancer (Chapter 13). Periodontal health. In partially dentate patients, oral hygiene, gingival condition, periodontal status, mobility, drifting and prognosis of remaining teeth should be assessed. Caries. In partially dentate patients, teeth with active, recurrent or arrested caries should be identified and assessed. Take care to identify root caries. Restorations. The functional and aesthetic status of existing restorations should be determined together with assessment as to whether or not they should be replaced, and contour noted to determine suitability for prosthesis retention or support. Occlusion. Particular attention should be paid to skeletal class, overerupted teeth, tilted teeth (buccal–lingual as well as mesiodistal tilting) and crowding or spacing. Endodontic status. Teeth should be confirmed as apically healthy or unhealthy, vital or non-vital prior to denture therapy. Support of edentulous areas. Determine the quality of support in saddle areas. The degree of resorption of bone should be noted. In addition anatomical features such as presence or absence of tori, tubercles, bony or flabby ridges or muscle attachments are important. Mouth and peri-oral opening. Access for impressions should be determined by looking at peri-oral opening and whether or not there is limitation of mouth opening (trismus). Aesthetics. The aesthetics of restorations should be assessed together with patient expectations of aesthetics. Denture examination Present dentures (and in some cases previous dentures) should be examined both in and out of the mouth. http://dentalebooks.com 478 • C L I N I C A L D E N T I S T RY With existing dentures in situ consider • Is the freeway space appropriate? • Is the retruded contact position registered correctly? • Are the lips supported well? • Are both posterior and anterior occlusal planes in harmony? • Are the dentures retentive at rest? • Are the dentures stable in function? • Is there any pain on occlusion? • Does the patient like the appearance of the dentures? • Can the patient articulate properly with the dentures? • Is there any retching with the dentures? With existing dentures out of the mouth, consider • Is the base extension appropriate? Dentures are frequently underextended in lingual pouches, retromolar pads and distally on the hard palate. Dentures are frequently overextended to the external oblique ridge of the mandible. • Is the tooth position appropriate? Common problems include excessive lingual positioning of posterior mandibular teeth and excessive labial positioning of anterior teeth. • Has the denture been altered since insertion? e.g. additions, relines, repairs or excessive adjusting. • Is there any sign of parafunction? e.g. wear in excess of denture age, wear facets. Radiographic examination Comprehensive radiographic examination, particularly of partially dentate patients, can reveal: periodontal bone levels; caries; apical pathology; retained roots and unerupted teeth; ridge contours; bone height, width and pathology; anatomical features such as nerve canals and foramina, maxillary sinus; temporomandibular joint anatomy. Useful radiographs in prosthodontics are: periapicals, panoramics, occlusals, lateral cephalometric views and tomograms. Occasional use of other imaging techniques such as Cone Beam Computerized Tomography (CBCT) scanning is required in complex cases (Chapter 8). Similarly Magnetic Resonance Imaging (MRI) is being used more frequently in the management of craniomandibular disorders. Additional features of prosthodontic examination In some cases special tests are required. These are listed below: Study casts. Determine inter- and intra-arch relationships. Reveal overerupted or tilted teeth. Help in denture design. Can be used for individual tray construction. Outline difficult saddle areas. http://dentalebooks.com R e m o va b le p r o st h o d o ntics • 479 Surveying. Surveying of casts is useful in showing areas of undercut and determining potential paths of insertion, removal or displacement of prostheses. Useful in denture design. Full occlusal assessment. Determination of lateral jaw movements, etc. may be required using facebow mounting of a maxillary cast and the use of a semiadjustable articulator. Particularly useful in tooth wear and craniomandibular disorders. Diagnostic wax-up. May aid evaluation of alternatives. Can aid patient evaluation of options. Digital photography. Can help in assessment of aesthetic needs, planning and communication with technician. CBCT and three-dimensional printing. In complex cases these techniques can be useful in planning, provision of guides and provision of prostheses particularly for implant related prosthodontics (Chapter 12). Diagnosis and management A good history and thorough examination are crucial in making a sound diagnosis and effecting appropriate management of prosthodontic patients. Diagnosis in edentulous patients Patients typically fall into one of the following categories: Good denture wearers whose dentures require replacement because they are worn, lost, broken, aesthetically poor or loose. These patients usually have simple histories and present few prosthodontic problems. Good denture wearers with poor dentures. These patients have a good history but their present dentures often have a major fault, e.g. grossly excessive vertical dimension. Correction of the fault can often lead to success. Poor denture wearers who, if provided with very well designed and constructed dentures, may tolerate their dentures. These patients often have a history of many replacement dentures from different dentists, never being totally satisfied with dentures. Poor denture wearers who do not tolerate dentures despite very well designed and constructed dentures. These patients have complex histories and conventional prosthodontics can offer them little. Particularly in this group, look out for gross anatomical or support problems, unrealistic expectations, gross retching or a psychological problem. These patients require specialist care. http://dentalebooks.com 480 • C L I N I C A L D E N T I S T RY Diagnosis in partially dentate patients Patients who are partially dentate differ in their response to dentures. Important additional features of diagnosis in partially dentate patients include: Design changes. Changing a denture design may improve results, e.g. a cobalt-chrome denture rather than an acrylic denture; altering clasp positions. Denture alternatives. In partially dentate patients, fixed prosthodontics or implant-retained prosthodontics, or not wearing dentures at all, may in some cases solve denture problems. Management Preprosthetic management. In general, caries, periodontal disease and major endodontic problems must be controlled prior to prosthesis construction. In some cases, temporary relines of existing dentures (when the mucosa is traumatized) or provision of occlusal pivots (for very worn dentures with collapsed occlusion) may be required to ensure ultimate success of a prosthesis. Preprosthetic and ongoing preventive advice is essential, especially the reduction in sugary snacks and will sometimes involve the use of topical fluoride, high dose fluoride toothpastes and fluoride and other (e.g. chlorhexidine) mouthwashes. Remember – not treating is a sound option in prosthodontics. Just because there is a saddle does not mean there has to be a prosthesis, especially if there are no aesthetic or functional problems and the occlusion is stable or in harmony. Management options in prosthodontics Who? It must be decided who is the most appropriate person to make new dentures. Referral to a specialist for advice or treatment should be considered in difficult cases. What? Take history, examination and diagnosis into account for decisions such as conventional or copy denture; acrylic or cobalt– chrome denture. When? Sometimes delaying treatment is useful, e.g. to treat pre-existing mucosal infections; in craniomandibular disorders; whilst patient undergoes medical treatment; for patient personal commitments. Where? Patient mobility must be assessed to determine whether a patient can be treated in a surgery or on a domiciliary basis. http://dentalebooks.com R e m o va b le p r o st h o d o ntics • 481 How? Some cases are clinically and technically demanding, e.g. precision attachments. Dentists should ensure they and their technicians are familiar with protocols in individual cases. Changes following extraction of teeth Changes following extraction of teeth may be divided into three categories: facial, intraoral and psychological. Facial changes. Loss of the dental bulge; loss of lip support; ‘witch’s chin’; lips fold inwards and look thinner. Intraoral changes. Loss of mandibular height – 9–10 mm over 25 years, 4 mm after 1 year; loss of maxillary height is one-quarter of loss of mandibular height; decreased masticatory performance; decreased proprioceptive ability; resorption of alveolar buccal bone width. Psychological changes. Some patients find edentulousness difficult to accept, perhaps as a sign of ‘growing old’. Consequently some patients despise the thought of dentures and require careful management of expectations; indeed, some patients equate the effects of loss of their teeth to loss of a limb. Complete dentures Principles Aims Complete dentures should replace tissues and teeth in approximately the same quantities and positions from where the tissues and teeth have been lost. Complete dentures should fill the ‘denture space’. Denture space is the space previously occupied by teeth and supporting tissues. Features of complete dentures These comprise good retention, good support, good muscle balance, good occlusal balance and stability. Retention Retention is the resistance to displacement of a denture away from the ridge. Good retention gives psychological comfort. Retention requires intimate contact between denture and tissue. However, dentures can still http://dentalebooks.com 482 • C L I N I C A L D E N T I S T RY be retained following resorptive changes, achieved by neuromuscular control. In the mandible the mobility of the floor of the mouth makes retention more difficult than in the maxilla. Support Support is the resistance of vertical movement of a denture towards the ridge. Support is the foundation on which a denture rests. Effective support requires: the denture to cover the maximal surface area without moving or impinging on friable tissues; tissues most capable of resisting resorption to be selectively loaded during function; tissues most capable of resisting vertical displacement to be allowed to make firm contact with denture base during function; compensation to be made for different tissue resilience. Primary and secondary support areas, areas to be relieved and non-compensatory support areas are shown in the maxilla (Figure 18.1) and the mandible (Figure 18.2). These may require modification in the presence of flabby ridges, prominent genial or mental tubercles, etc. Muscle balance Muscle balance is achieved when the muscular forces of tongue, lips and cheeks do not dislodge a denture during functional movements of the mouth with the teeth out of contact. Posterior N/C 1ry * 2ry N/C 1ry 2ry * Anterior 1ry = Primary support area (hard palate) 2ry = Secondary support area (ridge crest) N/C = Non-contributing to support (denture border) Occasionally the midline suture and incisive * = papilla require relief Figure 18.1 Support – complete maxillary denture. R e m o va b le p r o st h o d o ntics • 483 Posterior 1ry 1ry R * 2ry R 1ry 1ry 2ry 2ry N/C † Anterior 1ry = Primary support area (buccal shelf and pearshaped pad) 2ry = Secondary support area (ridge crest and genial tubercles) N/C = Non-contributing to support (labial ridge incline) R = Relief area (lingual ridge incline and mylohyoid ridge) * = Requires relief in the presence of prominent genial tubercles † = May require relief in the presence of prominent mental tubercles Figure 18.2 Support – complete mandibular denture. Concave shapes of denture polished surfaces give a vertical seating force when buccinator contracts. A thinner denture flange in the premolar region results in more free movement of the modiolus (the site of muscle fibre decussation from buccinator and orbicularis oris muscles). Occlusal balance Occlusal balance is achieved when the forces of one denture on another do not dislodge either denture during functional jaw movements with the teeth in contact. This can be achieved by a balanced articulation. 484 • C L I N I C A L D E N T I S T RY Stability Stability is the ability of a denture to resist displacement by functional stresses. Stability gives physiological comfort. Design Complete dentures in general should have the following design features: Maximal extension of denture base. The complete denture should cover the whole of the available denture-bearing area. In the maxilla, extension posteriorly should lie just anterior to the line of flexure of the soft palate. In the mandible, care should be taken to extend the denture base into the retromolar pad and posterior lingual sulci regions. Peripheral seal. This is an area of contact between mobile mucosa and the denture surfaces and is determined at the master impression stage. Good peripheral seal is important for retention and stability. Postdam. A rounded smooth line at the junction of hard and soft palate aids the peripheral seal of a maxillary denture. Fraena. An impression technique should be used to obtain fraenal relief. Relief areas. Small tori, prominent mylohyoid ridges and prominent mental nerve foramina often have to be relieved. Retruded contact position. Complete dentures should be registered in the retruded contact position (the position of the mandible when the condyles are in their most retruded position in the glenoid fossa) as this is the most reproducible position. Balanced articulation. Complete dentures should aim to have balanced articulation, which is a continuous sliding contact of upper and lower cusps all around the dental arch during all closed grinding movements of the mandible. Freeway space. 2–4 mm of freeway space is a guide to restoration of the vertical dimension in complete denture patients although this varies depending on an individual’s mandibular movements in speech. Tooth position Upper anterior. Teeth should usually be set labial to the residual ridge. They should usually be 10 mm labial to the middle of the incisive papilla. About 2–3 mm of teeth should show when lips are apart and relaxed. R e m o va b le p r o st h o d o ntics • 485 Lower anterior. If there is little ridge resorption, teeth should be placed marginally in front of the ridge crest. In cases with lots of resorption, teeth should be placed over the buccal sulcus. Upper posterior. Teeth should be slightly buccal to the residual ridge and parallel to the ala–tragus line. Lower posterior. Teeth should be set directly over the ridge. Aesthetics. The dentist should establish individual needs of a patient and try to accommodate these without loss of important functional concepts. Materials. Contemporary complete dentures are usually made of acrylic. Occasionally in cases of parafunction where the acrylic is prone to fracture, a complete denture can be reinforced with wire mesh or have a cobalt-chromium baseplate. Rarely if there is allergy to acrylic, nylon or polycarbonate may be used. These design features are merely a guide. In individual cases one feature may have to be compromised for the sake of another, depending on patient complaints and needs. Clinical stages Stages in complete denture construction are: examination, diagnosis and treatment plan, primary impressions, master impressions, jaw registration, trial of teeth (and if required retrial), insertion of prosthesis, review. 1. Examination, diagnosis and treatment See Chapter 7. 2. Primary impressions Aims. To outline the denture-bearing area. To construct an individual tray. To show potential problems, e.g. prominent mylohyoid ridge. Clinical technique. An edentulous stock tray is selected and usually a warm impression compound is used to take the impression. In the mandible great care should be taken to place material into the lingual sulci. Then cool the impression and take a wash impression in irreversible hydrocolloid. A variety of different impression materials may be used. The impression is disinfected and sent to the laboratory where it is cast in plaster. An individual tray is made. Both the individual tray and the cast should be returned to the dentist. 3. Master impressions Aims. To accurately record the denture-bearing area. To selectively load tissues capable of resisting load. To relieve tissues that are friable. 486 • C L I N I C A L D E N T I S T RY Types of impressions Mucocompressive. An impression under load so that mucosa is reduced in volume equally and is evenly condensed. Mucostatic. An impression made without load application so that mucosa is neither compressed nor displaced. Types of individual impression trays. Individual trays are usually made of self-cure or light-cure acrylic. Trays are separated from the primary cast by wax spacers. Wax spacer thickness depends on impression material and technique chosen. Trays may be perforated and have localized relief areas or vents. Trays may have handles or stops. Clinical technique. Individual trays should be tried in the mouth prior to use. Gross overextension or infringements on muscle attachments should be corrected by trimming the tray. Maxilla. Warm tracing stick compound should be placed on the tray in the midline rugal area of the palate to act as a locating stop to correctly centre the tray. Tracing stick should also be applied in postdam areas and buccally to delineate the position of cheeks and lips. Mandible. The depth of the lingual flange is extremely important. This is checked by asking the patient to protrude his/her tongue gently. If the tray rises the flange is overextended. Warm tracing stick should be applied posteriorly in the retromolar area and on the lingual flange to define the lingual pouch. The master impressions should then be taken. Clinical techniques vary and are dependent on choice of material. The impression is disinfected and sent to the laboratory where it is cast in stone. A record block is made. Both the record block and the cast should be returned to the dentist. New digital impresssion techniques are being developed. Suitable materials for master impressions. Hydrocolloid; zinc oxide–eugenol; plaster (rarely); polysulphide; polyvinylsiloxane, polyether. 