Secondary Dentin as an Aid in Gender Predilection: A Forensic Study

Background Forensic odontology deals with age, sex, and race determination of the deceased at crime scenes, disasters, or natural calamities. Studies regarding the role of secondary dentin in age estimation have been documented on a several occasions in the literature but use of secondary dentin in gender predilection has not yet been documented. So, the present study was aimed at using the secondary dentin as a diagnostic tool in gender predilection. Materials and Methods The study included a total of 20 samples (10 males and 10 females). Extracted teeth were collected and placed in 10% neutral buffered formalin solution. The sections were ground on Arkansas stone until the appropriate thickness of the ground sections was achieved. The freshly prepared ground section was mounted on a slide using DPX mounting media. Ground sections were visualized under a microscope and the thickness of secondary dentine was measured using the image analysis software. Results The data were collected and subjected to group statistics. The secondary dentin thickness of all the samples, males and females, was measured. It was observed in our study that the mean thickness of secondary dentin was more in male samples (0.2970) with the standard deviation of 0.01494, as compared with that of females where the mean thickness was found to be 0.1970 with the standard deviation of 0.02058. Conclusion This study has shown that variation in secondary dentin thickness does exist between male and female groups. This criterion can be considered as an aid for gender determination in the future.

Residual Dentin Thickness in Bifurcated Maxillary Premolars after Cervical Preflaring Preparation: A CBCT Analysis

Objective: This study evaluated the residual dentin thickness (RDT) of maxillary premolars after the use of different cervical preflaring (PF) drills by using cone-beam computed tomography (CBCT). Methods: Eighty bifurcated maxillary premolars were accessed and randomly divided into 5 groups (n=16). PF was performed with Gates-Glidden #1, #2, and #3 (group 1), Largo #1 and #2 (group 2), and LA Axxess #20/.06 (group 3), #35/.06 (group 4), and #45/.06 (group 5). CBCT images were acquired before (preoperative) and after (postoperative) PF. Initial and final cervical dentin thickness was measured at the buccal, palatal, mesial, and distal aspects, 0.5 mm coronally to the furcation, on both buccal and palatal roots, using CBCT’s image analysis software. The percentage of removed dentin after PF preparation was also calculated. Data were analyzed using ANOVA followed by Tukey’s test at a significance level of P < 0.05. Results: No statistically significant differences were found among the groups for preoperative or postoperative RDT (P > 0.05). LA Axxess #20/.06 (group 3) removed significantly less cervical dentin at all root canal aspects on both buccal and palatal roots. The mesial aspect of the buccal root and distal aspect of the palatal root were significantly reduced after the use of LA Axxess #45/.06 (group 5) and Largo #1 and #2 drills (group 2), respectively (P < 0.05). Conclusion: PF in bifurcated maxillary premolars should be performed with LA Axxess instrument #20/.06. The use of Gates-Glidden #1, #2, and #3, Largo #1 and #2, and LA Axxess #45/.06 drills should be done with caution.

Influence of Varying Dentin and Enamel Layer Thicknesses of Nano-composite Resins on Color Match between Lithium Disilicate Dental Ceramic and Composite Resins

Objectives: The aim of this study was to evaluate the influence of varying dentin and enamel layer thicknesses of two nano-composite resins on color match of composite resins and lithium disilicate dental ceramic. Materials and Methods: Twenty-six specimens of two types of nano-composite resins, Opallis and Vittra, were fabricated using the two-layered technique with different thickness ratios of enamel and dentin composites (A2 shade) with a total thickness of 1.2mm. Thirteen discs of the same shade and thickness of IPS e.max Press LT (low translucency) lithium disilicate dental ceramic were also fabricated. Specimen color was measured with a spectrophotometer. The difference in color (ΔE00) of composite and ceramic specimens, and the translucency parameter (TP) of all specimens were calculated. Data were analyzed using multi-factor ANOVA (P<0.05). Results: The color difference (ΔE00) values of composites and ceramic were not clinically acceptable in any areas of either of the two composites (ΔE00>2.25). But ΔE00 between the two composite resins was in the clinically acceptable range (ΔE00<2.25). The mean TP value of IPS e.max Press was greater than that of Vittra and lower than that of Opallis. Conclusion: In similar thicknesses, composite resins with any enamel/dentin thickness ratio could not successfully simulate the color and translucency of IPS e.max Press LT ceramic.

Pilot Study of Tooth Structure Removed in Primary Molar Zirconia Crown Preparations of Typodont Teeth

Prefabricated zirconia crowns (ZRCs) require a passive fit and more reduction than stainless steel crowns (SSC). To determine the mean and maximum reduction depths in the mesial-buccal and occlusal areas for three ZRC brands and one SSC in posterior primary typodont molars and to compare reduction depths to existing literature to determine the preparation’s proximity to pulpal tissue. Four primary maxillary and mandibular typodont teeth (J and S) were prepared according to the manufacturers’ guidelines for three ZRCs and an SSC. The teeth were scanned before and after preparation with an optical scanner, and the mean and maximum depths of reduction for each tooth were calculated in triplicate with custom software and statistically compared among the types of crown. The results were compared to existing data on primary tooth enamel and dentin thickness. Maximum mesial-buccal and occlusal depth respectively of preparation for any ZRC for tooth J was 1.19 mm and 1.58 mm while for tooth S it was 1.06 and 2.07mm Both EZ Crowns and Kinder Krowns required an additional 0.5mm occlusal reduction beyond the manufacturer’s recommendation for tooth S. Ideal preparations of ZRCs require more reduction than SSCs. Both EZ Crowns and Kinder Krowns require more reduction than the manufacturer’s recommendation for a mandibular first primary molar.