This document summarizes several modern non-invasive methods for caries diagnosis, including methods based on changes in optical properties between healthy and carious tissue. It describes techniques such as fluorescence, optical coherence tomography, polarized Raman spectroscopy, fiber optic transillumination, and the Midwest Caries I.D. system. The techniques use light, scattering, absorption, and fluorescence to detect differences between sound and carious enamel or dentin in a non-invasive manner to allow for early detection and monitoring of dental caries.
This document discusses different types of finish lines used in fixed prosthodontic restorations. It defines finish lines and describes their principles and configurations for both extracoronal and intracoronal restorations. For extracoronal restorations, finish line types for full veneer crowns, partial veneer crowns, and laminate veneers are explained. For intracoronal restorations, finish line designs and bevels for direct restorations using amalgam, composites, and direct gold are outlined. Guidelines for finish line placement and exposure techniques are also provided.
The presentation depicts in a very simplified manner the steps of cavity preparation and restoration of class 3 and class 5 composite restoration. It is well supported with illustrations that further provide a better understanding of the topic.
This document provides an overview of gutta percha, including its discovery, historical uses, sources, evolution in dentistry, composition, chemistry, phases, properties, and commercial manufacture. Gutta percha is a natural polymer that has been used in dentistry as a root canal filling material since the 19th century due to its biocompatibility and ability to adapt to canal walls and provide a fluid-tight seal at the apex. It exists in alpha and beta crystalline forms that impact its viscosity and handling properties for different obturation techniques.
The document discusses mouth guards, including their purpose, types, and importance in preventing dental and other injuries during contact sports. It notes that mouth-formed mouth guards are most commonly used but custom-made ones provide the best protection. Dental providers should educate patients on proper use and maintenance of mouth guards. The document also discusses dental desensitizing agents that can be used in the dental office and at home.
DIAGNOSTIC SETUP FOR REMOVABLE PARTIAL DENTURE /prosthodontic coursesIndian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
A number of theories have been put forward for impressions. each having its own advantage and disadvantage.
Different spacers guide and aid in in making the desired impression with adequate pressure in the desired region of the arch in maxilla and mandible. different materials are used for spacers depending on the need.
Introduction
History
Bleaching agent
Classification of Bleaching technique.
Vital bleaching technique
Effect of vital bleaching on tooth structure
Effect of vital bleaching on tetracycline stain
Effect of vital bleaching on Fluorosis stain
Effect of vital bleaching on restorative material
Conclusion
References
Wedges are used to separate teeth during restorations and are placed in the gingival embrasures. There are different types of wedges including round, triangular, piggyback, and double wedging. Wedges can be made of wood or plastic. Wooden wedges are cheaper and absorb moisture to ensure retention, while plastic wedges allow light transmission. Triangular wedges are ideal for class II cavities as they provide wedging closer to the gingival margin. Placement of a single round wedge involves breaking off a toothpick, grasping it with pliers, and inserting it gingivally to tightly adapt the matrix band. Additional wedges may be needed for wide proximal boxes or concavities
Liners and bases are placed between dentin (or pulp) and a restoration to provide pulpal protection. Liners are thin layers that provide a barrier against residual reactants and oral fluids penetrating between the restoration and tooth. Bases are thicker (1-2mm) and provide additional thermal protection and support restoration forces. The need for liners depends on the restoration material and cavity location/depth. Newer liners focus on chemical protection through sealing and adhesion rather than pulpal medication. The choice of liner depends on remaining dentin thickness and restoration material.
class Ii cast metal restorations like indirect inlay and onlay for restoration of posterior teeth.Cutting technique for inlay and onlay and impression techniques..
An inlay may cap none, or may cap all but one cusp.
Sturdevant’s 4th ed. page579
Inlays may be used as single-tooth restorations for proximo-occlusal or gingival lesions with minimal to moderate extensions
Shillingburg page 1
An inlay may be defined as a restoration which has been constructed out of mouth from gold, porcelain, or other material & then cemented into the prepared cavity of a tooth.
William McGehee pg410
This document discusses acid etching of dental surfaces. It describes how acid etching was first proposed in 1955 to increase bond strength between composite resin and enamel. Acid etching removes enamel and creates an irregular porous surface that allows resin to penetrate through micromechanical interlocking, improving bond strength. Factors like acid type/concentration, etching duration, and fluoride levels can affect bonding. While acid etching is effective, some alternatives under investigation include crystal growth solutions, air abrasion, and lasers, but they have not achieved bond strengths as high as acid etching.
This document provides an overview of radiographic techniques and interpretations in endodontic diagnosis. It discusses the history of dental radiography and various radiographic techniques including intraoral periapical, bitewing, occlusal, tomography, computed tomography, cone beam computed tomography, scanography, stereography, magnetic resonance imaging, digital subtraction radiography and direct digital radiography. It also covers interpreting dental caries, trauma, pulpal and periapical lesions, restorations and dental materials, and root canal anatomy on radiographs. The document emphasizes that cone beam computed tomography is more accurate than conventional radiography for detecting vertical root fractures in teeth with metallic posts.
This document discusses dental composites, including their:
- History dating back to the 1940s and developments since then
- Composition of a matrix, fillers, and coupling agent
- Classification based on filler size, curing method, area of use, and generations
- Properties including strength, smoothness, and polymerization shrinkage
- Advantages such as esthetics and bond strength, as well as disadvantages like polymerization shrinkage.
This document discusses concepts of occlusion in fixed partial dentures. It defines key terms like centric relation and occlusion. It describes the requirements for optimal occlusion, including simultaneous bilateral contact of posterior teeth in centric occlusion and forces directed along the long axis of teeth. It also discusses mandibular movements, border movements, and functional movements. The document outlines the diagnosis of occlusion through intraoral exam, radiographs, and mounted casts. It describes planning occlusion and achieving an optimal occlusion.
A non-cavitated caries lesion ( an early lesion, an incipient lesion, a white spot lesion or a surface softened defect) is a demineralized lesion without evidence of cavitation.
The document discusses the history and properties of direct filling gold (DFG), which has been used as a restorative material in dentistry since the 15th century. It describes different forms of gold used for restorations, including gold foil, electrolytic precipitate gold, and powdered gold. The document also covers the properties that make gold suitable for dental restorations, such as its malleability, ductility, biocompatibility, and cohesiveness.
Tissue conditioners are temporary denture liners composed of polyethylmethacrylate and aromatic esters that form a gel when mixed. They have several uses: as adjuncts for tissue healing by protecting irritated tissues before denture fabrication; as temporary obturators over existing dentures; to stabilize denture bases and surgical splints; and to diagnose the effects of resilient denture liners. Tissue conditioners are applied by reducing the denture base, mixing the three components, and molding the material to the denture tissues. They require gentle cleaning to prevent tearing but only provide temporary relief due to loss of plasticizers over 4-8 weeks.
Caries diagnosis involves assessing factors like patient history, clinical examination, radiographs, and risk factors to determine if a lesion is active, progressing slowly, or arrested. Diagnosis tools include visual/tactile examination, fiber optic transillumination, and electronic caries monitors. High risk factors include poor oral hygiene, low fluoride exposure, and xerostomia while low risk factors include good oral hygiene, fluoridated water, and fluoride supplements.
The document describes a case of anaphylactic shock that occurred during general anesthesia in an 80-year-old female patient undergoing surgery for a wrist fracture. Approximately 15 minutes after induction, the patient experienced tachycardia, low end-tidal carbon dioxide, high airway pressure, weak pulse, decreased breathing sounds, and ST depression on EKG. Cardiopulmonary resuscitation was performed and epinephrine was administered. The patient later displayed erythematous changes and was transferred to the ICU. Laboratory tests showed elevated cardiac enzymes indicating a possible cardiac event during the anaphylactic reaction.
This document provides an overview of shock, including its definition, types, etiology, pathogenesis, stages, and pathophysiological changes. It discusses the classification of shock into types such as hypovolemic, septic, traumatic, neurogenic, and distributive shock. For septic shock specifically, it covers the etiology as severe infection, pathophysiology involving the immune response and release of toxins, and key features including hypotension, tissue hypoperfusion, and high mortality rates. Treatment focuses on fluid resuscitation and source control for hypovolemic and septic shock.
This document discusses several techniques for removing caries from teeth in a less invasive manner than traditional drilling. It describes techniques such as ozone therapy, air abrasion, chemomechanical caries removal, use of smart burs that only remove decayed tooth structure, stepwise excavation, and use of lasers or ultrasonics. For each technique, it provides brief details about how the technique works and its advantages, such as being less painful for patients and removing only decayed tooth material while leaving healthy tooth structure intact. The goal of these alternative caries removal techniques is to better preserve the pulp and reduce risks of negative pulpal outcomes.
