Shaping Ability of the Fifth Generation Ni-Ti Rotary Systems for Root Canal Preparation in Curved Root Canals using Cone-Beam Computed Tomographic: An In Vitro Study

BACKGROUND: Various root canal systems are available commercially with each manufacturer stating superior characteristics of their respective systems. The fifth generation root canal systems claim to have better flexibility and superior debris elimination due to their offset design. This study aims to compare the effects of fifth generation rotary systems on canal curvature, transportation and centering ratio of curved mesial root canals of mandibular molar via cone-beam computed tomographic (CBCT) imaging. MATERIALS AND METHODS: With curvature ranging from 20° to 40°, 60 mandibular first molars with mesiobuccal root angle were divided into three groups with 20 canals each. Before instrumentation, the groups were balanced with respect to the angle of canal curvature based on CBCT images taken. All root canals were shaped to an apical size of 25: OneShape (OS) (Micro Mega, Besancon, France), ProTaper Next (PTN) (Dentsply Maillefer), Revo S (RS) (Micro Mega, Besancon, France). CBCT assessment was done post instrumentation. SPSS version 16 software was used for statistical analysis. The significance level was set at P = 0.05. RESULTS: The RS system maintained better canal centricity and less transportation as compared to PTN and OS. There was no significant difference among the three groups in canal curvature after instrumentation. CONCLUSIONS: All file systems used straightened the root canal curvature similarly. RS instrumentation exhibited superior performance compared with the OS and PTN systems with respect to transportation and centering ratio.