4. Jaw registration Aims. To register the jaw relationship in the retruded contact position. To determine the vertical dimension of occlusion. To determine lip support. To determine anterior and posterior occlusal planes. To record the midline correctly. To select teeth of appropriate shade, shape, size and form. Clinical aspects • • Wax record blocks are used to register the jaw relationships. These can be made more stable by addition of heat or light cured acrylic or shellac baseplates. R e m o va b le p r o st h o d o ntics • • • • • • • • • • • 487 In jaw registration the labial contour is first restored by modifying the maxillary wax block to a 90° angle between the philtrum and columella. The anterior occlusal plane is registered usually 2–3 mm below the relaxed level of the upper lip parallel to a line between the pupils. Posteriorly the upper block is trimmed by continuing the anterior occlusal plane level posteriorly in a line parallel to the ala–tragus line. The midline is marked on the block; this is usually in the centre of the philtrum but varies in cases of facial asymmetry. The lower block is then placed in the mouth and trimmed until the rims contact evenly. Vertical dimension is then checked by a Willis bite gauge or calipers, with dots on the nose and chin, or by assessing the closest speaking space of 1 mm. Use of more than one method will give a better guide. If incorrect, wax is either added or removed from the block. Once satisfied with the registration, check notches are marked on both sides between rims and final registration taken using a bite registration paste. In difficult cases, use of a facebow to record the relationship of the upper cast to the skull is useful so that a case may be set up on a semi-adjustable articulator and an accurate balanced articulation achieved. Teeth are selected for the dentures. This is often difficult. As a general rule, teeth should harmonize with the dominant colours of the complexion. In addition, tooth shape should harmonize with face shape. Patients often wish to be actively involved in tooth selection. The record blocks (registered) should be disinfected and sent to the technician with information about shades and moulds for setting up a trial of teeth. 5. Trial of teeth Aims. To check the vertical dimension of occlusion is correct. To check the horizontal jaw relationship has been registered correctly. To check the anterior and posterior occlusal planes are correct. To check the aesthetics are appropriate and that the patient is satisfied with aesthetics. Clinical aspects • • The trial dentures should be examined critically prior to insertion – is tooth position correct, e.g. lower posteriors over the ridge? Trial dentures are inserted and all design features carefully assessed. If incorrect, chairside adjustments or re-registration and retrial may be required. 488 • • • C L I N I C A L D E N T I S T RY The patient must be permitted to see the trial and an opportunity given to discuss and, if necessary, alter aesthetics, e.g. tooth shape, position, shade and colour. When both dentist and the patient are satisfied, the trial dentures should be disinfected and sent to the technician for flasking, packing and processing into heat-cured acrylic. 6. Insertion of prosthesis Aims. To deliver completed dentures to patient. To check there have been no processing errors. To instruct the patient on denture wear. Clinical aspects • • • • • The completed prostheses ideally should be presented on holding casts with an articulator. Thus the occlusion can be checked prior to patient’s arrival. The dentures should have been disinfected prior to insertion. The fitting surface of the denture should be closely inspected and any ‘blebs’ or gross undercuts removed. The dentures should be inserted and occlusal balance and muscle balance checked. If occlusal balance is incorrect, can be identified using articulation paper and modified by selective grinding. If a larger error is present it may be necessary to re-register and remount the dentures in the laboratory and grind them to an appropriate occlusion. If there are muscle balance problems, grinding of the denture periphery may be required. Obvious gross overextension should be corrected, speech checked and the patient allowed to comment on the appearance. Before leaving, the patient should be instructed about expectations of new dentures (p. 510–511). 7. Review Aims. To assess how the patient is coping with new dentures. To relieve discomfort. To motivate patient. Clinical aspects • • • • • • Patient complaints should be carefully noted. This will help determine how the patient is coping with new dentures. The aesthetics, speech and occlusion should be reassessed, retention and stability checked. The mucosa and support areas should be closely examined for signs of ulceration or redness and the dentures adjusted. If major faults exist, these may require further laboratory stages, for example reline or remounting. In difficult cases multiple review visits are often needed. Once review is completed an appropriate recall period should be decided to review the dentures long term and check the health of the oral mucosa. R e m o va b le p r o st h o d o ntics • 489 Other clinical aspects of complete dentures Special impression techniques Denture space technique. Uses an acrylic base with upstanding flanges; denture space is formed by moulding impression compound. Useful for delineating the polished surface of a denture and setting up teeth within the confines of the denture space. Upper displaceable ridge. Primary impression in mucostatic material then composition impression of the resulting cast. In the mouth composition is reheated and moulded over firm but not flabby areas. Final wash impression. This technique compresses soft supporting tissues without distortion so utilizes these areas for support. Lower unemployed ridge. Masticatory loads are borne by peripheral tissues and not the ridge, where the ridge offers poor-quality support. Primary impression in mucostatic material. An individual tray is made with perforations over ridge crest. Then a composition impression of primary cast is taken. Composition is removed from over the ridge crest and a wash impression taken. Occlusal pivots With old, worn dentures the perioral muscle activity may become deranged. Prior to construction of new dentures, masticatory muscle activity may need to be retrained to ease the transition to new dentures. Temporary acrylic pivots on existing dentures may be placed in the premolar region of the lower denture to effect these changes. Common denture problems Inadequate retention. Patient complains of denture looseness at all times (including at rest); denture can be removed from mouth with no resistance; denture drops down after being firmly seated in the mouth. Attempt to improve peripheral seal by self-cure acrylic. Relining may be required. Inadequate support. Pain on digital pressure on support areas; discomfort under denture as day goes on; burning sensation in denturebearing area with no redness or ulceration. Try and redistribute support to areas most suited. Relief by trimming of poor support areas. In some cases the support is so poor there is little that can be done. Muscle balance problem. Dentures loose only when patient eats or speaks; dentures feel too large; cheek biting; lower denture rises on tongue protrusion. Careful trimming of denture areas encroaching on muscles often solves the problem. 490 • C L I N I C A L D E N T I S T RY Occlusal balance problem. Patient wears dentures well except at mealtimes where there is pain or looseness; dentures move when teeth ground together. Selective grinding, laboratory remount and resetting of teeth help these problems. Appearance problems. Often fall into the following categories: tooth shade; tooth shape; too much or too little tooth shows; lips look odd; face looks asymmetrical; patient unhappy with appearance but uncertain about precise reason. Often management of appearance problems involves resetting of different teeth. In some cases they may be due to incorrect recording of vertical or horizontal components of occlusion. Occasional patients have totally unrealistic expectations of dentures. Speech problems. Often problem is lisping ‘f ’ and ‘v’ sounds or hissing ‘s’ sounds. May be due to problem with tooth position or vertical dimension of occlusion. Notoriously difficult problems to solve. Retching. This is a protective reflex. In some patients, even simple examination is difficult and impression taking almost impossible. In some patients there is a psychiatric element to retching. Treatment options include progressive adaptation to dentures by constructing baseplates first. Hypnotherapy or desensitizing therapy may help. Acrylic allergy. In rare cases where there is proven acrylic allergy, an alternative material like nylon or polycarbonate should be considered. Porcelain teeth are an alternative to acrylic teeth. Irritant reactions to free monomer in new dentures (corrected by re-curing) should be differentiated from genuine acrylic allergy. Partial dentures A partial denture is a prosthesis which replaces one or more, but less than all, of the natural teeth and is removable by the patient. Principles Aims There are many similarities in complete and partial denture prosthetics. Partial dentures should replace lost teeth and tissues and fill the denture space. Partial dentures should not damage adjacent teeth or restorations. Partial dentures should be designed with periodontal health in mind and should restore function and aesthetics. R e m o va b le p r o st h o d o ntics • 491 The problems in failure to restore lost natural teeth. If missing natural teeth are not replaced the following problems may occur: drifting and tilting of teeth; overeruption of teeth; decreased masticatory function; craniomandibular disorders; overloading of remaining teeth or mucosa; tooth wear; poor oral hygiene; speech problems; aesthetic problems. The negative effect of partial dentures. Whilst partial dentures provide many benefits, they have a number of potential drawbacks: increased plaque accumulation; caries; gingivitis and periodontitis; gingival stripping; overloading of abutment teeth. Partial dentures must be designed to reduce the risk of these negative sequelae. Careful patient selection is required and moti­ vation, improved oral hygiene and elimination of dental pa­­ thology in remaining teeth should be achieved prior to prosthesis construction. Design (Table 18.1) A systematic approach to partial denture design must be followed for each case. One such systematic approach is as follows: Stage 1: Classification of support for each saddle A saddle may be either mucosa borne, tooth borne or tooth and mucosa borne. Typical examples are. mucosa borne – bilateral free end saddle; tooth borne – small bounded saddle. Saddle describes that part of the alveolus from which teeth are missing. Stage 2: Connect saddles together Saddles should be connected to produce a rigid unit. TABLE 18.1 Kennedy classification of edentulous spaces Class I Bilateral free end saddle Class II Unilateral free end saddle Class III Unilateral bounded saddle Class IV Anterior (across the midline) 492 • C L I N I C A L D E N T I S T RY Types of connectors in the maxilla Anterior palatal bar. Used for an anterior saddle only or as indirect retention in a bilateral free end saddle. Mid palatal bar. Connects two posterior bounded saddles. Posterior palatal bar. Has its posterior border on the vibrating line. Only indicated as a rigid strut for the distal ends of free end saddles. Palatal horseshoe connector. For anterior saddles. Full-coverage palatal plate. Used when very few natural teeth present. Types of connectors in the mandible Lingual bar. Needs to be 4 mm deep, 3 mm thick, 1.5 mm away from the gingival margin and 1.5 mm above the highest level of floor of mouth. Lingual plate. Used when insufficient room for lingual bar. Lingual bar and continuous clasp. Provides more indirect retention than lingual bar alone but has many sharp edges. Buccal bar. Indications are very few but is occasionally useful with gross lingual tilting of posterior teeth. Sublingual bar. Lies very low in floor of mouth. Stage 3: Choose the path of insertion and delineate undercuts The partial denture must be easily inserted and removed from the mouth; therefore the denture requires a path of insertion. A study cast is required for this and a surveyor is used. Ideally a slight distal tilt of the cast is required to ensure a simple path of insertion for the patient. Suitable undercuts are surveyed and marked in pencil on the cast by the surveyor pencil. Stage 4: Resistance of movement away from the teeth Retainers are usually placed on abutment teeth. Retention is usually achieved by a clasp, which is a flexible arm, the tip of which lies in an undercut. If there are fewer than four quadrilaterally opposed retainers there is a tendency for rotation. Stage 5: Indirect retention If the direct retainers do not provide sufficient resistance then indirect retention must be considered. Indirect retention occurs where the direct retainers act indirectly to resist movement of a saddle that can only be directly retained at one end. Example of indirect retention – free end saddle. If the saddle lifts, it does so by rotation around a fulcrum on a line through the clasp R e m o va b le p r o st h o d o ntics • 493 X A C D B The incisal rest 'X' transfers fulcrum line A–B to A–C. As D rises on new fulcrum, clasps act indirectly to resist this movement. The further C is away from A–B the more effective the indirect retention. Figure 18.3 Indirect retention. tips on the abutment teeth. If the framework is extended on the other side of the fulcrum line (away from the free end saddle) as far as possible from the fulcrum, the clasps will indirectly resist movement as the saddle rises (Figure 18.3). Stage 6: Resistance of movement towards the teeth and tissues A partial denture requires support, usually provided by an occlusal rest. Without good occlusal support there may be tissue damage. Occlusal rests should transfer load to the teeth parallel to the long axis of the tooth. Where possible, a quadrilateral distribution of rests is required to minimize rotational axes. In a distal extension saddle, the most distal occlusal rest should be placed mesially on the abutment tooth to prevent torque on this tooth. Stage 7: Resistance to horizontal movement Some parts already added to the denture will resist horizontal movement, e.g. clasp arms, contours of palate, etc. Resistance to forward movement. Only a problem in a large anterior bounded saddle. Movement forward prevented by contours of tissue and framework around abutment teeth. Resistance to backward movement. A problem in free end saddles. Prevented by addition of spurs on the mesial side of the mesial abutment. Resistance to lateral movement. Bracing arms to clasps and the contour of the palate/lingual sulcus resist this movement. Stage 8: Simplification The denture design should be critically appraised and any excessive or unwanted aspects removed. 494 • C L I N I C A L D E N T I S T RY Clasp design There are many designs of clasps and only general principles are described. Undercuts. The deeper the undercut, the greater the retention. However, clasp deformation must not stress the clasp beyond its elastic limit. Therefore, for different undercut depths, different materials are appropriate: cast cobalt–chromium useful for 0.25 mm undercut; wrought gold useful for 0.5 mm undercut; wrought stainless steel useful for 0.75 mm undercut. Clasp flexibility. A long clasp arm produces a more flexible clasp, e.g. gingivally approaching clasp is more flexible than occlusally approaching clasp. A thick clasp is less flexible than a thin clasp. Aesthetics. Particularly in the anterior region, clasps may be very noticeable. Consideration should be given to placing tips in distal undercuts, gold plating the clasps or using tooth-coloured clasps. Bracing. A clasp consists of a retentive arm (which engages an undercut) and a reciprocal (or bracing) arm (which ensures that the retentive arm does not act like an orthodontic appliance). Minor connectors. When considering clasp position it is important to remember the clasp must be connected to the main denture framework by a minor connector. This is particularly important where there is little inter-occlusal space. Common types of clasp include. Occlusally approaching clasp; gingivally approaching clasp; I bar clasp (Figure 18.4). Rests Rests provide tooth support. Common types of rests include: Occlusal rests. Are placed mesially or distally on occlusal surfaces of molar or premolar teeth. Sometimes tooth preparation is required. Must not interfere with occlusion. Occlusally approaching clasp Gingivally approaching clasp Lateral view Figure 18.4 Partial denture clasps. I bar clasp R e m o va b le p r o st h o d o ntics • 495 Cingulum rests. Placed on the cingulae of incisor and canine teeth. May require tooth preparation. Guide planes Surveying frequently reveals unfavourable tilting of teeth. To obtain a favourable path of insertion, it is sometimes necessary to cut guide planes on the tooth to correspond with the path of insertion of the denture. In some instances tooth cutting is so extensive that a milled crown must be made for a tooth to obtain a satisfactory guide plane. Choice of material Partial dentures are usually made of cobalt–chromium and/or acrylic: Reasons for choosing acrylic. Cheap; transitional or immediate partial dentures; mucosa borne denture; previous history of longterm successful acrylic denture wear; resistance of patient to anterior clasping. Reasons for choosing cobalt–chromium. Definitive dentures; tooth, or tooth and mucosa borne denture; easier to keep clean; less palatal coverage; temperature discrimination. Flexible partial dentures are finding increasing use. These are made using acrylic with addition of various materials dependent on specific manufacturers which can include nylon, E-glass and fibres. Proponents claim better comfort and ability to engage undercuts without clasping. Bilateral free end saddle dentures Bilateral free end saddle dentures have particular problems. The ~500 µm resilience of the residual ridge and ~20 µm resilience of the teeth provide a huge support discrepancy. This may manifest itself in excess loading on the distal abutment teeth. To overcome this, several design concepts have been proposed for the design of this type of denture: • • • Flexible denture base Stress-breaker designs – result in trauma distal to the last abutment tooth. Floating denture base A mucostatically recorded denture base is related to the abutment teeth under pressure. Mucofunctional impression An impression technique is used to record the tissue surfaces in the shape that the residual ridges take under functional loads. This requires the use of an altered cast impression technique. Specific partial denture designs More complex designs may provide alternatives in difficult cases. They are, however, clinically and technically complex and may require the patient to have some degree of manual dexterity. 