Shaping Ability of NiTi Rotary versus Stainless-Steel Hand Instruments in Curved Root Canals of Extracted Teeth

Introduction: The purpose of this in-vitro study was to compare shaping ability of NiTi rotary Mtwo and FlexMaster with stainless steel hand K-Flexofile in curved root canals of extracted teeth. Materials and Methods: Mesiobuccal canals of 45 mandibular molar teeth were balanced into three groups of 15 each, with respect to the Schneider angle, canal access angle, height, dis-tance and radius of canal Curvature. Canals were prepared with Mtwo, FlexMaster and stainless steel hand K-Flexofile according to the manufac-turers` instruction. Comparing pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined using AutoCAD program. Data was analyzed using one way ANOVA and Tukey HSD test. Results: After instrumentation, the K-Flexofile system was significantly different from Mtwo and Flex Master systems for the mean difference of Schneider angle (p=0.0001, p=0.0001), canal access angle (p=0.006, p=0.003), radius (p=0.045, p=0.015) and distance of curvature (p=0.001, p=0.001). Conclusion: Mtwo and FlexMaster files main-tained the original canal curvatures better than the K-Flexofile