Comparative evaluation of accuracy of working length determination with fifth-generation apex locator using two different techniques: An in vitro study.

Context: Accurate working length (WL) determination is essential for successful root canal therapy. Aim: The aim of this study was to compare the difference between two different techniques in locating minor constriction using fifth-generation electronic apex locator. Settings and Design: A detailed protocol explaining the procedures of the study was submitted to the institutional ethics committee. Subjects and Methods: Forty extracted human permanent canine teeth were selected. WL was measured three times for each sample by three different examiners for both the conventional and experimental techniques at different time intervals. Interexaminers were blinded to their measurements, and the person who analyzed mean value was also blinded with techniques. Finally, radiographic working length was obtained using 15 size K-file. A size 20 K-file was cemented into the measured position with glass ionomer cement. Each tooth was viewed under a stereomicroscope at ×40 magnification. The distance from the file tip to the root apex was measured and calibrated to the nearest tenth of a millimeter. Statistical Analysis Used: Using Stata statistical software (Version 17, Statacorp, College Station, Texas, USA). The agreement between raters and techniques was determined using intraclass correlation coefficient "ICC" and Bland-Altman plot. Results: The "experimental method" (0.95, 95%) showed better agreement between the raters in comparison with the "conventional method" (0.93, 95%). Conclusions: The experimental technique showed perfect agreement between examiners in locating the minor constriction of the apical foramen.

The efficacy of lining materials in the reduction of microleakage in class II composite resin restoration using the sandwich technique: A stereomicroscopic study.

Background: The sealing ability of different liners under composite restorations in the reduction of microleakage. Aim: To evaluate the effects of three different liners in sandwich techniques on gingival microleakage of class II composite restorations. Materials and Methods: Standardized Class II box cavities were prepared on forty premolar teeth and randomly divided into four groups, n = 10: Group A, no liner (control); Group B, Polofil NHT Flow; Group C, Ionolux; and Group D, Fuji VII. The etching, bonding, and process for restoring the whole remaining mass of the cavities with G-aenial composite were the same, with the sandwich material expectations. Dye penetration was evaluated using a stereomicroscope. Statistical Analysis: Duncan's Post hoc analysis and Friedman's test. Results: Group A showed the highest microleakage followed by Group D, Group C, and Group B. Conclusion: Polofil NHT Flow seems to be a promising liner for gingivally deep class II cavities.