Dentistry

Breath odor research captured the scientific community′s attention during the last few decades. Evidence-based studies have justified that halitosis causes social restriction and decreased life quality, and that it may be an indicator for periodontal as well as systemic diseases. This has led to the advances in analytical monitors used for the identification and measurement of the malodourous compounds. The present discussion intends to focus on the etiology, pathophysiology, diagnostic criteria, and the various treatment strategies for halitosis.

Knowledge about the external and internal anatomy of the tooth is essential for successful dental practice. Anomalies in the tooth are often encountered which poses difficulties in dental treatments. As like any other tooth, mandibular first molars are also prone for anatomic malformations. One such anatomic variation is the presence of extra root distolingually. This distolingual root is called radix entomolaris (RE). The presence of an additional root can lead to difficulties during endodontic therapy. This article is a report of two cases describing the management of the first mandibular molars with an RE and clinical guidelines for its management.

The aim of this study was to evaluate the remineralizing potential of three different remineralizing agents (GC tooth Mousse, Clinpro tooth crθme and SHY-NM) on demineralized tooth surfaces using micro CT and microhardness. Forty five freshly extracted mandibular premolars were collected and enamel specimens were prepared. The samples were assigned to three groups with fifteen specimens in each group. The specimens were then demineralized using McInne's demineralizing solution in two cycles. After that, remineralization was carried out in two cycles for 30 days using Casein phosphopeptide - Amorphous calcium phosphate (CPP - ACP), 0.21% sodium fluoride - Tricalcium phosphate (f-TCP) and Calcium Sodium Phosphosilicate (CSP) containing tooth pastes for groups I, II, III respectively. The specimens were evaluated for Linear attenuation co-efficient using micro CT (Scanco™) and Vicker's Micro Hardness (Schimadzu™) testing at different time periods. The results were tabulated and statistically analysed. It was observed that all the three remineralizing agents used in the study significantly increased the Linear Attenuation Co-efficient and Vicker's hardness number values of the enamel specimens following 15 days and 30 days application. CPP - ACP showed the better remineralizing potential than the other two agents and there was no statistical significant difference between f-TCP and CSP groups.

To evaluate the bacteria extruded apically during root canal preparation using two hand and rotary instrumentation techniques. Eighty freshly extracted mandibular premolars were mounted in bacteria collection apparatus. Root canals were contaminated with the pure culture of Enterococcus fecalis (ATCC 29212) and dried at 37°C for 24 h. Bacteria extruded were collected, incubated in brain heart infusion agar for 24 h at 36°C and the colony forming units (CFU) were counted. The mean number of colony forming units were calculated by One-way ANOVA and comparison between the groups made by multiple comparison (Dunnet D) test. The step-back technique extruded highest number of bacteria in comparison to other hand and rotary Ni-Ti systems. Under the limitation of this study all hand and rotary instrumentation techniques extruded bacteria. Among all the instrumentation techniques step-back technique extruded more number of bacteria and K-3 system the least. Further in vivo research in this direction could provide more insight into the biologic factors associated and focus on bacterial species that essentially play a major role in post instrumentation flare-ups.

Several disinfection techniques have been recently introduced with the main objective of improving root canal disinfection in the inaccessible areas of the root canal system. This in vitro study was done to evaluate the antimicrobial effect and viability of Enterococcus faecalis biofilms using conventional irrigation, EndoActivator (Dentsply, Tulsa Dental, USA), diode laser irradiation and photon-initiated photoacoustic streaming (PIPS). Root canals of 130 single rooted mandibular premolars, standardized to a uniform length of 20 mm were instrumented until finishing file, F1 (Universal Protaper Rotary System, Dentsply, Tulsa Dental Specialties, USA). After smear layer removal and sterilization, five teeth were randomly selected to assure sterility before bacterial inoculation. The remaining 125 samples were contaminated with E. faecalis suspension, incubated for 21 days and divided into five groups (n = 25). In Group 1; untreated group (positive control), the root canals were not subjected to any disinfection procedure. Sampling was performed within the canals and the colony-forming unit count was evaluated for 20 samples. Five samples were selected to visualize the pattern of colonization at Level 1 (4 mm from the apex) and Level 2 (1 mm from the apex) by confocal laser scanning microscopy. Samples in Groups 2-5 namely conventional needle irrigation, EndoActivator, diode laser and PIPS were subjected to their respective disinfection procedures. Postdisinfection sample evaluation criteria was followed for all groups as same as that for Group 1. Diode laser displayed the highest antibacterial efficacy and least viable bacteria than the other three disinfection techniques. Diode laser group showed better antibacterial efficacy and least viable bacteria when compared to conventional needle irrigation, PIPS and EndoActivator groups in minimally instrumented, experimentally infected root canals.

The aim of this study was to compare the clinical and radiological outcome of mineral trioxide aggregate (MTA) or epoxy resin as a root canal sealer compared with zinc oxide eugenol sealer. 45 single rooted teeth with periapical index Score 2 or more were allotted to three groups with 15 teeth in each group. Root canal treatment was performed in two visits and obturated with Gutta-percha as obturating material and zinc oxide eugenol as sealer in Group 1, epoxy resin as sealer in Group 2 and MTA mixed with propylene glycol as sealer in Group 3. Visual analog scale, periapical index and VixWin digital Pro image analysis software were used for evaluation. The quantitative data was analyzed by t-test and analysis of variance. Ordinal data was analyzed by Wilcoxon's signed rank test, Mann-Whitney and Kruskall-Wallis test. Results suggested that there exists no statistically significant difference in clinical or radiological outcome of root canal therapy with three different types of ...

Background: Resin composites as direct posterior restorative material was associated with the polymerization contraction and microleakage. Different methods have been introduced to overcome these drawbacks by increasing the degree of monomer conversion and to minimize the polymerization shrinkage. Composite preheating is an innovative method to improve the handling and physical properties. So this study was done to evaluate the effect of prepolymerization warming of different composites on the marginal adaptation.  Materials and Methods: This in vitro study was conducted on 80 extracted human maxillary premolars. Class II cavities on the proximal surface were prepared with the dimensions of 4 mm buccolingual width, 2 mm axial depth, and gingival margin at the cementoenamel junction. They were divided into four groups of 20 teeth each and were restored accordingly: Group I – Bulkfill nanohybrid; Group II – Nanofill; Group III – Ormocer; Group IV – microhybrid composites. Each group w...

Reattachment of the tooth fragment is an ultraconservative technique for managing coronal tooth fractures when the tooth fragment is available, and there is minimal violation of the biological width. The advances in adhesive dentistry have allowed dentists to use the patient's own fragment to restore the fractured tooth which provides fast and esthetically pleasing results. This article reports fragment reattachment technique and presents two clinical cases of complicated crown fracture.