Sealing Capacity of Bulk-fill Resin in Endodontically Treated Teeth.

AIM: The objective of the study is to evaluate the cervicalapical sealing of bulk-fill flow resins associated with a universal adhesive system, in endodontically treated teeth, considering two methods of evaluation. MATERIALS AND METHODS: The samples used in the bacterial leakage analysis were autoclaved, filled inside a laminar flow chamber, and divided into four experimental groups (n = 8) according to the restorative material: Filtek Bulk-fill flow; Surefil SDR flow; TetricEvoflow and the positive control. The samples were inoculated with the Enterococcus faecalis (E. faecalis), every 7 days and the microleakage was evaluated on a daily basis for 60 days. Microleakage tested with dye (n = 5) was considered in 2-time intervals of evaluation (24 hours and 72 hours), and the results were obtained in scores from 0-5. Data were submitted to the statistical tests, at a level of significance of 0.05. RESULTS: About 12.5% of the FBF specimens showed bacterial microleakage as from the thirteenth day, and SDR, from the 20th day. TEF presented the highest percentage of microleakage at 40 days, concluding the 60 days with 37.5% of viable specimens. The Log-rank test revealed that the survival curve of TEF was statistically significant in comparison with those of the other groups. In the test with dye TEF and SDR presented the highest and lowest rate of microleakage, respectively, with statistically significant differences in the time interval of 72h. CONCLUSION: The resins FBF, SDR, and TEF were incapable of promoting the hermetic sealing of fillings in the root canal system. CLINICAL SIGNIFICANCE: No bulk-fill flux studied was able to completely eliminate microleakage, despite the best performance with respect to the microleakage time presented by Filtek Bulk fill, followed by Surefil SDR flow.

Canal Transportation, Centering Ability, and Dentin Removal after Instrumentation: A Micro-CT Evaluation.

AIM: The aim of this study is to evaluate and compare root canal transportation, centering ability, and amount of dentin removed after root instrumentation with different rotary and reciprocating systems, using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Forty curved mesial canals of lower molars were selected and divided into four experimental groups (n = 10) according to the system used: protaper next (PTN), wave one gold (WOG), prodesign logic (LOG), and vortex blue (VTX). The roots were scanned before and after instrumentation using micro-CT, with a 16 µm isotropic resolution. RESULTS: Data were statistically analyzed using the Bioestat and the significance level was set at 0.05. For canal transportation, no significant differences were verified between the groups at 6 mm or 9 mm from the apex. At the apical third, LOG had a smaller mesial deviation when compared with PTN. A significant difference was found at the apical and coronal thirds, though with LOG having the best centering ability at the apical third and the worst one at the coronal third. All systems caused a greater wear at the coronal third (9 mm), decreasing at the apical one (3 mm), with statistically significant differences. LOG removed less dentin from the apical third (3 mm) than did the other instruments. CONCLUSION: The systems evaluated presented different results for canal transportation, centering ability, and dentin removal at each third. CLINICAL SIGNIFICANCE: The systems were evaluated together to evaluate neither the marked dental deviations nor the long-term signifiers of the databases and they were evaluated within the limits of normality. Therefore, they can be used without risks of embrittlement of the dental roots.