496 • C L I N I C A L D E N T I S T RY Two part. This type of denture is designed to engage alveolar or approximal undercuts on individual paths of insertion. The two parts are locked together to retain the prosthesis. Hinged flange. This denture engages alveolar or approximal undercuts by closing into them from the buccal side once the denture base is seated. Disjunct. A tooth borne element splints the natural teeth and retains a mucosal borne element which replaces the missing teeth. Useful in Kennedy Class I and II cases. Swinglock. This denture has a flange which locks after the denture is seated, engaging undercuts gingival to interdental contact points. Useful for retention but also as a mask for unsightly gingival recession. Has a splinting action. A high standard of oral hygiene is required for this design. Clinical stages The clinical stages in partial denture fabrication are similar to those in complete dentures, namely: planning, primary impressions, master impressions, jaw registration, trial, insertion and review. Some important differences Planning stages. The status of the remaining natural teeth should be looked at carefully prior to partial denture construction. Unsatisfactory restorations should be replaced, endodontics undertaken, caries treated and crowns constructed prior to beginning other stages of partial denture construction. Primary impressions. Casts are often mounted and surveyed and used for denture design. Occasionally diagnostic wax-up of tooth position is performed. Master impressions. At this stage tooth preparation may take place prior to the impression, e.g. guide planes, rest seat preparations. Jaw registration. Often record blocks are not required and maxillary and mandibular casts may be related by use of wax or silicone rubber. Trial. In the case of metal-based dentures, in addition to a trial of teeth, a trial of the casting must be undertaken. Insertion. Instructions to patients should include modifications to oral hygiene measures affecting natural teeth. Review. The effect of the dentures on the abutment teeth should be assessed. R e m o va b le p r o st h o d o ntics • 497 Precision attachments Precision attachments are used in removable prosthetics to provide additional retention. Uses. Overdentures; implant-retained dentures; bounded saddles; flexible denture base (stress breaker) in free end saddles; in conjunction with fixed prosthodontics. Types Extracoronal. Studs, bars, magnets. Intracoronal. Often in conjunction with fixed prosthodontics. A huge number of individual designs exist. Advantages of precision attachments. Retentive; aesthetics (de­­ crease need for anterior clasping); enable use of tilted teeth for retention and support. Disadvantages of precision attachments. Expensive; require large occluso-gingival and inter-ridge height; technically and clinically challenging; long-term maintenance is a problem as parts may wear and need to be replaced with obsolescence of parts being a big issue; fracture of acrylic in saddles as it is in a thin section to accommodate attachment; oral hygiene often more difficult. Case selection for precision attachment designs is critical. Consider only in well-motivated patients with good oral hygiene and controlled caries. Copy dentures Copy dentures (also known as replica dentures) are a method of producing replacement dentures which are similar in shape and dimension to the patient’s existing dentures. Indications. Older patients; patients with old, worn or loose dentures which were otherwise successful; where patient is extremely satisfied with an aesthetic result and wishes this reproduced; poor patient cooperation, e.g. dementia, autistic spectrum disorder. Advantages. Inexpensive; enhances neuromuscular adaptation to new dentures as they are basically of similar shape; one less clinical stage; registration of jaw relationship is often simple; gives technician much more of a guide to tooth position and moulds, etc. 498 • C L I N I C A L D E N T I S T RY Disadvantages. Large errors are difficult to correct; only used in complete denture prosthetics. Clinical stages 1. Modification of existing dentures, e.g. underextension of lingual pouches modified by tracing stick to lower denture. 2. Putty impression of fitting and polished/occlusal surfaces of modified existing dentures and relocated together as a mould. 3. In laboratory putty moulds are poured into copy dentures with either wax (sometimes with shellac baseplate) or pour-cure acrylic. 4. Replicas used for master impressions (usually in polyvinylsiloxane or zinc oxide-eugenol) and jaw registration at the same clinical visit. 5. Set up, trial of teeth and insertion as for a conventional complete denture. Overdentures An overdenture is a prosthesis that gains support from one or more abutment teeth by enclosing them beneath its fitting surface. Advantages of overdentures. Maintains alveolar bone; maintains proprioceptive feedback, which controls masticatory force and monitors mandibular position in function and discriminates size and texture of foods; decreases psychological trauma of tooth loss; decreases mobility of mobile teeth; eases the progression to edentulousness; may increase denture retention. Disadvantages of overdentures. Caries on abutment teeth; periodontal disease on abutment teeth; cost; more complex clini­ cally; more maintenance required; often abutments require root treatment. Indications for overdentures. Complete denture in one arch; cleft palates and surgical or traumatic defects; hypodontia; tooth wear; overerupted teeth; doubtful conventional partial denture abutments; extraction avoidance for medical reasons, e.g. in a case where there is high risk of Medication Related Osteo-Necrosis of the Jaws (MRONJ). Clinical aspects Motivated patients should be selected who can demonstrate good oral hygiene and whose caries rate is controlled. Abutment selection. Potential overdenture abutment teeth should in general fulfil the following criteria: sufficient coronal tooth substance to maintain integrity; capable of (or not requiring) endodontic therapy; periodontal status favourable; no gross bony undercuts (unless no flange required); sometimes ability to have positive R e m o va b le p r o st h o d o ntics • 499 retention on abutments is desirable; ideally, overdenture abutments should be spaced around the dental arch; adequate inter-ridge space; canine teeth are often very good candidates as overdenture abutments. Abutment teeth can be prepared – dome- or thimble-shaped. Attachments. Attachments to abutment teeth can be used to in­­ crease the retention of the overdenture. However these have certain disadvantages: increased cost; complex maintenance; increased bulk may weaken denture base; higher load onto abutment; more difficult to clean abutment. Types of attachments to overdentures commonly used are: studs, bars, magnets, hollow posts. These are either prefabricated or placed on top of gold post and diaphragms. Impression technique for overdentures. As the abutment tooth and mucosa are of varying compressibility a close-fitting individual tray, perforated over the abutment teeth, is often made. Sometimes when using prefabricated attachments there will be impression copings and individualized impression techniques depending on the type of attachment used. In such cases close attention should be paid to manufacturers’ instructions. Frequently, immediate overdentures are made with preparation of abutment teeth at the insertion stage. This requires immediate modification of the surface over the abutment teeth by use of self-cure acrylic with vent holes to the polished surface of the denture. Care of abutments. Following insertion of an overdenture the following procedures are desirable for maintenance: toothbrushing of abutments with a high dose fluoride-containing toothpaste; denture hygiene, including removal of prosthesis at night; self-application of topical fluoride to the abutments by the patient; dietary advice regarding reduction of sugar in diet; frequent recall visits to check status of abutment teeth. Immediate dentures An immediate denture is a prosthesis used to replace one or more teeth and inserted on the day of extraction of the tooth or teeth. General features. Immediate dentures may be used for complete or partial dentures. They should be considered as transitional or temporary and are therefore usually made of acrylic. Patients should be advised preoperatively of their shortcomings, i.e. retention problems, aesthetic problems, necessity for relines, initial pain and discomfort. 500 • C L I N I C A L D E N T I S T RY Treatment planning. When many teeth are to be extracted consideration should be given to either staging of extractions or postimmediate dentures (let sockets heal then make prosthesis). Reasons for immediate dentures. Aesthetics; psychological; im­­ proved masticatory function; stabilization of wound. Problems with immediate dentures. Lots of aftercare required, e.g.: temporary linings and relines; frequent adjustments; often do not equate to patient’s perceived expectations both functionally and aesthetically; sometimes considerable post-extraction discomfort, especially if dry sockets or difficult/multiple extractions involved. Clinical aspects Removing teeth from cast. The correct method of trimming a tooth to be extracted from a cast prior to immediate denture construction is to cut across from one gingival papilla to another following ridge contour. Socketing of teeth is not desirable as this limits clot size and decreases fibrous tissue deposited. Aesthetics. Digital photography pre-extraction gives a baseline position which can aid the selection of appropriate tooth position, shape and shade of denture teeth. Good aesthetics will enhance patient acceptance of immediate dentures. Flanges. If possible, immediate dentures should have full flanges rather than be gum fitted. This ensures peripheral seal although may involve undercut trimming at insertion. Follow-up. At the time of immediate denture insertion, some checks are not possible as the patient may be locally anaesthetized or swollen. Ideally the patient should be seen the following day for occlusal and other checks to be made. Other prosthetic appliances Appliances for obstructive sleep apnoea appliances. (mandibular advancement devices and tongue retaining devices). May be useful in reducing snoring and in keeping the airway open to reduce obstructive sleep apnoea. Tongue retaining devices are less well tolerated. Before using these appliances dentists will require further training on diagnosis and management of sleep apnoea. Bleaching splints. Thin flexible splints with spacers for use in dentist-controlled vital home bleaching. Gingival veneers. Useful to mask recession following periodontal disease. Gumshields. An essential feature of trauma protection in contact sports; individual custom-made soft vinyl splints can be made in a R e m o va b le p r o st h o d o ntics • 501 wide variety of colours; cheap and easy to make and should be actively promoted by dentists. Implant planning appliances. Appliances can be made to plan potential implant positions for both plain radiographic and CBCT examinations and can be used to guide surgery. Usually made of acrylic, gutta-percha or ball-bearing, inserts or radio-opaque materials integral to the appliance are placed at selected areas and radiographs or CBCT taken with this in the mouth for planning (Chapter 12). Mouthpieces for diving and wind instrument playing. Highly specialized appliances but essential for these occupations. Nightguard splints. To decrease the detrimental attritive effects of parafunctional activity on teeth, custom-made soft vinyl splints or hard acrylic Michigan type splints can be constructed and are in common use. Palatal lift appliances. Used with or without existing dentures to improve speech. Especially useful in motor-neuron disease and most successful when there is collaborative management with a speech therapist. Tooth borne orthodontic retainers as dentures. In hypodontia patients addition of teeth on retainers can act as a temporary prosthesis. Additionally, as such retainers are tooth borne they are useful temporarily to restore teeth when pressure on the mucosa from a traditional temporary denture is undesirable but aesthetic replacement essential, e.g. post-bone grafting. Trismus screws. A screw type gag can sometimes be used to promote mouth opening in cases of severe trismus. Repairs, relines and additions Repairs Denture fracture is fairly common. Common types of fracture. Midline fracture of complete dentures; tooth detaching from denture; piece of flange lost; clasp fracture; anterior maxillary saddle area fracture; acrylic saddle detaching from cobalt–chromium baseplate. Reasons for fracture. Impact, i.e. patient drops denture; work hardening, e.g. clasp fracture; thin sections of acrylic undergoing normal forces; parafunctional forces;odd habits, e.g. nail biting; close bite, e.g. anterior maxillary saddle; dentures with soft linings (very difficult to repair accurately); original denture processing problem, e.g. porosity in denture base, incorrect bonding of denture teeth to denture base. 502 • C L I N I C A L D E N T I S T RY Repair protocols Simple. If there is a simple fracture and the broken pieces of the prosthesis can be located easily together, send to laboratory without impression where the pieces can be located together, a cast poured, the fractured area removed and new acrylic processed, e.g. midline complete denture fracture. Lost part of prosthesis. An impression is taken with the prosthesis in the mouth. A cast is poured and the new part added, e.g. lost flange or broken clasp. Unrepairable. Some fractures, e.g. denture smashed into many pieces, are not repairable. Acrylic–cobalt–chromium. Use of 4-META or silicoating of cobalt– chromium may improve retention of an acrylic saddle to a cobalt– chromium baseplate. Temporary repairs. May be effected with cyanoacrylate glues or cold-cure acrylic. If persistent denture fracture occurs, re-evaluate the treatment plan. Often a replacement denture of a different design is required. Relines A reline of a denture involves placing new material on the fitting surface. Types of reline Temporary. This usually involves a soft material and is useful for tissue conditioning of grossly ill-fitting dentures prior to new denture construction. Other uses include following insertion of immediate dentures. Soft. Often uses molloplast or silicone-based materials. Useful as a cushion in patients with parafunctional habits or irregular ridges. Unfortunately plasticizer leaches, so soft linings may become hard and need fairly frequent replacement. Microorganisms may colonize linings so can be unhygienic and in addition there is some doubt over their clinical efficacy. Permanent. Hard acrylic reline. Useful in: gross peripheral seal problems; correction of errors which occurred at master impression stage; prolonging the life span of old dentures; immediate and postimmediate dentures. R e m o va b le p r o st h o d o ntics • 503 Clinical aspects. Some relining materials are available for use in the mouth and are self-cured. Usual method involves an impression of the fitting surface. The denture must be prepared prior to impression by removing overextended flanges and undercuts. Tracing stick reforms peripheral seal. Holes need to be drilled through areas, e.g. palate, to relieve pressure and an impression taken with impression paste or low-viscosity polyvinylsiloxane. Occlusion is checked during the impression procedure. The denture is processed in the laboratory and returned to the patient. Occlusion must be carefully checked as registration error is common after relines. Relines are most frequently used in complete denture prosthetics. Sectional relines of partial denture saddles are occasionally useful, especially following immediate partial dentures. Additions Describes the placing of an additional tooth or part of a denture to an existing prosthesis. Indications Immediate addition. Where a tooth is lost subsequent to denture construction and a tooth added on the day of extraction. Post-immediate addition. Where a tooth is lost subsequent to denture construction and at a later date a replacement tooth added. Retention. Where retention of a denture is poor, a clasp may be added to improve retention. Clinical aspects. Additions usually involve an impression of the arch with the denture in the mouth. Occasionally it is possible to perform a chairside addition using self-cure acrylic, although this is often temporary in nature. Craniomandibular disorders Craniomandibular disorders (CMD) (see also Chapter 14) are a range of musculoskeletal disorders affecting the temporomandibular joint (TMJ) complex (including the muscles of mastication), which may be transient and self-limiting, often resolving without serious long-term effects but causing much morbidity when they are present. Alternative names. CMD is known by several other names, some of which are not entirely synonymous: TMJ dysfunction syndrome; myofascial pain dysfunction syndrome. 