This document defines and describes shock, including its basic causes, contributing factors, dangers, signs and symptoms, and types. Shock is a depressed condition where not enough blood circulates due to injury or illness. The basic causes are pump failure from heart damage, hypovolemia from blood or fluid loss, and relative hypovolemia where blood vessels dilate too much. Signs include pale or cold skin, irregular breathing and pulse. First aid aims to improve circulation and oxygen supply while maintaining normal body temperature.
Charles Robert Richet and Paul Portier coined the term "anaphylaxis" in 1902 to describe a dog's fatal reaction to repeated injections of jellyfish toxin. Anaphylaxis is a type I hypersensitivity reaction mediated by IgE antibodies that causes symptoms such as low blood pressure, rashes, and breathing difficulties upon reexposure to an antigen. Perioperative anaphylaxis is difficult to diagnose due to masking by anesthesia drugs and procedures. Treatment involves epinephrine, oxygen, fluids, steroids, and bronchodilators. Muscle relaxants are a common cause, while antibiotics, latex, and protamine also carry risks. Thorough history screening and allergy testing can help prevent severe anaph
The document discusses traumatic brain injury (TBI) and its relationship to domestic violence. It notes that every 23 seconds someone in the US sustains a TBI, and over 90% of domestic violence injuries occur to the head, face or neck. Living with TBI can make it difficult for abused women to safely leave their partners or care for themselves and their families. The document outlines common cognitive, physical and psychosocial effects of TBI and resources for treatment and support.
New Technologies in Caries Diagnosis: The Canary System in Pediatric PracticeDr Marielle Pariseau
Shifting from a surgical approach in Dentistry to one of risk management and meaningful prevention because we know that when a lesion is left to extend until a filling is needed, the clinical opportunity for effective prevention is lost.
Endodontics is the specialty of dentistry that manages the dental pulp and surrounding tissues. It involves diagnosing and treating issues like pulpal nerve damage, which can cause pain or sensitivity. Diagnostic tests are used to examine the tooth and determine the specific condition, such as pulpitis or a periradicular abscess. Common endodontic procedures include pulpotomy, pulpectomy, and root canal therapy which aim to preserve or remove the pulp and disinfect and fill the root canals. Surgical endodontic procedures like apicoectomy and retrograde restoration are needed when non-surgical root canal treatment fails or to address anatomical issues.
Intracanal medicaments are used to disinfect the root canal system, reduce microorganisms, and render canal contents inert. Common intracanal medicaments include phenolics, eugenol, parachlorophenol, formocresol, glutaraldehyde, calcium hydroxide, and antibiotics. The ideal intracanal medicament is an effective germicide and fungicide that remains stable, has prolonged antimicrobial effects, and does not interfere with tissue repair or stain tooth structure. However, no single agent fulfills all these criteria.
Traumatic Brain Injury occurs when sudden trauma damages the brain through bleeding, bruising or tearing of nerves. Common causes include car, motorcycle or bicycle accidents, falls, violence, explosions or abuse. Symptoms vary but may include unconsciousness, headaches, vomiting, dizziness, seizures, weakness or speech/memory problems. Doctors assess severity using scales like the Glascow Coma Scale and perform tests like CT/MRI scans and intracranial pressure monitors. Treatment focuses on reducing swelling through medications, therapy, and sometimes surgery while rehabilitation addresses physical, occupational and speech therapy which may continue for months or years. Prevention emphasizes seatbelt/helmet use and avoiding falls or substance abuse. TBI affects patients and
Procedural accidents in root canal treatment last oneammar905
- Immediately stop procedure
- Check throat and mouth of patient
- Monitor vital signs
- Call emergency services if needed
Dentist:
- Reassure patient
- Take appropriate radiographs
- Monitor patient and seek medical advice as needed
Prognosis depends on:
- Location and size of object
- Time elapsed before removal
- Patient's general health
A root canal is a treatment to remove the infected or inflamed pulp from the inside of a tooth. The pulp contains blood vessels, nerves, and connective tissue. Reasons for needing a root canal include deep tooth decay, cracks, injuries, or electively to better retain a crown. Left untreated, infection from the pulp can spread and cause bone loss around the tooth. During a root canal, an endodontist carefully cleans, shapes, and seals the inside of the tooth to prevent further infection.
Strategies for Managing White Spot Lesions in Orthodontic Patients and A Sugg...safabasiouny1
“white opacity,” occur as a result of subsurface enamel demineralization that is located on smooth surfaces of teeth. Or “subsurface enamel porosity from carious demineralization” that presents itself as “a milky white opacity when located on smooth surfaces
Etiology:
1. prolonged “undisturbed” plaque accumulation on the affected teeth surface, commonly due to inadequate oral hygiene. Under these conditions, acids diffuse into the enamel and the demineralization continues in the subsurface enamel, then the intact enamel surface collapses and becomes cavitated.
2. The presence of fixed orthodontic appliances causes an increasing number of plaque retention sites as a result of the presence of brackets, bands, wires, and other applications, which makes the cleaning of teeth more difficult. furthermore, excess bonding, long etching time (>15 s), decayed/treated molars, and the duration of treatment are considered other risk factors
3. The other important factors that impact this process are the patient’s modifying factors, including medical history, dental history, medication history, diet, levels of calcium, phosphate, and bicarbonate in saliva, fluoride levels, and genetic susceptibility.
Incidence:
• Orthodontic treatment has been reported as the most frequent factor for this situation, and equal susceptibility has been reported whether teeth are banded or bonded.
• The prevalence of WSLs varies widely in the literature. It ranges from 23 to 95%. The reported prevalence of WSLs is quite variable, depending on the sample size, method of detection, the use of a fluoride regimen during treatment, inclusion of pre-existing developmental enamel defects, and selected patients' groups.
• WSLs developed more frequently in the maxillary arch than they did in the mandibular.
• The researchers identified other risk factors during the treatment such as treatment time exceeded 36 months, patients with poor oral hygiene, and patients whose oral hygiene declined during treatment and pre-existing WSLs.
• They observed that the lesions are often symmetrical.
• WSLs are often seen under loose bands, around the periphery of the bracket base and in areas that are difficult to be detected by the patient and not easily accessed by the toothbrush
• More frequently on the maxillary laterals, maxillary canines, and mandibular molars. In other studies, different results were obtained. According to these studies, the most inclined teeth to demineralization are the first permanent molars, the maxillary incisors, the mandibular lateral incisors, and canines.
Dental caries is defined as a localized pathological process caused by acids produced by bacteria in dental plaque that leads to demineralization of tooth hard tissues. Diagnosis of caries involves detecting lesions, assessing activity, and determining risk factors to identify lesions requiring treatment and persons at high risk. A variety of tools can be used for caries diagnosis including visual inspection, fiber-optic transillumination, and diagnostic technologies assessing properties like fluorescence. The International Caries Detection and Assessment System (ICDAS) provides a standardized visual method for caries detection and assessment and has demonstrated validity though performance varies depending on tooth type and surface.
This document summarizes a presentation on operative dentistry topics including diagnosis of dental caries, caries risk assessment, and approaches to caries management. It discusses various methods for diagnosing caries such as visual-tactile examination, radiography, electrical conductance measurements, and lasers. It also outlines factors considered in caries risk assessment and describes management approaches like air abrasion, ozone treatment, chemo-mechanical removal, and lasers that remove caries while preserving tooth structure compared to traditional drills.
white spot lesion - prevention and managementAshok Kumar
This document discusses white spot lesions (WSLs), which appear as white opacities on tooth enamel caused by demineralization. It covers the classification, prevalence, risk factors, detection methods, and prevention/treatment of WSLs. The key prevention strategies discussed are the use of topical fluorides like toothpaste, varnishes, and fluoride-releasing materials. Dietary modifications and antimicrobials are also reviewed as secondary prevention methods. Emerging treatments explored include casein phosphopeptide, lasers, and nanotechnology to enhance remineralization of enamel.
This document discusses white enamel lesions. It defines white spot lesions as subsurface enamel demineralization that appears clinically as a milky white opacity. It classifies white lesions as either carious or non-carious. Carious lesions are white spot lesions caused by prolonged plaque accumulation, while non-carious lesions can be due to trauma, dental fluorosis, or developmental defects. The document discusses methods for diagnosing and evaluating white lesions, as well as various treatment options including prevention, remineralization, resin infiltration, and restoration.
