The effect of tapered master gutta-percha cone on apical seal of straight and curved root canals prepared with nickel-titanium rotary files.

Background: Gutta-percha has been the predominant root canal filling material which is developed with different taper. Canal obturation fixed with nickel-titanium (NiTi) instruments and tapered gutta-percha master cone and lateral condensation is advantageous because it is clinically effectual and appears to result in a radiographically acceptable outcome. The aim of this study was to determine the effect of tapered master gutta-percha cone on apical seal of straight and curved root canals using NiTi rotary files.

Materials And Methods: In this study total of 130 mandibular molars were selected and divided into six experimental groups ( = 20) based on the degree of root canal curvatures (0°-20°and 20°-40°) and the taper of master cones (0.02, 0.04, and 0.06). The roots were immersed in the bacterial leakage model and monitored daily for a period of 70 days. Data were analyzed using Kaplan-Meier approach, log-rank test, and Chi-square tests. < 0.05 was considered statistically significant.

Results: The microleakage in the 0°-20° canal curvature using 0.02- and 0.04-tapered master cones was similar and considerably <0.06-tapered master cone ( < 0.05). However, the microleakage in the 20°-40° canal curvature using 0.02- and 0.04-tapered master cones was more than 0°-20° and for 0.06-tapered master cone was <0°-20°, but there was no statistical difference between the use of 0.02-, 0.04-, and 0.06-tapered master cones ( > 0.05).

Conclusion: The lateral condensation filling technique using 0.02- and 0.04-tapered master cones is more effective in minimizing microbial leakage in straight canals than 0.06-tapered master cone.