504 • C L I N I C A L D E N T I S T RY Diagnosis If craniomandibular disorders are suspected a thorough pain history must be taken to exclude other non-CMD causes such as dental pain, pharyngeal or parotid neoplasia. Even chest pathology can occasionally cause pain referred to the TMJ region. Differential diagnosis. Jaw muscle disorders, e.g. muscle spasm; TMJ derangement; trauma; degenerative joint disease; inflammatory joint disease; chronic hypomobility, e.g. ankylosis; growth disorders. History. Pain history is most important. Features often include pain on waking, pain radiating to temporal region of head. May be some craniocervical pain. Pain is often chronic and recurrent but rarely constant. Symptoms and signs. Pain on function; limited jaw opening; audible joint click; signs of tooth wear or denture wear. Examination Joint examination. The TMJ should be assessed in static and dynamic positions. Static examination. Tenderness may be assessed by palpation. TMJ morphology can be assessed by MRI scan or tomography or arthroscopy. Dynamic examination Mobility. The range and limitations of TMJ movement should be recorded. Sounds. Palpation and auscultation may aid diagnosis. Muscle examination. The range, limitation of movement and pain on movement should be assessed in all functional mandibular positions. Muscle pain may also be assessed by direct palpation of masseter and temporalis muscles. Occlusal examination. Study casts and facebow registration of casts for mounting on a semiadjustable articulator may prove useful in occlusal assessment and as a diagnostic aid to management possibilities. Management Management goals in CMD. Decreased pain; decreased adverse loading; restored function; restored daily activities. Management options Patient education and palliative home care. This involves: patient reassurance; avoidance of heavy mastication, yawning, sighing, singing, object biting; home physiotherapeutic exercises; application R e m o va b le p r o st h o d o ntics • 505 of heat or cold or analgesic gels by patient to muscles. About 60% of patients are relieved by these simple methods alone. Behaviour modification. This attempts to change persistent habits, e.g. parafunction by methods such as progressive relaxation, hypnosis, lifestyle counselling and biofeedback. Drug therapy. This may relieve symptoms of CMD by reducing pain, inflammation, muscle hyperactivity, anxiety and depression. The following drugs may be useful: analgesics; non-steroidal antiinflammatory drugs; corticosteroids (short-term systemic or local injection); muscle relaxants; benzodiazepines (useful in acute trismus); tricyclic antidepressants. Exercise therapy. The following exercises of the TMJ may be useful: Repetitive exercises. Establish coordinated muscle function. Isotonic exercises. Increase range of TMJ motion. Isometric exercises. Increase muscle strength. Mobilization. Repeated joint manipulation is useful in TMJ articular disc displacement. Physical agents. Aim to produce analgesia, heat and cold, muscle relaxation and increased joint mobility. Electrotherapy (TENS), ultrasound, vapo-coolants, local anaesthetic injections, botulinum toxin injections and acupuncture are occasionally useful. Splint therapy. Interocclusal splints are in common use in the treatment of CMD. Splints aim to: alter occlusal relationships and redistribute occlusal forces; prevent tooth wear; decrease bruxism and parafunction; treat masticatory muscle pain and dysfunction; modify relationships and forces within the TMJ. It is well documented that painful symptoms often decrease after splint insertion. Types of splints Stabilization splints. Flat plane or muscle relaxation splints. Work by altering mandibular posture to a more relaxed position. Made in hard acrylic. Usually worn at night time. Often initial positive response in 3–4 weeks. Repositioning splints. Mandibular Orthopaedic Repositioning Appliances (MORA). Used in disc displacement to decrease joint pain, sounds and secondary muscle pain. Work by decreasing adverse load in joint and altering condyle to disc relationship. Mandible is positioned into a protrusive position. Made in hard acrylic. May cause a posterior open bite. Poor success at maintaining joint structural changes. 506 • C L I N I C A L D E N T I S T RY Provisional splints. Often used as a short-term measure. Include soft resilient splint, anterior bite plane and occlusal pivots. Occlusal therapy. Some clinicians advocate altering occlusal loads as a treatment of CMD. There is little evidence base and this is rarely required and should only be considered and undertaken by a specialist practitioner. However, provision of posterior support in the form of partial dentures is often useful. Other therapy. Other forms of therapy include acupuncture, orthodontics, orthognathic surgery and joint surgery (useful for articular disorders but of limited value in CMD). With the vast range of potential management options available, CMD can appear most confusing. In addition, many clinicians have specific treatment regimes that are often anecdotal and ‘work for them’. In general, patient education and home care is a useful start, with perhaps progression to stabilization splints. In cases that do not respond to these treatment modalities, specialist help should be sought. Maxillofacial prosthetics Maxillofacial prosthetics is a specialist field requiring further postgraduate training. Types of defects Extraoral. e.g. missing eyes, ears, nose. Intraoral. acquired (head and neck cancer, trauma, MRONJ); congenital (cleft palate). Maxillectomy Commonly, patients with head and neck cancers such as oral, pharyngeal, tonsillar or antral cancer. Defects may be hard palate, soft palate, both hard and soft palate, pharyngeal. Must be seen preoperatively to determine prosthetic rehabilitation. Initial treatment. Surgical obturator made, often a three-part Conroy obturator; may be screwed in with champy plates; sectional gutta-percha into defect with a temporary soft lining. In dentate patients Adams clasps on remaining teeth are used for retention. At surgery, impression should be taken for interim obturator. Interim treatment. For 6 months, straightforward acrylic prosthesis made from impression at surgery then relined. R e m o va b le p r o st h o d o ntics • 507 Definitive treatment. After about 6 months, final obturator design and replacement of interim obturator. Types of obturators. One-piece hollow box; two-piece hollow box; detachable silicone or molloplast obturator; hollow box and detachable silicone or molloplast part; collapsible obturator. Choice of obturator depends on size of defect, undercuts and success or failure of interim prosthesis. In dentate patients cobalt– chromium baseplates may be used with clasping for retention. With the advent of free flaps to close wounds large obturators are less common. However a common complication on free flaps is wound breakdown and small maxillary defects are not uncommon. Use of Molloplast type obturators are most useful in these cases. Do not use hydrocolloid impression materials in maxillary defects as poor tear strength may leave them stuck in nasal conchae or tissue undercuts. Use where possible special trays with wire loops to retain material on the tray effectively. The role of the dentist in head and neck cancer care The need for maxillofacial prosthodontics is commonly due to the effects of head and neck cancer. In the developed world appropriate cancer care is by a multidisciplinary team (MDT) approach. Appropriately trained dentists are an integral part of a Head and Neck cancer MDT as cancer treatment affects the dentition as it involves surgery, chemo- or radiotherapy to the head and neck (Chapters 13 and 14). Screening. All head and neck cancer patients should be dentally screened post-diagnosis and pre-surgery and/or chemoradiotherapy by an appropriately trained person. Essential dental treatment can be carried out. Emergency alterations to prostheses can take place. Preventive advice can be given regarding hyposalivation, candidosis and caries control. Emergency prostheses can be planned and constructed. Initial plans can be formulated regarding post-cancer treatment prosthodontic rehabilitation. Post cancer follow-up. All head and neck cancer patients are routinely followed up by surgeons and other members of the MDT. An appropriately trained dentist should be available at follow-up for advice and management of dental problems post surgery and/or chemo- or radiotherapy. Coordination with dental primary care services is essential in head and neck cancer patients. Prosthodontic rehabilitation. Many head and neck cancer patients will require complex and challenging prostheses to be constructed. 508 • C L I N I C A L D E N T I S T RY This involves a multidisciplinary approach: coordination between primary and secondary dental care services; further surgical intervention to allow rehabilitation is sometimes required e.g. flap debulking, bone grafting, implant placement; in some instances, use of specialist laboratories and materials. Dental management in head and neck cancer patients in both primary and secondary care is fraught with complications and management can be complicated by radiation caries, osteoradionecrosis, recurrence of cancer, anatomical tissue loss, bulky flaps, flap breakdown, hyposalivation, radiation fields compromising potential implant sites, trismus, lip contracture giving minimal access to mouth, mucositis, infection and other medical conditions. Advice should be sought from specialists in many cases. Cleft palate In the developed world, most congenital cleft palates are repaired (Chapter 14). Occasionally, small fistulae are left, leaving an oronasal communication. Many repaired cleft patients have missing teeth, Class III occlusion and often require partial prostheses. Prevention of caries and periodontal disease is extremely important in such patients as tooth loss leaves poor support for denture retention. Unrepaired congenital clefts. Mainly an older population. Same principles apply as for definitive dentures in maxillectomy patients, although defect is usually symmetrical. Mandibular defects Types. Superior marginal, inferior marginal, segmental. Mandibular rehabilitation depends on: extent of remaining mandible; degree of deviation; quality of remaining alveolar ridge; number and condition of remaining teeth. Basic prosthetic principles apply but are complicated by prominent position of surgical fixators, e.g. champy plates, titanium mesh, wire. Soft tissues are also altered (e.g. glossectomy) and there may be anaesthesia or paraesthesia so neuromuscular control of prosthesis is limited. Sometimes use of a guide-flange prosthesis postoperation is useful to limit mandibular deviation from scarring. Osseointegrated implants have a valuable role in definitive rehabilitation of mandibular defects. Craniofacial prostheses Types. Auricular, orbital, nasal, other. This is a highly specialized form of prosthetics and is usually only carried out in specialist centres. Most prostheses are made from silicones. Sunlight leads to degeneration and so they often require yearly replacement. R e m o va b le p r o st h o d o ntics • 509 Osseointegrated implants have an increasing role in retention of these prostheses. Ocular (eye) prostheses need an ocular technician to achieve good lens colouring and the role of computer assisted design and manufacture in these prostheses is increasing. Spectacles and hairlines are useful in masking border between prosthesis and skin. The shortened dental arch Describes an arch consisting of anterior teeth and premolars. Advantages. No partial dentures are worn so potential risks of partial denture wear, e.g. caries, decreased. Most people can function adequately with a shortened dental arch. Most people have no aesthetic problems with a shortened dental arch. Simplifies dentition so oral hygiene regimes often easier. Number and complexity of restorations reduced. Disadvantages. No partial denture wearing experience so often poor transition to denture wear if a denture is required later in life. Tooth wear may be increased due to lack of posterior support. Caution should be exercised in patients with craniomandibular disorders. Overloading of premolar teeth. In patients who are severely compromised periodontally, increased mobility and drifting of teeth may result. Extraction of four premolars is a common orthodontic therapy and in such patients a shortened dental arch is extremely short. Patients with a high smile line may find a shortened dental arch aesthetically poor. The shortened dental arch is becoming a more prominent concept as an increasing proportion of the population retain teeth into old age. Generally 20 is considered the minimum number of teeth for adequate function with 9–10 contacting pairs but some people may function with less. Prescription to dental technicians Communication with dental technicians is important to the success of a prosthesis. A good working relationship will benefit all – patient, dentist and technician. In some jurisdictions clinical dental technicians (CDTs) provide complete dentures to patients without prescription and other removable dental appliances on prescription from a dentist. Dentists should ensure good communication with CDTs and an awareness of the scope of practice of CDTs to facilitate appropriate patient care. 510 • C L I N I C A L D E N T I S T RY General aspects. Treat technicians and CDTs with respect; they are highly skilled individuals and essential members of the dental team. Write instructions clearly and legibly. Ensure there is a mechanism for discussing difficult cases or problems. In complex cases or cases using precision attachments ensure good communication and that the technician has access to materials and equipment needed. Digital photography is useful for denture design and shade-matching purposes. Ensure pick-up and delivery times suit the needs of dentist, patients and technician. Allow the technician sufficient time to complete a specific task. The dentist should know the capabilities of the technician. If problems occur, look at the clinical side and ensure it is not the dentist who has made an error. Ensure the technician supplies a statement of manufacture for the prosthesis to comply with medical device regulations. Always disinfect work to be sent to a laboratory. Specific instructions Casts. The technician requires to know what material a cast should be poured in, the purpose of the cast, whether it should be surveyed or not. Individual trays. The technician should be informed of tray material, design, handles, spacers, vents, etc. Record blocks. The technician should be told of baseplate design for record blocks, e.g. wire, shellac, heat-cured (clear or pink) acrylic. Trial setting of teeth. Detailed information should be given to the technician regarding shade, shape, mould, make and setting of teeth. Processing of denture. Information regarding gingival stippling, use of coloured acrylics (e.g. for pigmented gingivae) and minute staining of teeth (for improved aesthetics) must be given to the technician at this stage. Partial denture design. This is the responsibility of the dentist. It must be communicated clearly, via design sheets or on casts, to the technician. Advice to patients: managing expectations Patients require advice on what to expect from denture wear. This should certainly be reiterated on insertion of a denture. It is prudent however to give advice before and during denture construction so that the patient is fully informed and has the opportunity to discuss aspects of denture wear he or she is unsure of with the dentist. Patients should usually be informed of the following: Coping with new dentures. Wearing new dentures can be extremely difficult and will take time and perseverance. To get used to new R e m o va b le p r o st h o d o ntics • 511 dentures they should be worn as much as possible. Dentures should not be worn overnight. Patients should not expect too much too soon from dentures. Eating with new dentures. Initially food should be cut into small pieces and only food that requires little chewing eaten. Gradually the patient should diversify and be more ambitious with foods eaten. Food often goes under the denture at first. The patient should attempt to chew on both sides at the same time. Speaking with new dentures. Speech is often a little difficult for the first few days. This usually improves relatively quickly. Discomfort with new dentures. It is quite normal to experience some discomfort after dentures are fitted. If the discomfort is minor, the patient should persevere with it until he/she sees the dentist again. If discomfort is severe the new dentures should be removed and the patient should revert to a previous prosthesis (if there is one) for a few days. Two days prior to the next visit to the dentist, the patient should recommence wear of the new dentures. This will help the dentist find the source of the discomfort. In addition the patient should be able to contact the dentist to discuss problems prior to the next visit. Looseness of new dentures. Initially dentures can feel a little loose until the patient adapts to the new shape. In most patients looseness improves with time. Cleaning of dentures. Dentures may accumulate food debris, stain, plaque and calculus, so keeping them clean is important. Dentures should be cleaned regularly after each meal using a soft brush and soap. Dentures should be immersed overnight in lukewarm water containing a tablet (or powder) of an alkaline peroxide denture cleaner. Dentures should then be cleaned using a soft brush and soap, rinsed in tap water, and re-inserted. Specific advice for patients with immediate dentures. In addition to the above advice, immediate denture patients should be informed that in the weeks and months after extractions their denture may become loose and require multiple adjustments, relines or even replacement. This page intentionally left blank Operative dentistry Diagnosis of pulpal pain 513 Treatment planning 517 Occlusion 521 Principles of cavity preparation 524 Management of the deep carious lesion 531 Alternative cavity preparation techniques 533 Crowns 534 Veneers 543 19 Inlays and onlays 547 Fixed bridges 550 Fixed–movable bridges 556 Adhesive bridges 557 Tooth wear 559 Tooth whitening 562 Microabrasion 566 Endodontics 566 Surgical endodontics 574 Relationships within restorative dentistry 576 Restorative dentistry Deals with the study, diagnosis and integrated restoration of diseased, injured, or abnormal teeth, and their supporting structures, to normal function and appearance. Includes all aspects of endodontics, periodontics and prosthodontics. [At the time of going to print, the General Dental Council is seeking views on how it regulates the practice of implant dentistry.] This chapter discusses operative dentistry, fixed prosthodontics and endodontics. For Implantology see Chapter 12. Diagnosis of pulpal pain See Chapter 3 for dental pathology. Types and features of pulpal and related pain Reversible pulpitis. Pain of short duration (seconds) on response to hot, cold or sweet things. Relieved by analgesics. Poor pain localization. Irreversible pulpitis. Pain of long duration (minutes-hours), often worse with hot stimuli, may be throbbing and dull in nature, better pain localization than reversible pulpitis, not always relieved by analgesics. 