The document discusses several modern dental technologies including:
1. Diagnodent and dental microscopes which can better detect caries and preserve tooth structure.
2. Composite resins and air abrasion which provide improved materials and techniques for fillings and stain removal.
3. CT scans, bone grafting, and CBCT which enhance imaging and implantation procedures.
4. Digital x-rays, intraoral cameras, and intraoral scanners which provide digital alternatives to traditional imaging and impressions.
This document discusses various chairside investigations that can be performed to examine dental caries and pulp disease. It describes tests such as caries dyes, transillumination, electrical conductance measurement, laser fluorescence, and endoscopy that can detect dental caries. It also discusses pulp vitality tests involving heat, cold, or electricity to determine pulp status. Additional tests mentioned include lactobacillus colony count, Snyder test, and salivary buffer capacity tests to assess caries activity.
1st.Chairside Investigations in dental care.pptxswarnimakhichi
This document provides an overview of various chairside investigations used in dentistry. It discusses 10 different types of chairside tests including pulp vitality tests, caries detection tests, and tests for vascular lesions, epithelial lesions, xerostomia, periodontal disease, and more. Specific tests described in detail include thermal pulp testing using heat or cold, electric pulp testing, laser doppler flowmetry, pulse oximetry, diascopy, caries dyes, fiber optic transillumination, and using electrical resistance to detect caries. The document aims to classify and explain the procedures and applications of important clinical investigations that can be performed at the chairside.
Visual inspection alone has low sensitivity in detecting early caries lesions. This study assessed the effect of magnification and air drying on detecting occlusal caries in 44 extracted teeth using naked eye, magnifying loupes, and stereomicroscope, both before and after air drying. The results showed that visual examination before and after air drying had the highest specificity but lowest sensitivity, while magnifying loupes after air drying had the highest sensitivity but lowest specificity compared to other diagnostic techniques. In conclusion, magnification and air drying can improve the detection of early occlusal caries compared to visual examination alone.
Radiographic Aids in the Diagnosis of Periodontal Diseases.pptxRoshnaTalibMustafa
This document discusses the use of radiographs in diagnosing periodontal diseases. It begins by explaining that radiographs are valuable for diagnosis, assessing severity, prognosis, and treatment outcomes, but are an adjunct to clinical exams. It then discusses specific radiographic techniques like periapical and bitewing projections. Advanced imaging modalities like cone-beam CT are described as offering advantages over conventional radiography. The remainder describes the radiographic appearance of various periodontal conditions like chronic periodontitis, furcation involvement, abscesses, and trauma from occlusion.
Advance method in detection of dental caries copyNUHA ELKADIKI
This document discusses new methods for detecting dental caries. It describes several technologies for caries detection, including DIAGNOdent which uses fluorescence, digital imaging fiber-optic transillumination, quantitative light-induced fluorescence, and electrical conductance. Radiography is also discussed as a valuable tool for detecting interproximal and recurrent caries. The document emphasizes that no single method can detect caries with 100% accuracy and advocates a cautious approach to restoration based on modern caries management principles.
A absolutely minimalist way to describe each and every diagnostic aid in the beautiful stream of endodontics.
one has to understand the topic by going through the bible, "Grossman 13th Edition" along with the slides I've created.
Hope this helps.
by Dr. Ishaan Adhaulia
This document discusses early diagnosis of dental caries. It defines dental caries and outlines various diagnostic methods including visual and tactile inspection, caries detection dyes, radiography, fiber optic transillumination, and digital methods. Radiography provides additional information compared to visual examination alone but has limitations in detecting enamel lesions. Digital radiography and subtraction techniques allow comparisons over time. Overall, early and accurate diagnosis is important for determining treatment and prognosis.
This document discusses white spot lesions that can form during orthodontic treatment with fixed appliances. It defines white spot lesions as subsurface enamel porosity from demineralization that appears as milky white opacities on smooth surfaces. Studies have found prevalence rates of white spot lesions ranging from 49.6-97% in orthodontic patients. Risk factors include fixed appliances increasing plaque retention. Diagnosis methods include clinical examination, photography, and optical methods like quantitative light-induced fluorescence. Prevention emphasizes good oral hygiene and supplemental fluoride from sources like fluoridated toothpaste, mouthwashes, varnishes and fluoride-releasing orthodontic adhesives and sealants.
Absorption spectrum analysis of dentine sialophosphoprotein (dspp) in orthodo...Conference Papers
- The document analyzes the absorption spectrum of dentine sialophosphoprotein (DSPP) in gingival crevicular fluid (GCF) samples from orthodontic patients to develop a model for detecting orthodontic-induced inflammatory root resorption (OIIRR).
- GCF samples were collected from orthodontic patients at different treatment periods (3, 6, 12 months) and from non-orthodontic patients. Absorption spectroscopy found DSPP absorbance spectra increased with longer treatment duration, indicating more DSPP released due to more OIIRR.
- A qualitative model using SIMCA analysis accurately classified GCF samples into orthodontic and non-orthodont
Absorption spectrum analysis of dentine sialophosphoprotein (dspp) in orthodo...Conference Papers
- The document analyzes the absorption spectrum of dentine sialophosphoprotein (DSPP) in gingival crevicular fluid (GCF) samples from orthodontic patients to develop a model for detecting orthodontic-induced inflammatory root resorption (OIIRR).
- GCF samples were collected from orthodontic patients at different treatment periods (3, 6, 12 months) and from non-orthodontic patients. Absorption spectroscopy found DSPP absorbance spectra increased with longer treatment duration, indicating more DSPP released due to more OIIRR.
- A qualitative model using SIMCA analysis accurately classified GCF samples into orthodontic and non-orthodont
Keys of Identification for Indian Wood: A Seminar ReportGurjant Singh
Identifying Indian wood involves recognizing key characteristics such as grain patterns, color, texture, hardness, and specific anatomical features. These identification keys include observing the wood's pores, growth rings, and resin canals, as well as its scent and weight. Understanding these features is essential for accurate wood identification, which is crucial for various applications in carpentry, furniture making, and conservation.
Additionally, the application of Convolutional Neural Networks (CNN) in wood identification has revolutionized this field. CNNs can analyze images of wood samples to identify species with high accuracy by learning and recognizing intricate patterns and features. This technological advancement not only enhances the precision of wood identification but also accelerates the process, making it more efficient for industry professionals and researchers alike.
The extremotolerant desert moss Syntrichia caninervis is a promising pioneer ...Sérgio Sacani
Many plans to establish human settlements on other planets focus on
adapting crops to growth in controlled environments. However, these settlements will also require pioneer plants that can grow in the soils and
harsh conditions found in extraterrestrial environments, such as those
on Mars. Here, we report the extraordinary environmental resilience of Syntrichia caninervis, a desert moss that thrives in various extreme environments. S. caninervis has remarkable desiccation tolerance; even after
losing >98% of its cellular water content, it can recover photosynthetic
and physiological activities within seconds after rehydration. Intact plants
can tolerate ultra-low temperatures and regenerate even after being stored
in a freezer at 80C for 5 years or in liquid nitrogen for 1 month.
S. caninervis also has super-resistance to gamma irradiation and can survive and maintain vitality in simulated Mars conditions; i.e., when simultaneously exposed to an anoxic atmosphere, extreme desiccation, low temperatures, and intense UV radiation. Our study shows that S. caninervis is
among the most stress tolerant organisms. This work provides fundamental insights into the multi-stress tolerance of the desert moss
S. caninervis, a promising candidate pioneer plant for colonizing extraterrestrial environments, laying the foundation for building biologically sustainable human habitats beyond Earth.
This an presentation about electrostatic force. This topic is from class 8 Force and Pressure lesson from ncert . I think this might be helpful for you. In this presentation there are 4 content they are Introduction, types, examples and demonstration. The demonstration should be done by yourself
History & overview of Bioprocess Technology.pptxberciyalgolda1
Bioprocess technology is a field that merges biology, chemistry, and engineering to develop processes that harness living cells or their components (like enzymes) for the production of pharmaceuticals, chemicals, food, and biofuels. This multidisciplinary field has evolved significantly over the past few decades, playing a crucial role in various industries.
Towards Wearable Continuous Point-of-Care Monitoring for Deep Vein Thrombosis...ThrombUS+ Project
Kaldoudi E, Marozas M, Jurkonis R, Pousset N, Legros M, Kircher M, Novikov D, Sakalauskas A, Moustakidis P, Ayinde B, Moltani LA, Balling S, Vehkaoja A, Oksala N, Macas A, Balciuniene N, Bigaki M, Potoupnis M, Papadopoulou S-L, Grandone E, Gautier M, Bouda S, Schloetelburg C, Prinz T, Dionisio P, Anagnostopoulos S, Drougka I, Folkvord F, Drosatos G, Didaskalou S and the ThrombUS+ Consortium, Towards Wearable Continuous Point-of-Care Monitoring for Deep Vein Thrombosis of the Lower Limb. In: Jarm, T., Šmerc, R., Mahnič-Kalamiza, S. (eds) 9th European Medical and Biological Engineering Conference. EMBEC 2024. IFMBE Proceedings, vol 113. Springer, Cham. https://doi.org/10.1007/978-3-031-61628-0_36
Presented by Dr. Stelios Didaskalou, ThrombUS+ Project Manager
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
just download it to see!
