MATERIALS AND METHODS: Sixty single-rooted permanent human teeth were chosen after considering the inclusion and exclusion criteria. The teeth were divided into two groups (n = 30). The test group was instrumented with TN files and the other with XPS according to manufacturer's instructions. CBCT images were taken before and after instrumentation to record the root canal distances from mesial, distal, buccal, and lingual borders of the root at 3, 5, and 7 mm distances from the root apex using a specific formula. Statistical analysis was done using the Statistical Package for the Social Sciences software program, version 20.0. The data were analyzed using the unpaired t test.
RESULTS: Both TN and XPS were safe for use in oval-shaped canals with moderate root curvature. However, the XPS showed higher buccolingual transportation as compared with TN at 3 mm from the apex and higher mesiodistal transportation at 3 and 5 mm levels from the apex as compared with TN.
CONCLUSION: Canal transportation has been detected in both systems; however, the values obtained were within the safe range (<0.3 mm). Overall, no significant difference was observed between TN and XPS (p > 0.05) in their canal transportation tendencies and centering ability.
CLINICAL SIGNIFICANCE: The study assesses the canal centering and transportation tendencies of the recently launched TN rotary system in extracted teeth with a combination of morphologies. The findings of the study are significant clinically as minimum transportation of the canal, minimal dentin removal, efficient disinfection, and three-dimensional obturation of the root canal are considered important factors in deciding the prognosis of endodontic therapy.
Methods: The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH2O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs (n = 42) of 1 ± 0.2 mm width were obtained from caries-free permanent human molars. Thirty dentine discs (n = 30) were randomly divided into 3 groups (n = 10): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO2. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs (n = 12) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment.
Results: Desensitizing agents' application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability (p < 0.05) when compared to RMGI XT VAR and LIQ SiO2. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules.
Conclusions: 2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO2.
METHODS: Case records of patients who underwent third molar extractions at the Prince Philip Dental Hospital in Hong Kong between 3 July 2012 and 22 June 2017 were evaluated retrospectively. Data extraction was performed for indications, clinical and radiographic findings, antibiotic treatment, postoperative complications, and treatment for postoperative infection. The odds ratio (OR) for postoperative infection was estimated.
RESULTS: In total, 1615 extracted over 5 years from 992 patient records were included in the final analysis. Antibiotics were prescribed postoperatively for 44% of the extractions. The overall infection rate was 2.05%. There was no significant difference in infection rates between the groups which underwent extractions with or without antibiotics (OR = .68; P = .289). We found a significantly higher risk for infections with increasing age (P = .002).
CONCLUSION: Infection rates after third molar extraction is minimal in the current setting, with no significant benefit from postoperative antibiotic prescription.
METHODS: Fifty-seven maxillary second primary molars were scanned using micro-CT. Teeth with three divergent roots were divided randomly (n = 15) according to instrument type (K file, MTwo®, and Reciproc® Blue). Teeth with root fusion were instrumented manually as a separate group (n = 12). Pre- and post-instrumentation micro-CT images were superimposed, and the instrumentation area (IA) and procedural complications were recorded.
RESULTS: No statistically significant differences in IA between file systems was observed in the non-fused teeth. The mean IA of fused roots was significantly lower than in the non-fused distobuccal (p = 0.003) and palatal (p 60%) occurred in both non-fused and fused primary teeth with fewer procedural complications observed after manual instrumentation.