514 • C L I N I C A L D E N T I S T RY Periapical periodontitis. Dull, throbbing, often constant pain; frequently kept awake, patient can usually localize pain to a particular tooth, tender to chew on tooth, poor relief by analgesics. Cracked tooth/cusp syndrome. Pain on release of biting, sharp in nature and short duration (seconds), may be cold sensitive. Not relieved by analgesics, and patient tends to avoid chewing on the affected tooth. Localized to specific site on tooth. History Pain history is essential in the diagnosis of pulpal pain. Important features are: Pain quality Sharpness. Sharp pain can indicate, e.g. exposed dentinal tubules, fractured cusp (pulpal Aδ- fibres stimulated). Dullness. May indicate pulpal hyperaemia. Throbbing. Throbbing pain, particularly if constant, may indicate an irreversible pulpitis (pulpal C-fibres stimulated). Duration Short. (i.e. a few seconds) can indicate a reversible pulpitis but may indicate pain of non-dental origin, e.g. trigeminal neuralgia (Chapter 13). Constant. Often indicates irreversible pulpitis or one of its sequelae. May relate to non-dental pain, e.g. maxillary sinusitis. Stimuli Reaction to heat. Often irreversible pulpitis reacts to heat but not cold. Reaction to cold. Often reversible pulpitis, exposed dentine or cracked cusp. These conditions also often react to heat. Temperatures of −26 to −50°C better for testing pulpal response. Reaction to pressure. May indicate periapical or periodontal abscess. Reaction to release of pressure may indicate a cracked cusp. Reaction to sweet stimuli. Frequent occurrence in reversible pulpitis or with exposed dentine. Site and radiation History should indicate the primary site of pain and where it radiates. Pain in teeth adjacent to the tooth the patient suspects is the cause of pain, or opposing arch, is common. Referred pain from non-dental causes (e.g. sinusitis, trigeminal neuralgia) should be borne in mind. O p erati v e dentistry • 515 Pain localization is particularly difficult in low-grade reversible pulpitis and in children. Timing Pain pattern day and night is important. Pulpal pain is often worse at night. A pain history gives the clinician a guide as to the source of pulpal pain. It does not produce a diagnosis on its own. Clinical examination In dealing with pulpal or periapical pain, the examination should be conducted as follows: Visual Look for: obvious cavities or non-vital teeth; cracked cusps; fractured restorations; soft tissue swelling; sinus tracts; tooth mobility (Grades I, II or III). Probing To aid visual examination. Localized increased periodontal probing depth indicates a fracture. Percussion When coupled with pain history, tenderness on percussion using the end of the dental mirror handle is an important feature of irreversible pulpitis, periapical periodontitis and periapical abscess. Percussion should be in an apical and lateral direction and several ‘control’ teeth should be percussed to check responses. Special tests Special tests are extremely useful in confirming suspicions from a pain history and examination. Sensibility testing Use cold (−26 to −50°C), heat or electric stimuli. Important to use ‘control’ teeth. May indicate normal, exaggerated or no response to stimulus. Results for multi-rooted teeth can be equivocal. Sensi­ bility testing does not give an accurate assessment of pulpal vitality. Vitality testing Laser Doppler flowmetry measures pulpal blood flow and gives an indication of pulpal vitality, but it is not commonly used. 516 • C L I N I C A L D E N T I S T RY Radiographs Periapical radiographs. Indicate peri-radicular bony change, and they also show proximity of restorations/caries to the pulp and may give an indication of previous indirect or direct pulp capping. Periodontal bone levels and furcations are seen, and sometimes root fractures. Bitewing radiographs. Also indicate proximity of restorations/ caries to the pulp. Pulp chamber morphology and obliteration/pulp stones can be assessed accurately. Multi-rooted teeth may need two or more radiographs at different angles (parallax) to show problems. Transillumination May indicate caries mesially or distally on anterior teeth. Tooth ‘slooth’/FracFinder An aid to localizing cracked cusps. Problems in diagnosing pulpal pain To the inexperienced clinician, pain history and examination may be extremely confusing and resultant diagnosis difficult. This is particularly true when: The mouth is heavily restored. Multiple crowns, endodontically treated teeth, etc., may ‘hide’ the diagnosis. Less radio-opaque restorative materials often make radiographic diagnosis of caries difficult. Multiple pathology. In a neglected mouth multiple problems may be apparent, making it difficult to localize the source of an individual’s pain at a particular time. Non-odontogenic pain. Symptoms of idiopathic facial pain or other non-odontogenic pains may masquerade as pulpal pain. Dual pathology. Where symptoms are arising from more than one tooth simultaneously. Anxious patient or one with learning disability. May be withdrawn. Can be difficult to obtain a satisfactory history. Additionally, there may be exaggerated responses to examination. In the diagnosis of pulpal pain, intervene only on the evidence of more than one symptom or sign. If unsure of the diagnosis in a particular case, more evidence should be gathered by further special tests or repeating history or examination. Irreversible dental treatment should not be embarked upon until the diagnosis is established, and this can take time. O p erati v e dentistry • 517 Treatment planning History taking The general features of history taking and treatment planning are discussed in Chapter 7. This section discusses features specific to treatment planning in operative dentistry, fixed prosthodontics and endodontics. Factors required in history Patient complaints. Pain history of critical importance (p. 514); swelling; failed or fractured restorations; aesthetic, chewing or speech problems; tooth wear. History of treatment to teeth. When were restorations placed?; How many times have they failed?; Has tooth caused symptoms before?; How long has tooth been wearing away?; Has the tooth been traumatized? General dental history. How heavily restored is the dentition?; Have dentures been worn?; Has there been orthodontic therapy?; What treatments have been tried for present complaint?; Is the patient dentally motivated? Oral hygiene habits?; Acquired or developmental tooth loss? Medical history. In fixed prosthodontics and endodontics, relevant medical problems may alter proposed treatment. Social history. When contemplating prolonged or complex treatment, the patient’s ability to attend and co-operate with long appointments is important, as is patient mobility. Financial considerations may also impact on treatment options. Sometimes specific family history of dental disease is important, e.g. aggressive periodontitis. Examination Extraoral examination In operative dentistry, fixed prosthodontics and endodontics, extraoral examination may reveal important points: presence of swelling; signs of craniomandibular disorders, e.g. joint clicking, masseteric hypertrophy, tenderness in joints or muscles of mastication; smile-line position, general aesthetics of existing teeth and anterior restorations; trismus. In severe trismus, access to undertake restorative procedures may be impossible. Intraoral examination Soft tissues. Mucosal health is important. Features of particular relevance in fixed prosthodontics include an occlusal line from 518 • C L I N I C A L D E N T I S T RY clenching, lichenoid eruptions adjacent to restorations or desquamative gingivitis. Periodontal health. Oral hygiene level, gingival condition, perio­ dontal risk status, mobility and drifting of teeth, furcation involvement, recession and sensitivity should be assessed and charted (Chapter 17). Caries. Caries should be carefully charted. Note tooth surface affected. Differentiation should be made between active, recurrent, root surface and arrested caries. Individuals with rampant uncontrolled caries should be identified. Caries risk status must be recorded. Restorations. Existing direct and indirect restorations should be carefully probed and charted to determine marginal leakage, recurrent (secondary) caries, contour, occlusal relationship with other teeth, fracture, debonding and cleansability. Tooth wear. Both localized and generalized physiological and pathological tooth wear should be noted and assessed as mild, moderate or severe. Occlusion. Particular attention should be paid to the static and functional occlusion, tilted and overerupted teeth. Teeth involved in guidance, teeth subject to fremitus and occlusal overloading should be noted. The incisor relationship classification should be recorded. Symptomatic teeth. Examination and diagnosis of pulpal pain has been discussed previously (p. 513). Endodontic status. Suspicious or key teeth should be confirmed as apically healthy or unhealthy, vital or non-vital. Evidence of previous root canal treatment and its quality should be noted. Saddles. Edentulous saddles should be noted and particular interest paid to the examination and assessment of abutment teeth. Acquired or developmental reasons for missing teeth should be explored by asking the patient. Removable prostheses. If present, these should be examined in detail both in and out of the mouth (Chapter 18). It is extremely important to chart restorations and essential treatment needed in the patient’s case record in order that a problem list and treatment plan can be formulated. Radiographic examination Comprehensive radiographic examination is an essential feature in operative dentistry, fixed prosthodontics and endodontics to determine: caries; apical pathology; endodontic success or failure; problems with posts, e.g. perforation, short post; overhanging restoration margins; failing restorations; periodontal bone support; root fractures. O p erati v e dentistry • 519 Radiographs should be taken using doses of radiation according to the ‘as low as reasonably practicable’ (ALARP) principle (see Chapter 8). Useful radiographs in fixed prosthodontics: periapicals; bitewings; occlusals; Cone-Beam CT. Useful radiographs in endodontics: periapicals; Cone-Beam CT. Additional in the dentate patient Special tests are frequently required: percussion testing of teeth; sensibility testing; radiographs; study models; OVD (Occlusal Vertical Dimension) determination; full occlusal analysis on articulated study models; diagnostic wax-up of potential prostheses or rehabilitation. Diagnosis in the dentate patient Good history taking and thorough clinical examination techniques enable diagnosis/diagnoses and allow for appropriate patient management. The possible diagnoses in dentate patients are numerous. Most patients will fall into one or more of the categories listed in Table 19.1. Great care should be taken in ‘categorizing’ patients since an individual’s dental needs may vary throughout life. Management Prioritization of treatment is the key to effective treatment planning in operative dentistry, fixed prosthodontics and endodontics. Control of pain and infection are the first priorities (Emergency Phase Care). Thereafter, a suggested general sequence of treatment is: TABLE 19.1 Potential categories of dentate patient • • • • • • • • • • • • • Dental pain Non-dental pain Caries Tooth wear Periodontal diseases Previous misdiagnosis, e.g. treated for periodontal problem when problem may be endodontic Iatrogenic problems, e.g. previous failed crowns or endodontics Routine, e.g. symptom-free patient attending for check-up Aesthetic problem, e.g. tooth discoloration Occlusal problem Functional problem, e.g. insufficient teeth to chew adequately Traumatic problem, e.g. broken teeth following acute trauma Management problem, e.g. dental phobic, learning disability 520 • C L I N I C A L D E N T I S T RY Prevention and Stabilization Phase Care Control aetiology of problem. e.g. for caries give advice on diet, oral hygiene, use of topical fluoride. Stabilization phase. Extract unrestorable teeth; restore by simple means (usually direct intracoronal restorations) all restorable teeth; simple endodontic treatment to strategic teeth. Reassess response to treatment. Assess patient’s motivation, oral hygiene, diet; reassess problem teeth; reassess treatment plan – in some poorly motivated patients, complex treatment will inevitably fail due to poor oral hygiene; in some patients no further treatment is required. Definitive Reconstructive Phase Care This includes: premolar and molar endodontics; endodontic retreatment; provision of post-retained cores; crown and bridgework; removable prosthesis construction; dental implants. In the formulation and carrying out of treatment attempt to: keep treatment as simple as possible; construct treatment plans where there is scope to reassess and change plan; know your own professional limitations; know your patient’s limitations; refer for specialist care. Management options in operative dentistry Who? The dentist must decide who is the most appropriate person to devise and carry out treatment on the dentate patient. A hygienist or therapist is invaluable for delivering some aspects of care and specialist help should be sought for difficult cases. What? Taking history, examination and diagnosis into account, decide what to do given varying possible treatment options, e.g. consider bleaching/veneer/crown/do nothing for a discoloured tooth. When? Timing of treatment is important. Clearly, pain management is carried out as soon as possible. On the other hand, complex crown and bridgework often has time and financial implications for the patient and may have to be delayed. Where? Patients with medical problems may require treatment in a hospital setting. In older patients mobility can be a problem. How? Complex crown and bridgework, molar endodontics, retreatment endodontics, etc., are difficult and demanding for both dentist and patient. The dentist should be capable of carrying out these procedures if attempting a treatment plan involving them. Referral to specialists should be sought if treatment is beyond an individual’s limitations. O p erati v e dentistry • 521 When planning treatment in operative dentistry the dentist should take into account not just the teeth but the individual patient’s total oral health and general health needs. Occlusion Occlusion is the static or dynamic relationship of cusps or masticating surfaces of maxillary and mandibular teeth when in contact. Retruded Contact Position (RCP) of the mandible when the condyles are in their most retruded (antero-superior) position in the glenoid fossa and there is occlusal contact of the teeth. Intercuspal position (ICP) The position of maximum intercuspation of the teeth. Stable occlusion An occlusion in which overeruption, tilting and drifting of teeth cannot cause new occlusal interferences. (Sometimes a degree of occlusal instability is acceptable.) Occlusal harmony The absence of occlusal interferences, which allows mandibular movement in all excursions (with the teeth together), and does not result in discomfort, strain or harm to the teeth or masticatory apparatus. How key teeth move across each other is important. In fixed prosthodontics, a functional rather than a morphological (Angles class) approach to occlusion is required. Border (Posselt’s) movements of the mandible Bennett movement Condyle on working side moves laterally. Bennett shift Condyle on non-working side moves anterior and medial. Working side describes the side towards which the mandible deviates in lateral excursive movements. Non-working side describes the side away from which the mandible deviates in lateral excursive movements. Occlusal interferences may encroach on or expand border movements. Can occur, e.g. by tooth extraction or overcontouring of a restoration. Mandibular border movements are shown in Figures 19.1 (sagittal view) and 19.2 (transverse view): Retruded Contact Position (RCP) • • • • In 10–20% of population RCP = intercuspal position (ICP). In 80–90% of population RCP ≤2 mm posterior to ICP. The movement from RCP to ICP is termed a ‘slide’. RCP must be identified accurately when restoring a tooth involved in RCP. 522 • C L I N I C A L D E N T I S T RY ICP Protrusion RCP Posterior Anterior ICP = Intercuspal position RCP= Retruded contact position Open Figure 19.1 Mandibular border movements (sagittal view). Posterior RCP ICP Right Left Protrusion Anterior ICP = Intercuspal position RCP = Retruded contact position Figure 19.2 Mandibular border movements (transverse view). Mandibular movements Mandibular movements are defined as protrusive, retrusive and lateral (left and right). Protrusive movement Usually incisor teeth guide protrusion except in anterior open bite or Class III incisor relationships. Incisor relationship determines length and angle of protrusion, e.g. Class II division 2 occlusion with deep overbite results in nearly vertical mandibular protrusion. When building anterior restorations, the clinician would usually want to reproduce incisor relationship. In other circumstances, e.g. very worn teeth, restorations change incisor relationship and therefore protrusive guidance. Retrusive movement Retrusion is the slide from ICP to RCP. Any disturbances of an even slide may require adjustment. Care must be taken when restoring a tooth involved in a ‘slide’. O p erati v e dentistry • 523 Lateral movement Ideally canine guided occlusion with no contact on non-working side. In some cases ‘group function’ (pairs of bicuspid teeth) may guide the working side. Occlusal interferences An occlusal interference results from contact between teeth in one of the excursions so that the smooth movement of the mandible is interrupted or unfavourable guidance (e.g. non-working contact) occurs. Guidance may also be derived from unsuitable teeth in occlusal interference. Interferences are difficult to detect as periodontal proprioceptors condition the mandible to move so that interference is involuntarily avoided. Examination of the occlusion Examination of the occlusion should be a routine assessment in fixed prosthodontics. However, certain aids help in full occlusal assessment (which is often reserved for complex occlusions, tooth wear cases or when contemplating occlusal rehabilitation). Aids to occlusal examination. Articulating paper; occlusal indicator wax (0.5 mm thick); plastic/foil strips (Mylar 40 µm thick; Shimstock 8 µm thick); study models; diagnostic wax-up; facebow transfer and inter-occlusal records to permit articulation of study models. Features to be noted in occlusal examination. Degree of occlusal stability; type of lateral guidance; patient complaints (especially Myofascial Pain Dysfunction Syndrome [MPDS], chronic dental pain, mobile teeth); degree of difficulty in making mandibular movements; presence of occlusal interferences; overerupted and tilted teeth; does RCP = ICP?; smoothness and slide from RCP to ICP; presence of nonworking contacts; tooth wear/faceting; tooth mobility in excursive movements. Occlusal aims in fixed prosthodontics To leave a stable occlusion with no additional occlusal interferences. Use an Arcon articulator that is semiadjustable and allows the maxillary cast to be related to an approximation of the terminal hinge axis in advanced crown and bridgework. This type of articulator is essential and has variable condylar guidance in at least a straight line and permits adjustment to incisal guidance. Terminal hinge axis describes an axis passing through the lower part of the condyles, about which the condyles rotate when they are in their uppermost, centred position in the glenoid fossae. 