TOPIC: INTRODUCTION TO FORENSIC SCIENCE.pptximansiipandeyy
This presentation, "Introduction to Forensic Science," offers a basic understanding of forensic science, including its history, why it's needed, and its main goals. It covers how forensic science helps solve crimes and its importance in the justice system. By the end, you'll have a clear idea of what forensic science is and why it's essential.
Prototype Implementation of Non-Volatile Memory Support for RISC-V Keystone E...LenaYu2
Handling confidential information has become an increasingly important concern among many areas of society. However, current computing environments have been still vulnerable to various threats, and we should think they are untrusted.
Trusted Execution Environments (TEEs) have attracted attention because they can execute a program in a trusted environment constructed on an untrusted platform.
Particularly, the RISC-V Keystone is one of the interesting TEEs since it is a flexibly customizable and fully open-source platform. On the other hand, as same as other TEEs, it must also delegate I/O processing, such as file accesses, to a host OS, resulting in the expensive overhead. For this problem, we thought utilizing byte-addressable non-volatile memory (NVM) modules is a useful solution to handle persistent data objects for TEEs.
In this paper, we introduce a prototype implementation of NVM support for the Keystone. Additionally, we evaluate it on the Freedom U500 built on a VC707 FPGA dev kit.
https://ken.ieice.org/ken/paper/20210720TC4K/
Search for Dark Matter Ionization on the Night Side of Jupiter with CassiniSérgio Sacani
We present a new search for dark matter (DM) using planetary atmospheres. We point out that
annihilating DM in planets can produce ionizing radiation, which can lead to excess production of
ionospheric Hþ
3 . We apply this search strategy to the night side of Jupiter near the equator. The night side
has zero solar irradiation, and low latitudes are sufficiently far from ionizing auroras, leading to a lowbackground search. We use Cassini data on ionospheric Hþ
3 emission collected three hours either side of
Jovian midnight, during its flyby in 2000, and set novel constraints on the DM-nucleon scattering cross
section down to about 10−38 cm2. We also highlight that DM atmospheric ionization may be detected in
Jovian exoplanets using future high-precision measurements of planetary spectra.
Science-9-Lesson-1 ang lesson 2-NLC-pptx.pptxJoanaBanasen1
just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it! just check it!
Types of Garden (Mughal and Buddhist style)saloniswain225
Garden is the place where, flower blooming on a plant ,aesthetic things are present like Topiary, Hedges, Arches and many more. Whereas, Botanical garden is an educational institution for scientific research as well as gathering information about different culture. Such as, Hindu, Mughal , Buddhist style.
Cause and solution of Water hyacinth (Terror of Bengal)saloniswain225
Water hyacinth is a buoyant plant that has a clump of leaves with squishy stalks arising from the lower feathery roots and it is an invasive species came from South America
1. 168
A REVIEW OF MODERN NON-INVASIVE METHODS FOR
CARIES DIAGNOSIS
N.K.Prabhakar*
, Kiran kumar .N*
, M.Kala*
ABSTRACT
This paper details the current techniques for the detection of caries using non-invasive techniques, namely Caries
Detection Methods Based on Changes in Optical Properties between Healthy and Carious Tissue. To create opportunity
for a preventative approach to the management of caries, it is important to keep abreast of developments in diagnostic
systems. This article is intended to assist practitioners in developing their knowledge and understanding of the
modern management of caries by providing an update on emerging diagnostic systems, techniques, description as to
how each of the modalities function, consideration is given to recent advances and changes in the relevant technologies,
and review of the same.
AOSR 2011;1(3):168-177.
KEYWORDS: Dental caries, Fluorescence, Transillumination, Optical coherence.
* Department of Conservative Dentistry and Endodontic, Govt. Dental College & Research Institute, Bangalore-560002,
INDIA.
INTRODUCTION :
Dental caries continues to be a common chronic disease
among various population groups. Patient care can be
improved with detection at the earliest stage. However,
current techniques like visual, tactile and radiographs
do not have sufficient sensitivity and specificity. The
visual method cannot help in detecting the caries in
its very early stage and discoloration of pits and fissure
can be misinterpreted as caries. The tactile method holds
the potential to transmit cariogenic bacteria from
one site to another and also may produce irreversible
traumatic defects in potentially remineralizable defects.
The commonly used methods of radiographs is a two
dimensional image of a three dimensional object.
Because of this sometimes interpretation becomes
difficult. Many of these limitations have been overcome
by subtraction radiography but still correct projection
geometry is mandatory. The difficulty of reliably
diagnosing early lesions of caries is well documented,
let alone more extensive lesions.1,2
The profession has
for too long relied on good vision and clinical acumen
for the clinical and radiographic diagnosis of caries. The
use of new systems and techniques in the diagnosis of
caries, if properly applied, can improve reliability, let
alone aid in the detection of early demineralisation,
which may not be apparent clinically. In addition, new
diagnostic modalities allow early lesions of caries to be
quantified, thereby creating the opportunity to monitor
caries progression, or resolution by remineralisation. Such
developments reduce the reliance on subjective visual
examination, although this is still a key skill, supplemented
from time to time by radiographs, and create opportunities
for a preventative rather than the now outdated “drill
and fill” approach to the management of caries.3,4
This
paper reviews optical caries detection methods and these
systems for the diagnosis of caries.
Optical caries detection methods:
Optical caries detection methods are based on observation
of the interaction of energy which is applied to the tooth,
or the observation of energy which is emitted from
the tooth.5
Such energy is in the form of a wave in the
electromagnetic spectrum. The caries detection methods
described in this paper use light in the visible and
near-infrared range (NIR). In its simplest form, caries
can be described as a process resulting in structural
changes to the dental hard tissue. The diffusion of
calcium, phosphate, and carbonate out of the tooth, the
demineralisation process, will result in loss of mineral
content. The resultant area of demineralised tooth
substance is filled mainly by bacteria and water. The
porosity of this area is greater than that of the surrounding
structure. Increased scattering of incident light due to
this structural change appears to the human eye as a so-
called white spot. Hence, the caries process leads to
distinct optical changes that can be measured and
quantified with advanced detection methods based on
light that shines on and interacts with the tooth.
Scattering: Scattering is the process in which the direction
of a photon is changed without loss of energy. The incident
Archives of Oral Sciences & Research
2. 169
light is forced to deviate from a straight path when it
interacts with small particles or objects in the medium
through which the light passes. In physical terms scattering
is regarded as a material property. A glass of milk is seen
as white because incident light on the milk is scattered
in all directions, leaving the milk without absorption.6
Snow appears white because light incident in the snow is
scattered in all directions by the small ice crystals. Light
of all visible wavelengths exits snow without suffering
absorption. Scattering is highly wavelength sensitive,
shorter wavelengths scatter much more than longer
ones.5
Therefore, caries detection methods employing
wavelengths in the visible range of the electromagnetic
spectra (400 nm to 700 nm) are highly limited by scattering.
An early enamel lesion looks whiter than the surrounding
healthy enamel because of strong scattering of light within
the lesion.6
Methods measuring lesion severity are based
on differences in scattering between sound and carious
enamel.
Absorption with Fluorescence: Absorption is the
process in which photons are stopped by an object and
the wave energy is taken in by the object. The energy
lost is mostly converted into heat or into another wave
which has less energy and hence longer wavelengths. In
physical terms absorption is also regarded as a material
property. The previous analogy of the glass of milk
appearing white can be extended to a cup of tea; the tea
is seen as transparent because it does not scatter light,
but it looks brown because much of the light is absorbed
by the tea.5
Likewise, mud and pollution in white snow
can be seen as dark spots because certain wavelengths
are absorbed by these polluted spots. Absorption of
light in tissue is strongly dependent on the wavelength.
