Shaping Ability of Three Nickel-Titanium Endodontic File Systems in Simulated S-shaped Root Canals

Introduction: The purpose of this study was to determine the shaping ability of 3 nickel-titanium (NiTi) endodontic file systems by measuring canal transportation. Methods: Seventy-two S-shaped canals in resin blocks were randomly allocated into 3 groups (n = 24): the Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel) group, the Typhoon group (Typhoon rotary files with Controlled Memory Wire; DS Dental, Johnson City, TN), and the Vortex group (ProFile Vortex rotary files with M-Wire NiTi; Dentsply Tulsa Dental Specialties, Tulsa, OK). Blocks were secured in a jig for imaging standardization and instrumentation stabilization. Gates Glidden and Path File drills (25 mm/.02 taper) were used to prepare the glide paths. For the Typhoon and Vortex groups (25 mm/.04 taper), canals were flooded with sterile water and instrumented using a crown-down technique from sizes 40 to 20/.04 and then apically enlarged to size 30/.04. The SAF group (25 mm) was instrumented with constant sterile water irrigation in a light-pecking, transline motion. Pre- and postinstrumentation images were taken at 40x magnification and layered, and canal transportation was measured. Results: After adjusting for the level and canal wall side, the mean transportation was significantly higher for the Typhoon (P < .001) and Vortex (P = .005) groups compared with the SAF group. Additionally, the mean transportation was significantly higher for the Typhoon group versus the Vortex group (P < .001). Conclusions: Under the conditions of this study, SAFs showed less canal transportation than ProFile Vortex and Typhoon files in simulated S-shaped root canals. (J Endod 2012;38:1618-1621)