524 • C L I N I C A L D E N T I S T RY Principles of cavity preparation Objective of cavity preparation • • • Removal of carious tissue. Minimize pulpal and/or periodontal damage. Cavity should be prepared such that restorative material to be used can restore function and appearance of the tooth and is retained in the tooth. Basic principles of cavity preparation Caries is a dynamic disease process involving the gain/loss of mineral from the tooth (Chapter 3). The first stage of management is always a preventive approach that focuses on the use of dietary advice and topical fluoride. However, once the carious process involves dentine most clinicians consider using an interventive approach to remove the carious tissue. The fundamental guiding principle of cavity prepa­ ration is that the preparation should only be as large as the carious lesion. Radiographs should be examined carefully using good illumination and ideally magnification to assess the extent and depth of the lesion. Although cavities vary widely, the following basic steps are common to the preparation of most cavities: 1. Outline form Outline form encompasses the carious lesion, grossly unsupported enamel, and is made up of smooth angles rather than sharp edges. 2 & 3. Resistance and retention forms These are considered together as they are achieved simultaneously. Resistance form. refers to the features of the cavity design that resist occlusal forces. Retention form. refers to the features of the cavity design that resist displacement of the final restoration. Retention form may vary depending on the material that will fill the cavity, e.g. a cavity to be filled by resin composite gains additional retention via micromechanical retention from enamel and dentine bonding. Therefore such a cavity requires less retention than a cavity that will be restored by a material such as amalgam. O p erati v e dentistry • 525 4. Management of remaining caries Removal of existing caries should be undertaken with the following general principles in mind: • The cavity margin must be caries free. • Great care should be taken to remove all caries and stained dentine from the amelodentinal junction to prevent lateral spread. • Stained but hard dentine may be left in the deepest parts of the cavity. • Soft dentine should be removed. • Caries staining dyes can help selective tissue removal. 5. Enamel margin finishing In most cavities the Cavo-Surface Angle (CSA, solid-line angle between cavity wall and tooth surface) should be around 90°. Cavity margins should be closely inspected and grossly unsupported enamel removed. However, the marginal strength, and potential for adhesion of the restorative material for a particular cavity is a major factor in determining the best CSA and the amount of unsupported enamel to be removed. 6. Cavity cleansing After mechanical cavity preparation is complete, residual debris should be dislodged with a hand instrument, the cavity cleaned with water, isolated and excess moisture removed. Desiccation of vital or non-vital dentine should be avoided, especially if dentine bonding is to be employed. Classification of cavities Black’s classification is a simple and convenient way of classifying cavities based on the tooth surfaces affected. However, it must always be remembered that the shape of any cavity is primarily dictated by the extent and spread of the caries process. Recently, it has been suggested that a Class VI cavity be added to this classification. This lesion involves wear of the incisal tips of anterior teeth (Table 19.2). TABLE 19.2 Black’s classification of cavities (See Ch. 3) I Cavity originating in anatomical pit or fissure II Cavity originating on mesial or distal aspect of molar/premolar teeth III Cavity originating on mesial or distal aspect of incisors/canines not involving incisal edge IV Cavity originating on mesial or distal aspect of incisors/canines involving incisal edge V Cavity originating in cervical third of buccal/lingual/palatal aspects of teeth (excluding anatomical pits) VI Cavities involving wear of incisal edges of upper and lower anterior teeth 526 • C L I N I C A L D E N T I S T RY Class I cavity Primary occlusal caries is usually operatively managed using a preventive resin restoration or enamel biopsy approach which is then restored with composite resin and the surrounding fissures sealed. More extensive cavities and replacement restorations are often managed with an occlusal amalgam restoration or an appropriate nano-hybrid composite restoration. Preventive resin preparation/enamel biopsy • • • • • • • • • • Initial preparation made with small pear-shaped bur Only access areas of fissure system that appear carious If no caries found, cavity can be ‘aborted’ and sealed Remove any carious dentine using small rosehead burs Remove only friable enamel margins – firm enamel will be supported with composite Do not bevel occlusal cavity margins – this will result in thin layer of composite which will fracture, stain and wear Etch cavity margins, wash and dry Apply dentine bonding agent if dentine exposed Restore cavity with composite (flowable composite may help; apply composite incrementally if cavity large) Seal remaining fissure system Class I cavity – amalgam or composite resin • • • • • • Often begins as enamel biopsy until ‘occult’ caries found at ADJ (amelodentinal junction) Initial preparation made with small pear-shaped bur CSA 90–110° (amalgam more critical) Remove grossly undermined enamel – will not be supported Use lining that will seal underlying dentine such as GIC (glass-ionomer cement) – alternatively, seal cut dentine with a dentine bonding agent (immediate dentine seal) Restore with amalgam or bonded composite resin Class II cavity There are a number of different ways to approach an approximal carious lesion. These include: • • • • Occlusal via marginal ridge – most commonly Buccally/lingually – when teeth are tilted Directly – when adjacent tooth missing Occlusally leaving marginal ridge intact – tunnel preparation. Occlusal approach – composite Most commonly used – aim to produce scoop form to cavity using pear-shaped bur. O p erati v e dentistry • • • • • • • 527 Remove any remaining carious dentine using small rosehead burs Remove all friable enamel – may leave unsupported enamel Bevel approximal enamel surface Line or seal exposed dentine with dentine bonding agent Apply translucent matrix band and wedge Restore with composite in triangular-shaped increments, taking care not to join buccal and lingual cusps Occlusal approach – amalgam • • • • • • • • Form of cavity is a scoop-box – slightly narrower occlusally than gingivally CSA 90–110° Remove all undermined enamel – will not be supported Place small vertical retention grooves using small rosehead bur in buccal and lingual walls of approximal box just inside ADJ Use lining that will seal underlying dentine, but avoid blocking out retention grooves Alternatively, seal cut dentine with a dentine bonding agent (immediate dentine seal) Apply metal matrix band and wedge Restore with amalgam and carve Alternatives Traditional MO/DO (mesio-occlusal/disto-occlusal) amalgam Much operative dentistry involves the replacement of previous restorations If preparation involves an occlusal lesion giving MO/DO cavity then additional approximal retention grooves are unlikely to be needed Tunnel preparation • Aims to preserve marginal ridge by approaching approximal caries more obliquely • Main advantage is that overall strength of tooth is preserved • Cavity usually restored with a glass ionomer/cermet base and ‘occlusal’ composite • Technically difficult and needs magnifying loupes to prepare • Concerns over ability to clear ADJ of caries coronally • Fracture of marginal ridge long term, particularly in premolars. Direct access • Only restore when preventive approaches fail to arrest caries • Treat as for smooth surface caries (Class V). 528 • C L I N I C A L D E N T I S T RY Class III cavity – composite resin • • • • • • • • • • • • • • • • Cavity preparation Preferably use palatal/lingual approach as buccal enamel left intact Use labial approach only when direct access is possible (due to anterior tooth crowding) Remove friable enamel, but leave unsupported enamel as this will be supported by composite Restoration placement Pretreat cavity surface with acid etching of enamel/dentine bonding/ application of unfilled resin Place matrix strip so that it extends below contact area Adapt matrix to cervical margin as this is area where excess composite is difficult to remove Matrix supported palatally/lingually by finger and material placed/injected into cavity Once restoration placement complete, strip is moved over labial surface and material cured May need to use wedge for closer cervical adaptation Finishing and polishing Excess can be removed by hand instruments/composite finishing burs Series of graded polishing discs, cones or cups are useful in gaining aesthetic polish Contact areas may be finished using graded interproximal finishing strips Final gloss can be added with polishing cream/diamond polishing paste Alternative Large or aesthetically critical cavities can be restored using a ‘composite resin layering’ technique. Many manufacturers produce composites with a large range of dentine and enamel shades. Restore the bulk of the missing dentine with dentine shade composite. Restore the remainder of the cavity using enamel shades with a matrix strip. Layered build-up can be facilitated by using a putty matrix developed from a diagnostic wax-up. Class IV cavity Class IV cavities are usually caused either by trauma or the collapse of a large interproximal lesion affecting an anterior tooth. Tooth wear can also produce ‘Class VI’ lesions affecting the entire incisal edge. • • • • • Cavity preparation May need little or no preparation A long labial ‘wavy’ bevel may help with retention and allow the composite and tooth to blend together naturally, and avoid unsightly transition lines. Restoration placement Pre-treat cavity surface with acid etching of enamel/dentine bonding/ application of unfilled resin O p erati v e dentistry • • • • • • • • 529 Place matrix strip so that it extends below contact area Alternatively use a pre-formed transparent matrix. Adapt matrix to cervical margin carefully as this is the area where excess composite is difficult to remove Apply composite in 1–2 mm thick increments and cure from both labial and palatal aspects Use matrix to apply final increment Finishing and polishing As for Class III (p. 528) Alternative technique Where there is extensive loss of tooth tissue an alternative approach is to carry out a diagnostic wax-up on a plaster model. A silicone putty matrix is made using a small sausage of impression putty, adapted to the palatal surface of the wax-up and just up to the incisal edge. This matrix is then used to provide support while the palatal surface of the composite restoration is developed. Once this has been completed, the remainder of the restoration can be ‘filled in’ by hand, using clear interproximal strips. Class V cavity (cervical caries) • • • • • • Only restore when preventive approaches fail to arrest caries Access lesion; extend until the ADJ is caries free Gingival margin outline often subgingival May need gingival retraction paste or cord/radiosurgery to control haemorrhage or gain adequate subgingival access and soft tissue control Many alternative restorative materials can be used including amalgam, composite, conventional GIC, resin-modified GIC and compomer Clinical trials suggest that GIC has greatest longevity. Core restorations Badly broken down teeth may require an extensive multisurface restoration known as a core. These often provide the foundation for a crown, as the remaining natural tooth substance is severely compromised and requires protection against occlusal loads and potential fracture. Various types of cores can be used depending on whether the tooth is vital or is root filled: Vital teeth Slots and grooves Slots and grooves approximately 1–2 mm deep can be placed in sound, caries-free dentine. Restorative materials can lock into these to provide additional retention and resistance form. 530 • C L I N I C A L D E N T I S T RY Adhesive approach Dentine bonding agents can be used to provide additional retention for composite restorations and similar resin adhesives are available for bonding amalgam. An alternative approach is to use setting resin adhesives as a lining material during amalgam restoration; this will bond to enamel and dentine and the technique involves packing amalgam directly onto unset resin adhesive (Baldwin-type technique). As the amalgam is placed it will exclude oxygen and the adhesive will set. Dentine pins Either stainless steel, titanium or gold plated. Pins are threaded, selftapping, and the pin hole is slightly smaller than the diameter of pin so that the elasticity of dentine holds the pin. Many clinicians now try to avoid dentine pins wherever possible, as pulpal exposure or perforation into the periodontal ligament is an ever present threat. However, dentine pins are a useful retentive aid in the severely broken down tooth. Technique • • • • • • Pin should be placed in the largest bulk of sound dentine available, not at ADJ (enamel will craze and chip); usually place 1 mm inward from ADJ Use low revs and water coolant during pin hole preparation Pin must not be placed in pulp or PDL (Periodontal Ligament; knowledge of dental anatomy essential) If using more than one pin they should be as far apart as possible Pins may be bent towards centre of restoration, after placement Correct packing of restorative material around pins is essential to develop retention. Root-filled teeth Nayyar core/Coronal-radicular amalgam core. Used for core placement in root-filled premolar and molars. Technique. remove coronal gutta-percha to a depth of 3–4 mm and place restorative material into coronal pulp chamber before building up rest of core. Produces a homogeneous core-retention system. Post crowns – see page 539. Choice of restorative material The following is offered as a guide: Amalgam Large/multisurface restorations in molar teeth (high occlusal loads) Repair of existing amalgam restorations Cores O p erati v e dentistry • 531 Composite Fissure sealants Class I and II restorations in posterior teeth Class III restorations Class V restorations in aesthetically critical areas Class IV restorations (consider layering techniques) Cores Conventional glass ionomer cement Root caries Class III restorations in high caries risk patients (e.g. hyposalivation) Class V restorations Compomers Non-carious cervical lesions Resin modified glass ionomer cement Liners and bases Luting cements. Class V restorations. Management of the deep carious lesion A deep carious lesion occurs when caries lies in close proximity to the dental pulp. When a cavity is considered deep but the pulp is not exposed, hard stained dentine may be left over the pulpal area. Removal of this frequently results in pulpal exposure. Techniques for management of the deep carious lesion Indirect pulp capping The objective of this technique is to protect the pulp from bacterial contamination via a pulpal exposure. A pulpal exposure is recognized by pulpal haemorrhage. It must be noted that a microexposure may be present. Therefore the classic bleeding exposure is a relatively severe pulpal wound. Deep cavities should be managed under rubber dam to decrease bacterial contamination of micro-exposures, pulpal exposures or carious exposures (p. 533). Technique Indirect pulp capping should be used for all cavities where it is considered there may be a micro-exposure or where removing further remnants of caries is likely to cause classic pulpal exposure. A layer of tricalcium silicate cement or traditional setting calcium hydroxide is placed over the dentine closest to the microexposure. This is reinforced by a structural lining. 