Water is an example of a strong absorber in the infrared
range. After absorption the energy can be released by
emission of light at a longer wavelength, through the
process of fluorescence. Fluorescence occurs as a result
of the interaction of the wavelength illuminating the
object and the molecule in this object. The energy is
absorbed by the molecule with subsequent electronic
transition to the next state, to a higher level state where
the electrons remain for a short period of time. From
here the electrons may fall back to the ground state and
release the gained energy in terms of longer wavelength
and colour, which is related to the energy given off
and fluorescent light can be emitted. Autofluorescence,
the natural fluorescence of dental hard tissue without
the addition of other luminescent substances has been
known for a long time.7
Demineralisation will result in
loss of autofluorescence which can be quantified using
caries detection methods based on the differences
in fluorescence between sound and carious enamel.8
Optical coherence tomography (OCT): OCT can be
defined as optical inferometric technique to create cross
sectional images of scattering media. There are various
functional techniques developed in OCT. They are 1)
Polarisation sensitive Optical coherence tomography (PS-
OCT) 2) Doppler OCT 3) Wave length dependent OCT
among these PS-OCT is popular
Studies of light propagation in dental tissue using PS-OCT
revealed strong birefingence in enamel and anisotropic
light propagation through dentinal tubules.9
Amaechi et
al10
used the area under the LCI signal as a measure of
the degree of reflectivity of the tissue and showed that
this area is related to the amount of mineral loss,
and increases with increasing demineralization time.
Hence, OCT could possibly be used to quantitatively
monitor the mineral changes in a caries lesion. In the
early investigations, birefringence induced artefacts in
the enamel OCT image.11
These were eliminated by
measuring the polarization state of the returned light.
Birefringence detected by PS-OCT, however, has been
shown to be useful as a contrast agent indicating pre-
carious or carious lesions in both enamel and dentin.9
Baumgartner et al showed that PS-OCT can provide
additional information related to the mineralization status
and/or the scattering properties of the dental materials.12
The studies demonstrated that PS-OCT is well suited for
the imaging of interproximal and occlusal caries, early
root caries, and for imaging decay under composite
fillings. Longitudinal measurements of the reflected light
intensity in the orthogonal polarization state from the
area of simulated caries lesions linearly correlated with
the square root of time of demineralization indicating that
PS-OCT is well suited for monitoring changes in enamel
mineralization over time.13
OCT provides high resolution morphological depth
imaging of incipient caries. With OCT, early lesions
can be readily identified as regions of high light
backscattering with depth into the enamel as compared to
healthy sound enamel. From the OCT images, the lesion
depth can be approximated to provide clinically useful
information to guide treatment decisions. In addition,
there is a derived parameter known as the optical
attenuation coefficient in order to distinguish sound from
carious enamel non-subjectively. OCT is being combined
with Polarized Raman Spectroscopy (PRS) since regions
of high light backscattering not related to caries
development can lead to false-positive results. PRS
provides biochemical specificity along with molecular
structural/orientational information. With PRS, the
Raman depolarization ratio calculated from the main
phosphate vibration at ~959 cm-1
from parallel- and cross-
polarized Raman spectra allows discrimination between
sound and early developing caries. In combination,
OCT and PRS have potential for detecting and monitoring
early lesions with high sensitivity and high specificity.14
Non-Invasive Methods For Caries Diagnosis
3. 170
Polarized Raman Spectroscopy (PRS): OCT imaging
in regions of hypocalcification can sometimes show
increased light back-scattering at the surface, which
could be misinterpreted as signs of early caries. To
help rule out such false-positive readings and increase
the specificity of this method, OCT and PRS have been
coupled to obtain biochemical information for
confirmation of caries. PRS provides details on the
molecular composition (e.g., collagen in dentin vs.
predominantly inorganic apatite in enamel) and molecular
structure of cells and tissues.
Like OCT, PRS measures light scattering. Although
most scattered photons have the same energy and
wavelength as the incoming excitation light, about 1
in 107
photons scatter at energy different from that of
the incoming light. This energy difference is proportional
to the vibrational energy of the scattered molecules
within the sample and is known as the Raman Effect.
As with other emerging optical methods, the properties
of the scattered light within sound or porous carious
regions are being explored to determine their use in
caries detection.15
In fluorescence-based techniques, there are a limited
number of intrinsic fluorophores that can provide
diagnostic information without the addition of
external dyes. In contrast, PRS can provide information
not only about bacterial porphyrins leached into
carious regions, but also about the primary mineral
matrix and, thus, the state of demineralization or
remineralisation of the tooth. This information is
gathered without the need to add extrinsic dyes or
agents. PRS provides information on the composition,
crystallinity and orientation of the mineral matrix,
all of which are affected in caries formation or
remineralization.15
Fibre Optic Transillumination (FOTI and DIFOTI):
FOTI :
The diagnosis of approximal carious lesions has been
primarily through visual clinical examination. However,
in situations where the teeth are normally in anatomical
contact with others, it is a very difficult task for the
dentist to detect caries in posterior teeth by that
exam, resulting in a high proportion of false negative
decisions.16,17
Conventional bitewing radiography remains the most
common diagnostic aid because it has been shown
to enhance the detection of approximal lesions.17-19
However, there are some problems associated with this
technique, for example, if the horizontal angulation is
incorrect, overlapping of approximal surfaces will occur
on the radiograph. Other problem is the incapacity
of method to distinguish noncavitated from cavitated
lesions.
Fibre-optic transillumination (FOTI) has been investigated
as an alternative method for the detection of approximal
carious lesions.20
In this method, a white light from a
cold-light source is passed through a fiber to an intra-
oral fiber-optic light probe that is placed on the buccal
or lingual side of the tooth and the surfaces are
examined through transmitted light, which is viewed
from the occlusal surface. A carious lesion has a
lowered index of light transmission and so appears as
a darkened shadow when transilluminated.20
FOTI is a
simple, non-invasive, and painless procedure that can
be used repeatedly with no risk to the patient. In the
literature, the validity of diagnoses made with FOTI
has usually been assessed by comparison with the
radiographic diagnosis of the same surface, although it
is well known that radiography itself is not an accurate
method.17-20
Little information is available about
the performance of FOTI in the detection of early
approximal carious lesions in vivo using validation
methods other than radiographic examinations.21,22
Fibre optic consists of a halogen lamp and a rheostat
to produce a light of variable intensity. The 150 watt
lamp generates a maximum light intensity of 4000 lX
at the end of 2.0 mm diameter cable. Two attachments
are used; a plane mouth mirror mounted on a steel
cuff and a fibreoptic probe of 0.5 mm diameter so that
it can be placed in embrasure region. It produces a
narrow beam of light for transillumination. The rheostat
is set to give a light of maximum intensity.
For examination the tip of the probe is placed in
the embrasure immediately beneath the contact point of
the proximal surface to be examined either on the buccal
or lingual surface depending on the tooth. The marginal
ridge is viewed from the occlusal surface.
A shadow extending to the dentinoenamel junction
beneath the marginal ridge may be evident if there is a
break in the integrity of the enamel of marginal ridge.
The Midwest Caries I.D.™*
:
DENTSPLY Professional presents the Midwest Caries
I.D.™ Detection Handpiece, a portable, handheld device
designed to aid in the detection of caries in non-restored
occlusal pits and fissures and interproximal areas on
adult posterior teeth. The combination of LED and
fiber optic technologies enables Clinicians to quickly
and easily detect up to 92% of occlusal caries and
80% interproximal caries. The Midwest Caries I.D.™
Detection Handpiece provides clinicians with an
accurate, easy-to-use instrument. One probe detects
N.K.Prabhakar et al.
*
DENTSPLY Professional Division, York, PA.
4. 171
both interproximal and occlusal caries while providing
clinical access and enhanced visibility, and the visual and
audible caries detection signals provide an ideal end-
user interface. The probe must be used in wet environments
The Midwest Caries I.D.™ system comes complete
with the probe, shell, and detection module. It also
includes a custom cassette, ceramic calibration target,
fiber optic cleaning swabs, polishing papers , AAA lithium
batteries, and directions for use.
DIFOTI :
This is a relatively new methodology that was adopted in an
attempt to reduce the perceived shortcomings of FOTI
by combining FOTI and a digital charge-coupled
device (CCD) camera. Digital Imaging Fiber-Optic
TransIllumination (DIFOTI) has been introduced to
improve early detection of carious surfaces. DIFOTI
uses fiber-optic transillumination of safe visible light to
image the tooth. Light delivered by a fiber-optic is
collected on the other side of the tooth by a mirror
system and fed to a digital electronic CCD. Then the
acquired data are sent to a computer for analysis with
dedicated algorithms, which produce digital images that
can be viewed by the clinician and patient in real time or
stored for later use.23
DIFOTI uses visible light and not the ionising radiation
and is approved by US food and drug administration
for caries detection on approximal smooth and occlusal
surface as well as recurrent caries. DIFOTI uses
scattering of light by carious tissue as a method of
distinguishing it from healthy enamel the carious part of
the tooth appears to be dark against the light background
of healthy tooth.
