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

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. 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. 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). Mtwo and FlexMaster files main-tained the original canal curvatures better than the K-Flexofile