532 • C L I N I C A L D E N T I S T RY Direct pulp capping An exposed healthy vital pulp may be pulp capped. Less successful than indirect pulp capping. Direct pulp capping is most likely to succeed when: pulpal exposure is small (<1–2 mm); pulp is free of salivary contamination; carious exposure is not present (pulp already likely to be chronically inflamed); tooth was symptom free prior to cavity preparation (less initial pulpal inflammation); patient is young (better pulpal blood supply). Technique Haemorrhage is arrested with a sterile paper point or cotton-wool ball. Cavity cleaned with sterile saline or sodium hypochlorite. Tricalcium silicate cement (ie. MTA; Mineral trioxide aggregate) or calcium hydroxide flowed over exposure and allowed to set. Structural lining can be placed, but usually not over tricalcium silicates. Mode of action of tricalcium silicate based cements in pulp capping. The family of tricalcium silicate cements has a variety of actions in the process of pulp capping: Antibacterial action. Tricalcium silicate cements are alkaline when hydrated, and release alkaline products which have an antimicrobial action. Remineralization. The tricalcium silicate cements release calcium ions and form hydroxyapatite when hydrated and in contact with pulpal tissue fluids. Reactive dentinogenesis. The tricalcium silicate cements induce highly organized neodentine formation and maturation. Organized dentinal tubules are seen within the reparative dentine tissue and there is no inflammation. These materials promote regeneration rather than tissue repair. Low porosity. The tricalcium silicate cements are homogenous materials with reduced leakage and very low porosity. Mode of action of calcium hydroxide in pulp capping. Calcium hydroxide has several actions in pulp capping: Antibacterial action. Calcium hydroxide can render demineralized dentine sterile via its inherent antibacterial activity due to its high pH, although it is quickly neutralized. Remineralization. Calcium hydroxide is involved in the remineralization of carious dentine via the activation of alkaline phosphatases, and it neutralizes lactate from osteoclastic activity. Reparative dentine formation. In the pulpal tissue adjacent to calcium hydroxide there is a 2 mm deep zone of pulpal necrosis followed by repair. This is by formation of atubular reparative osteo-dentine, which is disorganized, highly porous and contains tunnel defects. O p erati v e dentistry • 533 Carious exposures A carious exposure means that the exposed pulp is contaminated with bacteria and essentially undergoing a chronic inflammatory process. The treatment of choice for a carious exposure is removal of the pulp and conventional root canal treatment. Use of corticosteroid–antibiotic preparations in management of the deep carious lesion. Corticosteroid–antibiotic pastes have been used for many years to relieve acute pain associated with deep carious lesions and facilitate local anaesthesia of acutely inflamed dental pulps. Mode of action: anti-inflammatory. (from the steroid) and bacteriocidal/ bacteriostatic (from the antibiotic). Useful when there is a hyperaemic pulp and failure of local anaesthesia; most commonly when there is an irreversible pulpitis and/or carious exposure. Use of these pastes may cause relief of symptoms, decreased inflammation with the ability to successfully anaesthetize the tooth on the next occasion. Pastes containing tetracycline-based antibiotics (eg. Ledermix) should not be used for patients under the age of 12 years. It is imperative to realize that once these pastes have been used, conventional root canal treatment must thereafter be performed on the tooth. Use of these materials as a long-term indirect or direct pulp cap is not advised. Alternative cavity preparation techniques Alternative methods of cavity preparation have recently been introduced in the form of ultrasonic and air abrasion techniques. Ultrasonic preparation This technique uses the vibration of a series of diamond-coated sonic tips to remove tooth tissue. Some tips are coated on one side to allow preparation of approximal cavities without damaging the adjacent tooth. Ultrasonic preparation is also employed in endodontic treatment. Air abrasion Tooth preparation is undertaken using aluminium oxide particles (20–50 µm) delivered via a small-diameter nozzle at 240–960 kPa (40–140 psi). Useful for the preparation of pits and fissures, as this technique produces saucer-shaped cavities that are ideal for restoration with composite resin and other adhesive materials. Preparation 534 • C L I N I C A L D E N T I S T RY needs to be carried out under rubber dam and using high-volume suction to minimize the spread of the aluminium oxide dust. Crowns A crown is a restoration that encompasses coronal tooth tissue, covering remaining tooth substance and restorations. When insufficient tooth tissue remains, the root canal can be used to aid retention – a post-retained crown. Types of crowns Full coverage. Full-veneer crowns (usually made of gold or nonprecious alloy for posterior teeth); traditional porcelain jacket crowns (anterior teeth); metal ceramic crowns; all-ceramic crowns; indirect composite resin crowns; resin-ceramic crowns. Post-retained crowns. Cast gold post and core; cast non-precious alloy post and core; prefabricated post and direct core. Partial coverage. Three-quarter crowns and reverse three-quarter crowns. Assessment of teeth for crowns Case selection is important. In order to plan treatment appropriately, when considering crowns, assess: tooth vitality; periodontal support and gingival condition; oral hygiene; caries control; occlusion; radiographic appearance; aesthetics (including patient’s expectations); adjacent teeth. In some cases study casts, clinical photographs and a diagnostic wax-up of anticipated appearance may be useful. Clinical stages in making crowns 1. Shading and surface characteristics All-ceramic, metal-ceramic, resin-ceramic and indirect composite resin crowns will require careful assessment and selection of tooth shade, degree of translucency and the extent of surface characteristics, such as wear facets, indentations, and surface textures. These features can be gleaned from surrounding natural teeth or restorations, and also the patient’s expectations. This process must be performed before preparation or desiccation of the tooth. In tooth discoloration cases, shading of the crown preparation (‘stump’ shade) can also be performed intra-operatively. 2. Preparation Crown preparation involves removal of enough tooth substance allowing sufficient thickness of material (from which the crown is to O p erati v e dentistry • 535 be made) to provide strength and aesthetics. Preparation must not damage the pulp. Preparation must provide sufficient retention for the crown. This can be achieved by taper of 5–20° (especially in cervical third of preparation), and inclusion of retention grooves or slots is useful in teeth of reduced occlusogingival height. Preparation should involve minimal gingival trauma. Preparation should have smooth curves, not right angles or sharp edges. Finishing lines depend on the material from which the crown is to be made. Options for finishing lines: • • • • • Butt Joint Shoulder, e.g. porcelain jacket crown, labial ceramic margin of a metal-ceramic crown. Rounded Shoulder, e.g. all-ceramic crown, resin-ceramic crown. Bevelled shoulder, e.g. labial ceramic with metal collar margin of metal-ceramic crown. Chamfer, e.g. palatal metal margin of a metal-ceramic crown, dentine-bonded crown. Taper or knife-edge or feather-edge, e.g. full-veneer gold crown or non-precious alloy crown. Preparation is usually achieved by a selection of high-speed diamond burs. 3. Temporization/Provisional crown Prepared teeth require temporization for aesthetics, pulpal protection and prevention of overeruption or drifting of opposing or neighbouring teeth. Types of provisional crowns Anterior teeth. Polycarbonate preformed crowns; polyethylmethacrylate or composite-based resin crowns fabricated using an alginate impression or putty matrix. Posterior teeth. Stainless steel; polycarbonate; polyethylmethacrylate; composite-based resin. Usually provisional crowns are cemented with temporary cement. Occasionally, a more permanent luting cement may be used when the temporary crowns are to be worn for a prolonged period or preparations are of reduced occlusogingival height. Laboratory-made provisional crowns may be constructed if temporization is for a prolonged period. 4. Impression An accurate impression of the preparation is essential if the crown is to fit. Materials used in crown impressions include polyvinylsiloxane, polyether, polysulphide (usually with an individual tray) (Chapter 11). 536 • C L I N I C A L D E N T I S T RY To ensure an accurate impression: • • • • • • • • Follow the manufacturer’s instructions for the particular impression material selected. Good moisture control is essential as most impression materials have a degree of hydrophobicity. Obtain gingival retraction where a preparation is subgingival via use of retraction paste, an appropriate thickness of retraction cord or occasionally using radiosurgery. Examine the set impression very critically, paying particular attention to air blows, voids, tears and shiny surfaces (lack of flow of impression), and repeat if necessary. In difficult cases use of impression copings or proceeding to a trial of a casting may ensure a satisfactory end result. An impression of the opposing arch in irreversible hydrocolloid or polyvinylsiloxane is required. Jaw registration is essential and is usually achieved by ‘best fit’ when sufficient teeth are present. Polyvinylsiloxane or silicone registration materials are recommended if ICP (intercuspation position) is unstable, unreproducible or if opposing tooth numbers are reduced. Wax or reinforced wax is dimensionally unstable and should not be used. Record blocks may be required for large saddle areas. Use of a facebow for mounting the upper model on a semiadjustable articulator is often desirable, especially if the restored tooth is involved in mandibular guidance or as part of a ‘slide’. 5. Prescription for technicians The dentist should communicate information about crown shape, shade, irregularities and design (e.g. type of margin, type of material, rest seats/undercuts/guide planes) clearly to the technician. The technician must also be informed of the luting agent/bonding agent to be used at crown fit. 6. Cementing/Bonding a crown On receipt of a crown from the laboratory check that: the cast has been trimmed correctly – compare impression margin and cast margin; the neighbouring teeth on the cast have not been abraded; the crown fits the cast and duplicate cast (if present); the correct design features are present; the occlusion is correct; the shade looks broadly correct. The provisional crown should be removed from the mouth and any adherent temporary cement removed via gentle ultrasonic cleaning (often this requires local anaesthetic). The definitive crown is tried in. The following should be carefully checked: O p erati v e dentistry • • • • • 537 Marginal fit. Contact point with neighbouring teeth. This should be such that interdental cleaning is facilitated, and food trapping is prevented. Gingival emergence profile. Occlusion in all mandibular movements. When the dentist is satisfied, the patient should be shown the crown aesthetics and modifications made if required. When both dentist and patient are satisfied, the preparation is degreased (with alcohol), dried and the crown cemented with a permanent luting cement or bonding system. If there is any doubt, it is prudent to use a temporary luting cement and review the situation. Excess cement must be removed from around the crown margin. The patient should be given oral hygiene instruction regarding the crown. Common faults with crowns Despite careful attention to detail the following faults with crowns can occur: Overhanging margin. Arises from inadequate tooth preparation, poor impression, poor technical work, or a combination. Can in some cases be corrected by trimming with a bur, but often requires a remake. If uncorrected leads to plaque accumulation, gingival or periodontal inflammation or recurrent caries. Negative margin. Usually due to poor finishing line delineation, over-trimming of die or over-vigorous polishing of crown margins. Patient often feels sensitivity. Risks recurrent caries or poor aesthetics. Poor gingival emergence angle. Usually due to poor communication between dentist and technician. Overbulking of material at the gingival margin leads to plaque accumulation. Poor contact point. Usually due to under-preparation of mesial and distal walls, excessive trimming of the master die and adjacent model or overbulking of interdental area by technician. Hinders interdental cleaning. Poor aesthetics. Can be due to incorrect shade, shape or underpreparation leading to insufficient space for material. Occasionally patients have unrealistic expectations or there may be a lack of patient communication by the clinician. Persistent debonding. Often due to inadequate retention form or resistance form on preparation. May be due to occlusal interference (especially lateral excursion). In post-retained crowns may be due to poor post design or longitudinal root fracture. 538 • C L I N I C A L D E N T I S T RY Anterior crowns Indications. Protection of heavily restored teeth; aesthetics; conventional bridge retainer; tooth wear. Types of anterior crowns Metal–ceramic crown. Used when limited occlusal space and high functional loads. Relies on the ability of porcelain to bond to metal oxide. Modern metal–ceramic crowns have excellent aesthetics. Can have metal (when very limited occlusal space) or porcelain palatal surface. Often have butt joint labially (1.5 mm shoulder to allow adequate metal and porcelain for aesthetics) and chamfer margin palatally. A typical metal–ceramic crown preparation for an anterior tooth is shown in Figure 19.3. Porcelain jacket crown. Traditionally used when aesthetics of prime concern but have gone out of fashion as employs feldspathic porcelain. Problem in high-load situation as porcelain in thin section and liable to fracture; not usually suitable for posterior teeth. Usually butt joint shoulder around whole preparation (minimum 1 mm shoulder to allow adequate porcelain for aesthetics). Need 1.5 mm thickness of porcelain incisally. All-ceramic crowns. All-ceramic crowns with superior aesthetics and with higher tensile and compressive strengths than conventional porcelain jacket crowns are finding increasing use. One group incorporate fillers in the glass ceramic, and they are leucite-reinforced, lithium disilicate-based, or glass infiltrated. These are highly aesthetic and acid etchable with strong acid, i.e. hydrofluoric acid. The other group employ sintered alumina or zirconia cores with matched Note: rounded preparation, i.e. no sharp angles Gingivae Cervical 1/3 forms retentive collar Chamfer palatal margin for metal (usually supragingival) Tooth 1.5mm labial shoulder for porcelain Crown 2–2.5mm incisal reduction Lateral view Figure 19.3 Metal–ceramic crown preparation of upper anterior tooth. O p erati v e dentistry Preparation finished supragingivally palatally • 539 Note: rounded preparation, i.e. no sharp angles Gingivae Cervical 1/3 forms retentive collar 1.5 mm labial shoulder Tooth 1.5 mm palatal shoulder Crown 2 mm incisal reduction Lateral view Figure 19.4 All-ceramic crown preparation of upper anterior tooth. feldspathic veneering ceramic. These all-ceramic crowns are very strong but less aesthetic. CAD-CAM (https://en.wikipedia.org/wiki/ CAD/CAM_dentistry) technology has also revolutionized the design and manufacture of the all-ceramic crown. All-ceramic crown preparations require even reduction; preparation similar to a conventional aluminous porcelain jacket crown, except internal and external line angles must be rounded. Minimum reduction of 1.5 mm is required. Use of dentine-bonded crowns and reverse three-quarter crowns involve significantly less tooth destruction. A typical all-ceramic crown preparation for an anterior tooth is shown in Figure 19.4. Post retained crowns Indications. When there is insufficient coronal dentine to withstand occlusal forces or retain a crown. Root dentine is used and loads transmitted via a post to the root dentine. The post retains the crown. Usually root-filled teeth (but not every root-filled tooth requires a post crown). A circumferential 1.5 mm natural tooth tissue ferrule is required even with the use of a post-core system. Assessment of teeth for post crowns. Careful assessment of individual teeth is required before considering a post crown. Root length. A long post is favourable for crown retention and a post extending to within 4–6 mm of the root apex is ideal. Root length may vary due to apicectomy, resorption, fracture. Root width. A wide post is often desirable; however, teeth such as first premolars or lower incisors are often extremely narrow and a wide post would leave such a tooth very weak. Root alignment. Curves and dilacerations complicate post design. 540 • C L I N I C A L D E N T I S T RY Root canal filling. A sound root canal filling must be present (leave 4 mm) with no apical pathology evident before post placement. Problems with post crowns Failed post crowns are a common occurrence. Problems include: Root perforation. Occurs after failing to judge root alignment. More common with engine-driven instruments. Root fracture. Occurs particularly with wide posts (in high occlusal load situations) where root dentine is excessively weakened. Post debonding. Occurs especially with short, tapered posts. Likely with high occlusal load or root fracture. Fractured post. Thin cast posts are susceptible to fracture due to occlusal loads or trauma. Removed with ultrasonic vibration, a proprietary post-removal system or less commonly a trephine system. Non-metallic silica-fibre posts can be removed by drilling between the longitudinal fibres. Corrosion. Can be a problem if core and post are made of dissimilar metals. Types of post crowns A multitude of post crown systems exist. There is no single post core system that is suitable for all situations. Basic types. Cast post core systems; prefabricated post core systems. Within these systems, posts may be parallel sided, tapered, threaded, serrated or parallel pins. Cast post core systems. Usually made of cast gold or non-precious alloy, i.e. NiCr, but rarely nowadays wrought gold post and cast gold core. Problems involve casting porosity. Used successfully for many years. Tooth preparation should preserve as much coronal dentine as possible. Resist rotational forces by means of anti-rotational grooves or parallel pins. Post hole preparation should ideally be achieved with hand instruments to avoid risk of perforation. Impression techniques may be indirect or direct: Indirect. Involves use of wire or preformed plastic in the canal and an impression in an elastomeric impression material. An opposing arch impression and jaw registration is taken and the post core waxed up in the laboratory, invested and cast. It is not recommended to construct a post core and final crown using a single impression. Direct. Involves use of a plastic post and either inlay wax or self-cured acrylic, modelled at chairside to gain an impression of the post hole and core shape. This is then invested and cast in the laboratory. Advantage – clinician has control over core shape. O p erati v e dentistry • 541 Prefabricated post core systems. These may be subdivided into: post and integral core; post (core built in plastic restorative material). Wide range of materials are in use – stainless steel, brass, titanium, nickel–chromium, ceramic, carbon-fibre, composite-silica fibre. Advantages. Can be placed directly, so avoiding laboratory stage; material properties often superior to cast gold; easy to use; immediate coronal seal of root canal system. Disadvantages. Increased clinical time; preparation often involves mechanical instruments so increased risk of root perforation or fracture; often designed for ‘average’ teeth so do not meet needs of teeth with wide or narrow root canals; failure of core (if made in plastic restorative material). When using prefabricated post systems, the dentist should bear in mind the individual manufacturer’s recommendations, the limitations of the particular system and the core material to be employed. Core materials. Composite resin, amalgam or resin-modified glass ionomer. Use of autocured or dual-cured materials is important so that restorative material is properly set (Chapter 11). Clinical tips The ‘first bite of the cherry’ principle. Post crowns are most suc­ cessful the first time they are constructed on a particular tooth. Treating failures is difficult as the preparation is already compromised. If fortunate to have the ‘first bite of the cherry’ in post crown treatment ensure: as much coronal dentine as possible is maintained; post of adequate length and width to enhance retention but not compromise root strength or apical seal of root canal filling; there is adequate resistance to rotational forces in the preparation (anti-rotation element); final crown design is known at the outset in order that core can be designed properly; if using an indirect cast post system, instructions on design are clearly communicated to technician. Cementation/Bonding. Luting failures are common. The tooth should be dried. A spiral paste filler should be used to transport conventional luting cement into the canal and to coat the walls; further luting cement is placed on the post and the post core firmly seated. Bonding posts into prepared post spaces requires adequate intracanal etching, moisture control and curing. Dentine bonding agents and dual cure resins are common. Variations Posterior teeth. In molars and some premolars, roots are often narrow and at differing angulations leading to an increased risk of perforation or fracture by use of posts. Therefore use only posts essential for core retention. Consideration should be given to the use of 542 • C L I N I C A L D E N T I S T RY dentine pins or packing of plastic restorative materials into root canal orifices to enhance core retention (so-called amalgam ‘post’/Nayyar core). Diaphragm. Where there is subgingival root fracture, the use of a cast post core and diaphragm may be appropriate. Angulated teeth. Minor tooth angulation problems, e.g. retroclined individual tooth, may be corrected by altering core angulation within the confines of occlusal harmony. Apicected teeth. Often have fairly short roots; thus post retention may be particularly difficult. Consideration should be given to making the final restoration non-functional. Posterior crowns Indications. Aesthetics (some posterior teeth only); bridge retainer; tooth wear; protection of heavily restored teeth; partial denture abutments. Types of posterior crowns Metal–ceramic crown. Used when insufficient occlusal space, high functional loads, or aesthetics important. Metal (when limited occlusal space) or porcelain occlusal surface. Junction of metal and porcelain should not be in area of high occlusal stress. Can have metal or porcelain (superior aesthetics) labial margin. Often have butt joint labially (1.5 mm shoulder to allow adequate metal and porcelain for aesthetics) and chamfer margin palatally or lingually. Functional cusps (in Class I occlusion upper palatal cusps and lower buccal cusps) need additional tooth reduction (extra 0.5 mm) by means of a functional cusp bevel. A typical metal–ceramic crown preparation for a posterior tooth is shown in Figure 19.5. 