Schneiderman et al.24
found that DIFOTI technique
has superior sensitivity over conventional radiographic
methods for detection of approximal, occlusal, and
smooth surface caries, and specificity was slightly less
in general. It has all the advantages of FOTI and also
it has overcome the disadvantage of FOTI as images in
this technique can be stored for future reference.
Quantitative Light-induced Fluorescence:
Another dental diagnostic tool for detection of early
carious lesions is quantitative light-induced fluorescence
(QLF), which is based on auto-fluorescence of teeth.
When the teeth are illuminated with high intensity
blue light, the resultant auto-fluorescence of enamel
is detected by an intraoral camera which produces
a fluorescent image. The emitted fluorescence has a
direct relationship with the mineral content of the
enamel.25–27
Thus, the intensity of the tooth image
at a demineralised area is darker than the sound area.
The software of QLF systems can process the image
to provide user quantitative parameters such as lesion
area, lesion depth, and lesion volume. These parameters
can detect and differentiate the lesions at very early
stages, and make the QLF system more sensitive to
changes of caries over time. The image can be stored
for longitudinal study and be used as patient motivators
in a preventative practice.28
QLF uses a blue light (488 nm) to illuminate the
tooth, which normally fluorescence a green colour.
Teeth should be dried before its application.29
Hafström-Björkman et al found a sensitivity of 0.72-
0.76 and a specificity of 0.79-0.81 for this technique.30
This can also be used to image plaque and calculus,
and therefore be useful in identifying active caries. This
technique has found many applications in clinical trials,
research, patient education, and preventive clinical
practice it can effectively monitor demineralization and
remineralisation of teeth invitro and a good correlation
has been reported with other techniques measuring
mineral loss, such as transverse microradiography
analysis.31
Also it can be used to measure erosive
potential of a range of mouth washes invitro and
to see early secondary caries beneath the amalgam
restorations.32
However it cannot differentiate between
decay and hypoplasia; has inability to detect or monitor
interproximal lesions and is limited to measurement of
enamel lesions of at most several hundred micrometers
depth.
Laser-induced Fluorescence:
Recently a compact hand held device has been
marketed, DIAGNODENT.†
This device makes use of
laser autofluorescence technology,33
but instead of
using blue light it uses red light, of wavelength
655nm, output <1mW. This red laser light identifies
caries as having an increased fluorescence over sound
tooth, whereas blue light highlights caries as a reduced
fluorescence compared to sound tooth. These differences
are attributable to the characteristics of light of
different wavelength, and the effects of light of
different wavelength in teeth and lesions of caries.
The science behind this phenomenon appears to be
the increased fluorescence exhibited by cariogenic
bacterial metabolites within the lesion, as well as
the changed fluorescent nature of the lesion itself.34
The DIAGNODENT unit (KaVo) comprises a pen like
device with detachable tips of different diameter. The
central core fibre running through the pen grip and tip
is a red laser, with the surrounding fibres being
detectors to measure the returned fluorescent light
from the tooth surface. A reading is provided on a
digital display accompanied by an audible tone. The
higher the digital reading and pitch of the audible
Non-Invasive Methods For Caries Diagnosis
†
KaVo Dental, Germany
5. 172
tone, the greater the potential for caries involvement
of the amelodentinal junction and the underlying dentine.
Each patient must be individually calibrated, by setting
a base level on a healthy tooth. No definite value can be
given as to when caries is present and when prevention
or intervention is indicated, but scores above 25 are to
be considered to suggest a high probability of caries.
Monitoring can therefore be carried out without the
need for exploratory cavity preparation or radiographs.
Indeed, the level of the earliest detected caries may relate
to a lesion that may not be apparent radiographically.35
The device performs best on smooth surfaces and in
occlusal pits and fissures. Limitations of this device
include the need for the tooth surfaces and fissures
being assessed to be clean and dry. To date there is no
evidence to support the use of DIAGNODENT for the
detection of approximal or secondary caries adjacent
to existing restorations, let alone recurrent caries
subjacent to a restoration, whether metallic or tooth-
coloured. The presence of an existing restoration or
fissure sealant may adversely affect the accuracy of the
device.
Experience, over a one-year period with DIAGNODENT,
both clinically and with extracted teeth in the
laboratory lends support to the views of Ross.36
The
device is relatively straightforward to apply and with
a short familiarisation period can be used to quickly
assess teeth with a high degree of accuracy. Ross reports
that he became less reliant on only clinical visual
examination, and of being more confident as to the exact
location and extent of occlusal caries. This allowed
his management of such caries to become more
conservative. The DIAGNODENT provides a quantitative
measurement to supplement the subjective information
from clinical examination, in reaching a decision as to
when intervention is appropriate.
Transillumination with Near-Infrared light:
The caries lesion may also be examined by shining
white light through the tooth. Wavelengths in the
visible range (400–700 nm) are limited by strong light
scattering, making it difficult to image through more
than 1 mm or 2 mm of tooth structure.37
Therefore,
methods employing wavelengths in the visible range
of the electromagnetic spectra (400–700 nm) such as QLF
(λ > 520 nm), LF (λ = 655 nm), and Digital Imaging
Fiber-Optic Transillumination (DIFOTI)38
which
uses high intensity white light, are highly limited
by scattering. Methods that use longer wavelengths,
such as in the NIR spectra (780-1550 nm), can penetrate
the tissue more deeply. This deeper penetration is
crucial for the transillumination (TI) method. Research
has shown that enamel is highly transparent in the
NIR range (750 nm-1500 nm) due to the weak
scattering and absorption in dental hard tissue at
these wavelengths.39-41
Near-Infrared reflectance imaging:
In this technique, the tooth is exposed to light (irradiation)
with a wave length of between 700 and 1500 nm. Light
scattering in sound dental enamel decreases markedly
in the NIR region and studies have shown that enamel
has the highest transparency near 1310 nm.41,42
At this
wavelength, the attenuation coefficient is only 2 to 3
cm−1
, which is a factor of 20 to 30 times lower than in
the visible region. At longer wavelengths, water
absorption increases significantly and reduces the
penetration of the NIR light. Even though the light
scattering for sound enamel is at a minimum in the NIR,
the light scattering coefficient of enamel increases by
2-3 order of magnitudes upon demineralization due to
the formation of pores on a similar size scale to the
wavelength of the light that act as Mie scatterers.41
Therefore, caries lesions can be imaged with optimal
contrast at 1310 nm.43
And detection is done by infrared
sensitive detectors as CCD or film. According to Christian
Zakian et al 44
a sensitivity of > 99% and a specificity of
87.5% for enamel lesions and a sensitivity of 80% and a
specificity > 99% for dentine lesions. The nature of the
techniqueofferssignificantadvantages,includingtheability
to map the lesion distribution rather than obtaining single-
point measurements, it is also non-invasive, noncontact,
and stain insensitive. These results suggest that NIR
spectral imaging is a potential clinical technique for
quantitative caries diagnosis and can determine the
presence of occlusal enamel and dentin lesions.
Infrared fluorescence:
This technique has seldom been reported. In theory,
the tooth is exposed to light (irradiation) with a
wavelength of between 700 and 15,000 nm. Barrier
filters are used to observe any resulting fluorescence.
Studies by Alfano et al. mention exposure of teeth to
wavelengths exceeding 700 nm, but the results were
not presented.45
Unpublished reports commented upon
by Longbottom suggest that the technique is able
to discriminate between sound and carious enamel
and dentin.46
Further work is required to determine if
the fluorescence signal from exposure to infrared
irradiation is greater than that from other wavelengths.
Additionally, any heating effects from absorption
of infrared irradiation may have potentially damaging
effects on the dental pulp, given the increased
penetration and decreased scattering of the longer
wavelength. Specific coherent sources of such irradiation
have been relatively difficult to acquire, and detection
involves the use of infrared-sensitive detectors as CCDs
or film.
N.K.Prabhakar et al.
