The Effect of Temperature on Cyclic Fatique Resistance of Different Heat-Treated İnstruments in Curvature Canals

Aim: To compare the cyclic fatigue resistance of different heat- treated rotary files in single curvature canals, taking into account the intracanal temperature (ICT) and room temperature. Material and Methods: Cyclic fatigue resistance of ProTaper Next, One Curve, 2Shape, Reciproc Blue, rotary-file-systems, using the immersion method, at ICT (37°C) and RT (20°C) tested in distilled water. A total of 120 files were used, thirty files from each file system. Artificial canals were obtained using stainless steel. The curvature radius of the artificial canals is 5 mm and the curvature angle is 60°. The fracture duration and fragment length of every file were recorded, and the data were analyzed statistically. Results: One Curve has the highest cyclic fatigue resistance at 37°C, while Reciproc Blue has the highest fatigue resistance values at 20°C. The increase in temperature only decreased the cyclic fatigue resistance of the 2Shape file system. Conclusion: The kinematics of NiTi rotary files and heat-treatments applied to the files affect the cyclicfatigue-resistance. C wire and Blue alloy notably increases the cyclic fatigue resistance collated with T wire and M wire alloy at ICT.