Can Measurement of Cyclic Fatigue Resistance for Titanium-Molybdenum Alloy as Rotary Endodontic Files (An In vitro Study)
Purpose: This study aims to evaluate the cyclic fatigue resistance of Ti-Mo alloys and compare them with conventional and heat-treated NiTi alloys. Materials: Sixty new brand rotary files (EndoSequence, Endostep, 2shape, Mono2 gold, and TMA) were divided into two main groups (symmetrical and asymmetrical) according to cross-sectional designs. All samples have the same size (25/04) rotated inside the simulated stainless-steel canal. The artificial canal was (+ 0.1 mm) wider than the size of the tested instruments, (5 mm) radius of curvature, (5 mm) curvature center from the instrument tip, and (45°) angle of curvature. The time of fracture was recorded in seconds via iPhone mobile, and the number of cycles to fracture (NCF) for each file was measured. One way-ANOVA, Tukey’s HSD were performed, and statistical significance was set at P < 0.05. Results: In symmetrical groups, (NCF) value showed that EndoSequence was significantly highest cyclic fatigue resistance, followed by Endostep and TMA. While in asymmetrical groups, (NCF) value showed that Mono 2 gold was the highest cyclic fatigue resistance, followed 2 shape and TMA. Conclusion: Within the limitations of the present study, it was concluded that the cyclic fatigue resistance of NiTi rotary files was higher than Ti-Mo rotary files.