6. 173
Terahertz Pulse Imaging: This method uses waves
with tetrahertz frequency(=1012
Hz or a wavelength
of approximately 30µm) for an image to be obtained
by tetrahertz irradiation, the object is placed in the
path of the beam. It is possible to record tetrahertz
images using CCD detector. It has no adverse thermal
effects, it is non ionising low signal to noise ratio, but
the cost of equipment is high, and careful interpretation
is required. Dental Applications for this technique
have been limited but promising. Longitudinal sections
through three teeth have demonsrated increased
terahertz absorption by early occlusal caries and an
apparent ability to discriminate dental caries from
idiopathic enamel hypomineralisation. Work in progress
to image intact teeth with early carious lesion.47
Multiphoton Imaging: Infra red light of 850 nm has
been used for multiphoton imaging of teeth. In
conventional fluorescence imaging (QLF), a single blue
photon is used to excite a fluorescent compound in the
tooth. In the multiphoton technique two infrared photons
(with half the energy of blue photon) are absorbed
simultaneously. With this technique, sound tooth
tissue fluoresces strongly, whereas carious tooth tissue
fluoresces to a much lesser extent. In practice, by using
motors with micron accuracy, one can move the plane
of focus through the tissue and record the sectional
images from the tooth to form a 3D image. Caries will
appear as a dark form with in a brightly fluorescing
tooth. To highlight the diseased tissue, the image may
be displayed in its negative form so that caries appear
bright with in dark tooth.
Time-Correlated Single-Photon Counting Fluorescence
Lifetime Imaging:
It has also been demonstrated that fluorescence lifetime
imaging microscopy (FLIM) has the ability to distinguish
the carious region from sound dental tissue.48-50
Optical
bandpass interference filters were then applied to this
broad-bandwidth source to select the 488 nm excitation
wavelength required to perform TCSPC FLIM of dental
structures. The white-light generation source provides a
flexible method of producing variable-bandwidth visible
and ps-pulsed light for TCSPC FLIM. The results from the
dental tissue indicate a potential method of discriminating
diseased tissue from sound, but stained tissue, which could
be of crucial importance in limiting tissue resection during
preparation for clinical restorations.
CONCLUSION :
Current research and new technologies have extended
the dentists’ armamentarium to detect early lesions
of caries. It is suggested that laser fluorescence is the
leading technology there is, At the current state of
development, early caries detection tools such as QLF,
Electronic caries monitor, DIAGNODENT, DIFOTI or
FOTI should be used as an adjunct to clinical decision
making and serve primarily as a support tool for making
preventive treatment plan decisions in conjunction
with caries risk assessment. It is important that all these
tools be used as diagnostic adjuncts to aid in early
caries detection and not as a justification for premature
restorative intervention. However, a need to further
extend knowledge and understanding of other techniques
Diagnostic method Advantages Disadvantages Clinical application
Optical
coherence tomography
(OCT)
1)Canbeusedtoquantitatively
monitor the mineral changes
in a caries lesion.
2) Can determine depth of the
lesion.
Regions of high light
backscattering not related
to caries development
can lead to false-positive
results.
Imaging of interproximal and
occlusal caries, early root caries,
and for imaging decay under
composite fillings.
Polarized Raman
Spectroscopy (PRS)
1) PRS is a noninvasive
spectroscopic method that
provides details on the
biochemistry and molecular
structure of white spot
lesions.
2) There is no need for
external dyes.
However, factors in the
oral environment such as
calculus,hypocalcification,
and stain could lead to
false-positive results.
Used in conjuction with OCT
for better result.
Fibre Optic
Transillumination
1)Non ionising.
2) Gives instant images.
1) Subject to intra and
interobserver variations.
this is overcome by The
Midwest Caries I.D.™
2) Calculus and hypoca
lcifications are major
confounding factors.
For detection of approximal,
occlusal and smooth surface
caries.
Non-Invasive Methods For Caries Diagnosis
7. 174
Quantitative Light-
induced Fluorescence
1) can provide quantitative
parameters such as lesion
area, depth, and volume.
2) The image can be stored
for longitudinal study.
1) It cannot differentiate
between decay and
hypoplasia.
2) It has inability to detect
or monitor interproximal
lesions.
3)Has Limited depth
measurement.
Has applications in clinical
trials, research, patient
education, and preventive
clinical practice. Can effectively
monitor demineralization and
remineralisation of teeth invitro
Also can be used to measure
erosive potential of a range of
mouth washes in vitro. To see
early secondary caries beneath
the amalgam restorations.
Laser-induced
Fluorescence:
1) Easy and quick to use.
2)Safe and no x-ray exposure.
1)Tooth surfaces and
fissures being assessed
should be clean and dry.
2)No evidence present
for the detection of
approximal or secondary
caries adjacent to existing
restorations.
The device performs best on
smooth surfaces and in occlusal
pits and fissures.
Transillumination with
Near-Infrared light:
1)Less amount of back
scattering
2) Can be easily differentiated
from stains, pigmentation,
and hypomineralization
(fluorosis).
More studies over the
damaging effects on the
pulp needed.
A promising imaging technique
for detecting
the presence of caries and
measuring its severity
Near-Infrared reflectance
imaging
1)The ability to map the
lesion distribution rather
than obtaining single-point
measurements,
2)Non-invasive, noncontact,
and stain insensitive.
More studies over the
damaging effects on the
pulp needed.
For quantitative caries diagnosis
and can determine the presence
of occlusal enamel and dentin
lesions.
Infrared fluorescence Non-invasive, noncontact,
and stain insensitive.
More studies over the
damaging effects on the
pulp needed.
For quantitative caries
diagnosis.
Terahertz Pulse Imaging 1)Relative transparency of
human tissue to terahertz
rays.
2) Adverse thermal effects
are thought to be unlikely.
Care is require in image
interpretation since
terahertzwavesarestrongly
absorbed by water.
Dental applications for this
technique are limited but
promising.
Multiphoton Imaging Able to collect information up
to 500 microns in depth.
It can cause harm to tissues
but it is over come by
using ultra short pulses.
Currently the technique has been
performed only on the extracted
teeth.
Time-Correlated Single-
Photon Counting
Fluorescence Lifetime
Imaging
Relatively safe compared
to two photon excitation
method.51
To obtain high-quality data
acquisition, times up to 30
minutes have been used.
It is possible to differentiate
between carious and sound
regions by time-resolved
fluorescence and that, although
the origin of enamel fluorescence
is still uncertain, the lifetime
values seem to be typical of
fluorophores like collagen I.50
N.K.Prabhakar et al.
8. 175
in the field of dentistry is needed. Unfortunately no
one device has all the advantages and can be called as
ideal. But with the available information following
conclusions can be drawn as presented in table
New devices do offer promise in the monitoring of early
incipient lesions of caries, and therefore preventive
dentistry techniques may be more appropriately targeted
and assessed.
REFERENCES :
1. Ricketts D, Kidd E, Weerheijm K, De Soet H. Hidden
caries: What is it? Does it exist? Does it matter? Inter
Dent J. 1997;47:259-265.
2. Hintze H. Screening with conventional and digital bite-
wing radiography compared to clinical examination
alone for caries. Caries Res. 1993;27:499-504.
3. Pitts N B. Diagnostic tools and measurements – Impact
on appropriate care. Community Dent Oral Epidemiol.
1997;25:24-35.
4. Verdonschot EH, Angmar-Mansson B, Ten Bosch JJ, et
al; Developments in caries diagnosis and their
relationship to treatment decisions and quality of care.
Caries Res. 1999;33:32-40.
5. Bader JD, Shugars DA. “The evidence supporting
alternative management strategies for early occlusal
caries and suspected occlusal dentinal caries,” J Evid
Based Dent Pract. 2006;6:91-100.
6. Angmar-Månsson B, ten Bosch JJ. Advances in
methods for diagnosing coronal caries—A review. Adv
Dent Res. 1993;7:70–79.
7. Benedict HC. A note on the fluorescence of teeth in
ultraviolet rays. Science. 1928;67:442.
8. Borisova E, Uzunov T, Avramov L. Laser-induced
autofluorescence study of caries model in vitro,” Lasers
Med Sci. 2006;21:34–41.
9. Wang XJ, Milner TE, de Boer JF, Zhang Y, Pashley DH,
Nelson JS. Characterization of dentin and enamel
by use of optical coherence tomography. Appl Opt.
1999;38:2092–2096
10. Amaechi BT, Podoleanu A, Higham SM, Jackson
DA. Correlation of quantitative light-induced
fluorescence and optical coherence tomography
applied for detection and quantification of early dental
caries. J Biomed Opt. 2003;8:642-647.
11. Colston BW, Everett MJ, DaSilva LB, Otis LL, Stroeve
P, Nathel H. Imaging of hard and soft tissue in the
oral cavity by optical coherence tomography. Appl
Optics. 1998;37:3582–3585.
12. Baumgartner A, Dichtl S, Hitzenberger CK, Sattmann
H,RoblB,MoritzA,FercherAF,SperrW.Polarization-
sensitive optical coherence tomography of dental
structures. Caries Res. 2000;34:59-69.
13. Fried D, Xie J, Shafi S, Featherstone JD, Breunig TM,
Le C. Imaging caries lesions and lesion progression
with polarization sensitive optical coherence
tomography. J Biomed Opt. 2002;7:618-627.
