Comparative Evaluation of The Shaping Ability of The Three Nickel-Titanium Rotary Instruments Using Cone-Beam Computed Tomography.

The aim of this in vitro study was to compare the canal transportationand centering ability of three nickel-titanium rotary systems HyFlex EDM, Protaper NEXT and Mtwo, using cone-beam computed tomography (CBCT). A total of 45 extracted maxillary first molars with completely formed apices that were extracted due to severe periodontal problems were selected for this study and distributed into 3 groups (n=15). The samples were prepared with HyFlex EDM, Protaper NEXT and Mtwofiles. The centering ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The ANOVA test was used for statistical analysis. The level of significance was set at 0.05. Canals prepared with HyFlex EDM showed minimum values for root canal transportation at all the three levels which may be attributed to its unique cross section design. Maximum canal transportation was observed with MTwo in the coronal and middle thirds.