1.5 mm occlusal reduction Functional cusp bevel Lingual chamfer margin Tooth 1.5 mm buccal shoulder Gingivae Distal view Figure 19.5 Metal–ceramic crown preparation on lower molar with porcelain labial shoulder and metal lingual shoulder. O p erati v e dentistry 1mm occlusal clearance Crown (1.5mm on functional cusp) Margins supragingival where possible Tooth • 543 Functional cusp bevel Chamfer margin Gingivae Distal view Figure 19.6 Full-veneer crown preparation on lower molar. Full-veneer crown. Used when aesthetics of minimal concern (usually second or third molars). Usually made of cast gold. Tooth preparation should be as conservative as possible with the following features: buccolingually and approximally, a 5° taper is ideal; chamfer margin removing all undercut areas. Should finish supragingivally – not always possible as preparation should extend more gingivally than existing restorations so that preparation finishes on sound dentine. Require minimum of 1 mm reduction occlusally to allow for gold to cover preparation. Functional cusp bevel is needed to allow more occlusal clearance (1.5 mm) over functional cusps. A typical full-veneer crown preparation for a posterior tooth is shown in Figure 19.6. Other posterior crowns. Cast gold partial-veneer crowns such as three-quarter crowns are occasionally useful to preserve a single intact cusp (usually mesiobuccal cusp of upper first molar). Allceramic crowns with sintered alumina or zirconia cores are finding increasing use in posterior crown situations, as are castable glass ceramics. Veneers A veneer is a facing placed on either the labial or palatal surface of a tooth. Types of veneers Labial veneers; palatal veneers; adhesive/dentine-bonded crowns. Labial veneers Uses. Aesthetic improvement of discoloured teeth; closure of diastemas; reshaping of hypoplastic teeth (e.g. peg laterals); aesthetic 544 • C L I N I C A L D E N T I S T RY masking of minor tooth position problems (e.g. slightly in-standing tooth); trauma to anterior teeth; very rarely, as a bridge retainer in low occlusal stress situations. Materials. Porcelain laminate veneers; direct composite veneers; indirect composite veneers. In modern fixed prosthodontics, the porcelain laminate veneer is most commonly used as a labial veneer. Sometimes composite resin veneers may be used following trauma (usually in children until gingival margin stabilizes at around 18 years), and increasingly direct composite resin labial veneers are being used as a medium-term solution to improve appearance. Case selection. Existing caries, periodontal disease, occlusion and endodontic status should be assessed. Often porcelain laminate veneers are provided for aesthetic reasons so patient expectations should be determined preoperatively. Teeth with large mesial or distal plastic restorations are usually not suitable for veneers due to increased risk of recurrent caries. Tooth wear and parafunctional habits should be assessed; veneers are often ill advised in such situations or may need a protective occlusal splint. Smile lines should be determined to identify which teeth require veneers. Types of laminate veneer preparation (Figure 19.7) Intra-enamel. A localized area within the labial surface of a tooth. Often requires minimal preparation. Feathered incisal. This preparation involves 0.5–1 mm reduction on labial surface with chamfer margins approximally, incisally and at gingival margin. There is no incisal overlap. Intra-enamel preparation Feathered incisal preparation Lateral view maxillary incisors Figure 19.7 Porcelain laminate veneer preparations. Overlapping incisal preparation O p erati v e dentistry • 545 Overlapping incisal. As for feathered incisal, except that there is 1 mm of incisal reduction and the incisal edge is overlapped. No preparation. Sometimes (often interim measure in children) there is no preparation. This, however, leaves an over-contoured tooth. Clinical stages 1. Shading and preparation • • • Following careful shading, the appropriate type of preparation is chosen and undertaken with an air turbine and a selection of fine grit diamond burs. Usually in enamel only and so local anaesthesia is not required. With the improved performance of dentine bonding agents, veneers are being used on teeth with exposed dentine so increasingly veneer preparations extend into dentine. 2. Impressions Usually performed in an elastomeric material with alginate impression of the opposing arch. 3. Temporization Temporary veneers are usually not required. Patients should be warned of some postoperative sensitivity and poor aesthetics. A putty matrix taken of a diagnostic wax-up can be used to produce provisional veneers. 4. Bonding The finished veneer should be tried in and checked for occlusion, fit and aesthetics. • • • • • • • • • Isolate tooth. Try in veneer with water-based try-in paste and assess appearance, fit and occlusion. When satisfied, clean fitting surface of veneer and etch with hydrofluoric acid. Apply silane coupling agent to fitting surface of veneer. Place matrix strip or PTFE tape mesially and distally. Enamel is etched with 37% phosphoric acid. Composite luting cement is placed on veneer and veneer seated. Use dual cure cement if veneer is very thick. Remove excess material with a brush and light-cure. Remove any remaining cement flash and check interdental contacts. Note: Where there is dentine present labially, a suitable dentine bonding agent should be used. Life span: 10 years plus; 5% prone to chipping around incisal edge. 546 • C L I N I C A L D E N T I S T RY Alternative Direct placement composite veneer. Usually used as medium-term restoration in adolescents until level of gingival margin stabilizes at around 18 years of age, or in adults as a medium term cost-effective solution, which is reversible, conservative of tooth tissue and easy to maintain. Preparation. Either no preparation or as for ceramic veneer. Acid etch and place directly using plastic matrix strips/PTFE tape to protect adjacent teeth. Life span 3–7 years; more prone to chipping and discoloration, but can be polished and refurbished easily. Palatal veneers Facings on the palatal surfaces of upper anterior teeth only. Uses. Tooth wear (in particular acid erosion); decrease dentine sensitivity; restore aesthetics; protect pulp; act as ‘Dahl’ appliance. Can extend onto worn incisal edge to improve appearance. Types Direct composite veneers. Primary treatment method in tooth wear cases. Easy to place, adjust and repair. Can be extended onto worn incisal edge to improve appearance. Can be placed ‘high’ in occlusion using Dahl approach (minor axial tooth movement) and posterior teeth allowed to erupt back into contact (approx. 3–6 months). Commonly used as they are easy to repair. Gold palatal veneers. Previously required oxidized fit surface (400°C for 3–5 min) to provide copper oxide layer that bonds with metal-active adhesive. Modern adhesives do not require an oxidized surface, just a grit-blasted fit surface. Can be very thin. Poor if translucent incisal edge present as metal shines through (but better aesthetically than nickel–chromium). May have a role in deep overbite cases. Nickel–chromium backings. Can be very thin. Poor if translucent incisal edge is present as metal shines through. Better mechanical properties than gold. Useful if attrition is the main cause of tooth wear. Ceramic palatal veneers. Should be about 1 mm thick. Rarely used due to concerns about long-term wear effects on opposing lower incisors and high chance of ceramic fracture. O p erati v e dentistry Proximal reduction to just beyond contact point Palatal finish 1mm incisal to centric contact and 1.5 mm gingival to incisal edge of preparation • 547 1–1.5mm labial reduction 1.5mm incisal reduction Lateral view maxillary incisor Figure 19.8 Adhesive/dentine-bonded crown. Adhesive-/Dentine-bonded crown Has features of both a porcelain laminate veneer and a traditional porcelain jacket crown. This restoration involves enamel reduction labially, approximally and incisally and from the incisal quarter of palatal or lingual surfaces. All finishing lines are a heavy chamfer to enable a rounded butt joint with the feldspathic porcelain (Figure 19.8). Uses. Fractured incisal edges; closure of diastemas; discoloured teeth; labial caries; alternative to conventional crowns in lower anterior teeth. Advantages Advantages over porcelain laminate veneer. Greater strength; larger area for retention; less overbulking gingivally; potentially improved aesthetics; more accessible approximal margins. Advantages over porcelain jacket crown. More conservative of tooth tissue; decreased gingival problems; less abrasion of opposing tooth; some exposed dental tissue available for future vitality testing. Disadvantages. Adhesive crowns may fracture under high occlusal load, e.g. parafunctional habits or canine teeth. Common problems with veneers include. Poor gingival emergence angle; fracture in function; fracture on cementation; poor interdental contact; aesthetics not ideal (especially if need translucent incisal tip); lack of positive seating on cementation so cemented incorrectly. Inlays and onlays Inlays Inlays are intracoronal restorations which are manufactured in the laboratory and cemented into place. 548 • C L I N I C A L D E N T I S T RY Types. Gold inlays; composite inlays; ceramic inlays. Uses. Main use is in Class II cavities. Historically gold inlays have had limited use in Class III and Class IV cavities. Advantages. Offer an alternative to amalgam as an intracoronal restoration; protects weakened cusps (cuspal coverage); more aesthetic than amalgam (composite and ceramic have superior aesthetics). Disadvantages. Require two clinical stages and one laboratory stage; increased tooth tissue destruction to achieve a non-undercut cavity; microleakage and recurrent caries can be a problem; gold inlays may result in galvanic reaction if amalgam in opposing or adjacent teeth; radiographic marginal diagnosis not easy with composite or porcelain inlays as they are less radio-opaque than metal. Clinical techniques. In all inlays the usual features of cavity design should be followed; that is, caries removal, retention and resistance form. Linings and structural linings should be placed as they would be for a plastic restoration. Gold inlays 1. Preparation Cavity must ensure a path of insertion and removal of inlay (5° ideal taper). Margins usually a fine taper or chamfer. Often need to cusp protect, i.e. cover functional cusps. If retention is poor, additional retention by means of parallel pins (pinlays) may be incorporated. 2. Impressions Indirect. Involves an impression in an elastomeric impression material. An opposing arch impression and interocclusal registration is taken and the inlay waxed up in the laboratory, invested and cast. Direct indirect. Involves use of either inlay wax or self-cured acrylic. The dentist models self-cure acrylic or inlay wax to gain an impression of the inlay cavity and models the inlay shape. This is then invested and cast in the laboratory. 3. Temporization Inlay temporization is difficult, particularly if fine chamfer margins exist. The usual temporary crown materials (Chapter 11) are used but are not ideal. In some cases a temporary restorative material such as Zinc Oxide–Eugenol (ZOE) or coloured GIC may be used. ZOE based provisional restorations must not be used if adhesively bonding the inlay. O p erati v e dentistry • 549 4. Inlay insertion Once fit, occlusion and contact points have been checked, the inlay is adjusted and polished; it may be cemented with a conventional luting cement, e.g. polycarboxylate. With the advent of improved alloy bonding systems, grit-blasting the inlay, and bonding with dual or autocured resin composite, is very popular. Composite inlays 1. Preparation Cavity taper wider than gold (15–20°). Cuspal coverage not usually required. Chamfer margins not required. Where possible, margins should be supragingival and based on enamel to reduce microleakage and optimize marginal bond strength. 2. Impressions An indirect technique as for gold inlays is used. In the laboratory, inlays are heat-, pressure- or light-cured (or a combination of these methods) depending on individual manufacturer’s recommendations. 3. Temporization Similar to gold inlays. 4. Cementation a. Enamel etched. b. On dentine, a suitable dentine bonding agent should be used and light-cured (follow manufacturer’s recommendations). c. Unfilled resin/dentine bonding agent is placed on enamel, excess blown off with air and light-cured. d. Unfilled resin is placed on inlay, excess blown off with air and light-cured. e. Filled dual-cured resin is placed on inlay and inlay seated. f. Optional seating using ultrasonic scaler for 30 seconds (special tips); gives improved seating. g. Excess flash removed before light curing. h. Any remaining flash is removed and interdental contacts checked. Porcelain inlays 1. Preparation Similar to composite inlays except that a butt joint is required; therefore greater destruction of tooth tissue. 550 • C L I N I C A L D E N T I S T RY 2. Impressions An indirect technique as for gold inlays is used. In the laboratory, inlays are waxed up and injection moulded/pressed ceramic can be used. There is increasing manufacture of inlays by both CAD-CAM technology and using sintered alumina or zirconia blocks. 3. Temporization Similar to gold inlays. 4. Cementation Similar to composite inlays except that the fitting surface of the inlay is often etched with hydrofluoric acid and silane coupled prior to application of unfilled resin. Zirconia may have a glazed fit surface to enable etching and bonding. Onlays Onlays are extracoronal restorations on the occlusal surface of a tooth. Types. Gold onlays; composite onlays; porcelain onlays. Uses. In tooth wear cases they are a less destructive alternative to increasing vertical dimension of occlusion than crowns. (Note: In severe attrition cases may not withstand parafunctional forces.) Also used for arrested caries, fractured cusps. Onlays often require minimal tooth preparation and are supragingival. The composite/porcelain onlay, however, requires a butt joint so a shoulder of 0.5 mm or more is often needed. Clinical techniques are similar to inlays. Fixed bridges A bridge is a dental prosthesis that replaces a missing tooth or teeth and is attached permanently to one or more natural teeth (or implants). It is not removable by the patient. Definitions Abutment tooth A tooth which supports a bridge. Retainer Part of a bridge which is cemented or bonded to an abutment tooth. Pontic Each replacement tooth in a bridge. Unit Each part of a bridge, i.e. abutment or pontic, is referred to as a unit. Thus two abutments and one pontic constitutes a three-unit bridge. Pier Non-terminal intermediate abutment. Span The part of a bridge that covers the edentulous area Joint/Connector The junction between any two units of a bridge O p erati v e dentistry Retainer Movable joint Pier abutment • 551 Abutment tooth Fixed joint Pontic Five-unit bridge Lateral view Figure 19.9 Bridge components. The components of a bridge are illustrated in Figure 19.9. Indications for bridgework. Aesthetic tooth replacement; occlusal stability – prevention of drifting, tilting, overeruption; function – usually in posterior regions; periodontal – a bridge is tooth supported (and covers less tissue) so is often considered more favourable to the periodontium than a removable prosthesis; small bounded saddles – ideal for fixed bridgework. Disadvantages of bridgework. Tooth tissue destruction for con­ ventional bridges; expensive; difficult to repair; more complex oral hygiene skills needed by patient. General considerations in bridgework Patients. Patients often consider a fixed prosthesis more favourable than a removable prosthesis. However, bridges are costly in terms of tooth tissue, time and cost. Patients need to learn and master more complicated oral hygiene skills. Saddle. Small saddles are more favourable than large saddles; however, marked bone resorption can be a problem as bridges cannot replace large amounts of alveolar tissue. A bridge in this situation may cause aesthetic or speech problem issues. Abutment teeth. Teeth of small occlusogingival height unfavour­ able – as a