14. Choo-Smith et al. Towards early dental caries detection
with OCT and polarized Raman spectroscopy. Head &
Neck Oncology 2010;2(S1):O43.
15. Choo-Smith LP, Dong CC, Cleghorn B, Hewko M.
Shedding new light on early caries detection. J Can
Dent Assoc. 2008;74:913-918.
16. Ismail AI. Clinical diagnosis of precavitated carious
lesions. Community Dent Oral Epidemiol 1997;25:
13-23.
17. Pitts NB, Rimmer PA. An in vivo comparison of
radiographic and directly assessed clinical caries status
of posterior approximal surfaces in primary and
permanent teeth. Caries Res. 1992;26:146-152.
18. Hopcraft MS, Morgan MV. Comparison of radiographic
and clinical diagnosis of approximal and occlusal
dental caries in a young adult population. Community
Dent Oral Epidemiol. 2005;33:212-218.
19. Yang J, Dutra V. Utility of radiology, laser fluorescence,
and transillumination. Dent Clin North Am.
2005;49:739-752.
20. Friedman J, Marcus MI. Transillumination of the
oral cavity with use of fiber optics. J Am Dent Assoc.
1970;80:801-809.
21. Hintze H, Wenzel A, Danielsen B, Nyvad B. Reliability
of visual examination, fibre-optic transillumination,
and bite-wing radiography, and reproducibility of
direct visual examination following tooth separation for
the identification of cavitated carious lesions in
contacting approximal surfaces. Caries Res.
1998;32:204-209.
22. Deery C, Care R, Chesters R, Huntington E,
Stelmachonoka S, Gudkina Y. Prevalence of dental
caries in Latvian 11- to 15-year-Old children and the
enhanced diagnostic yield of temporary tooth
separation, FOTI and electronic caries measurement.
Caries Res. 2000;34:2-7.
23.Young DA, Featherstone JD. Digital imaging fiber-
optic trans-illumination, F-speed radiographic film
Non-Invasive Methods For Caries Diagnosis
9. 176
and depth of approximal lesions. J Am Dent Assoc.
2005;136:1682-1687.
24.Schneiderman A, Elbaum M, Shultz T, Keem S,
Greenebaum M, Driller J. Assessment of dental caries
with Digital Imaging Fiber-Optic Trans
Illumination (DIFOTI): in vitro study. Caries Res.
1997;31:103-110.
25. Ando M, Hall AF, Eckert GJ, Schemehorn BR, Analoui
M, Stookey GK. Relative ability of laser fluorescence
techniques to quantitate early mineral loss in vitro.
Caries Res. 1997;31:125-131.
26. Lagerweij M, van der Veen M, Ando M, Lukantsova
L, Stookey G. The validity and repeatability of three
light-induced fluorescence systems: An in vitro study.
Caries Res. 1999;33:220-226.
27. Pretty IA, Pender N, Edgar WM, Higham SM. The
in vitro detection of early enamel de- and re-
mineralization adjacent to bonded orthodontic cleats
using quantitative light-induced fluorescence. Eur J
Orthod. 2003;25:217-223.
28. Feng Y, Yin W, Hu D, Zhang YP, Ellwood RP,
Pretty IA. Assessment of autofluorescence to detect
the remineralization capabilities of sodium fluoride,
monofluorophosphate and non-fluoride dentifrices.
A single-blind cluster randomized trial. Caries Res.
2007;41:358-364.
29. Pretty IA, Edgar WM, Higham SM. The effect of
dehydration on quantitative light-induced fluorescence
analysis of early enamel demineralization. J Oral
Rehabil. 2004;31:179-184.
30. Hafström-Björkman U, Sundström F, Ten Bosch
JJ.Fluorescenceindissolvedfractionsofhumanenamel.
Acta Odontol Scand. 1991;49:133-138.
31. Pretty IA, Pender N, Edgar WM, Higham SM. The in
vitro detection of early enamel de- and re-mineralization
adjacent to bonded orthodontic cleats using
quantitative light-induced fluorescence. Eur J Orthod.
2003;25:217-223.
32. González-Cabezas C, Fontana M, Gomes-Moosbauer
D, Stookey GK. Early detection of secondary caries
using quantitative, light-induced fluorescence. Oper
Dent. 2003;28:415-422.
33. Sundström F, Fredriksson K, Montán S, Hafström-
Björkman U, Ström J. Laser-induced fluorescence
from sound and carious tooth substance: spectroscopic
studies. Swed Dent J. 1985;9:71-80.
34. König K, Flemming G, Hibst R. Laser-induced
autofluorescence spectroscopy of dental caries. Cell
Mol Biol (Noisy-le-grand). 1998;44:1293-1300.
35. Lussi A, Imwinkelried S, Pitts N, Longbottom C, Reich
E. Performance and reproducibility of a laser
fluorescence system for detection of occlusal caries in
vitro. Caries Res. 1999;33:261-266.
36. Ross G. Caries diagnosis with the DIAGNOdent laser: a
user's product evaluation. Ont Dent. 1999;76:21-24.
37. Darling CL, Fried D. Real-time near IR (1310 nm)
imaging of CO2 laser ablation of enamel. Opt Express.
2008;16:2685-2693.
38. Schneiderman A, Elbaum M, Shultz T, Keem S,
Greenebaum M, Driller J. Assessment of dental caries
with Digital Imaging Fiber-Optic Transillumination
(DIFOTI): in vitro study. Caries Res. 1997;31:103-110.
39. BühlerC,NgaotheppitakP,FriedD.Imagingofocclusal
dental caries (decay) with near-IR light at 1310-nm.
Opt Express. 2005;13:573-582.
40. Darling CL, Huynh GD, Fried D. Light scattering
properties of natural and artificially demineralized
dental enamel at 1310 nm. J Biomed Opt.
2006;11:34023.
41. Fried D, Glena RE, Featherstone JD, Seka W. Nature
of light scattering in dental enamel and dentin at
visible andnear-infrared wavelengths. Appl Opt.
1995;34:1278-1285.
42. Jones RS, Fried D. Attenuation of 1310-nm and 1550-
nm Laser Light through Sound Dental Enamel, Lasers
in Dentistry VIII. 2002; 4610:187–190.
43. Fried D, Featherstone JD, Darling CL, Jones RS,
Ngaotheppitak P, Bühler CM. Early caries imaging
and monitoring with near-infrared light. Dent Clin
North Am. 2005 ;49:771-793.
44. Zakian C, Pretty I, Ellwood R.Near-infrared
hyperspectral imaging of teeth for dental caries
detection. J Biomed Opt. 2009;14:064047.
45. Alfano RR, Lam W, Zarrabi HJ, Alfano MA, Cordero
J, Tata DB, et al. Human teeth with and without caries
studied by laser scattering, fluorescence and
absorption spectroscopy. IEEE J Quantum Electr
1984;20:1512–1516.
46. Longbottom C (1999). Quantification of red/infrared
laser fluorescence for early caries detection. In: Early
detection of dental caries II. Proceedings of the
4th Annual Indiana Conference. Stookey GK, editor.
Indianapolis: Indiana University School of Dentistry,
pp. 75–82.
N.K.Prabhakar et al.
10. 177
47. Crawley DA, Longbottom C, Cole BE, Ciesla CM,
Arnone D, Wallace VP, Pepper M. Terahertz pulse
imaging: a pilot study of potential applications in
dentistry. Caries Res. 2003;37:352-359.
48. Webb SE, Leveque-Fort S, Elson DS, Siegel J,
Watson T, Lever MJ, et al. Wavelength-resolved
3-dimensional fluores cence lifetime imaging. J.
Fluoresc. 2002;12:279–283.
49. McConnell G, Girkin JM, Ameer-Beg SM,
Barber PR, Vojnovic B, Banerjee T, et al. Time-
correlated single-photon counting fluorescence lifetime
confocal imaging of decayed and sound dental
structures with a white-light supercontinuum source. J.
Microsc. 2007;225:126–136.
50. Ferretti de Oliveira F, Ito AS, Bachmann L. Time-
resolved fluorescence spectroscopy of white-spot caries
in human enamel. Appl Opt. 2010;49:2244-2249.
51. König K.Multiphoton microscopy in life sciences.
J Microsc. 2000;200:83-104.
Correspondence:
Dr.N.K.Prabhakar,
Room no.4, Department of Conservative Dentistry and Endodontics,
Government Dental College and Research Institute,
Bangalore, Karnataka, India.
Email id:prabhakar.naik0000@gmail.com
Non-Invasive Methods For Caries Diagnosis