A Comparative Examination of Cyclic Fatigue and Fragment Length of Three Different Types of Endodontic Rotary Files: An In Vitro Study

Introduction: Although of great scientific advancement in the properties and form, fracture of nickel-titanium (NiTi) files could occur during their use. The goal of this study was to compare resistance to cyclic fatigue of various rotary systems used in endodontics. Materials and Methods: Three types of NiTi rotary systems were tested – group A: One Curve, group B: Edge File, and group C: lusterdent NiTi files. In these files, taper is 0.06, and their diameter is 25 mm. Stainless steel block was used. This block contains artificial canals with a 60o curvature, 5 mm radius of curvature, 21 mm length, and 1.5 mm width. A number of cycles before fracture were obtained and measurement of fragment length was achieved. Statistical evaluation of readings was accomplished with ANOVA and Tukey post hoc test. Results: There were statistically significant differences between the three types of NiTi rotary systems considering the number of cycles before file fracture (P < 0.001). The differences between fracture lengths were not statistically significant (P = 0.15). Conclusion: The Edge File revealed the highest cyclic fatigue resistance.