Evaluation of Cyclic Fatigue Resistance of Three Different Niti Rotary Systems-An Invitro Study

Abstract

Aim: The aim of this study is to compare and evaluate the cyclic fatigue resistance of 3 different Nickel Titanium rotary file systems: Hyflex CM, Neoendo Flex files and ProTaper Gold by static method in three different curvatures, namely, 45º,60º and 90º. Materials and Method: Thirty Hyflex CM (25/.06), Thirty Neoendo Flex (25/.06) and Thirty Protaper Gold (25/.08) instruments were included in this study. The static cyclic fatigue test was performed using a custom-made jig. The artificial canal is made of stainless steel jig with an inner diameter of 1.5mm, a 450, 600, 900 angles of curvature and radii of curvature of 5 mm. All the instruments were rotated according to manufacturer’s recommendations until failure occurred. The time taken to failure was recorded in seconds for each group using a digital chronometer. The data were analyzed statistically using one way ANOVA, Post hoc test of Bonferroni was performed to identify pair-wise significance via SPSS 21.0 software (SPSS Inc, Chicago, IL). The statistical significance was set at 5%. Result:In 45º and 60º Hyflex CM and Neoendo Flex are better than Pro Taper Gold. At 90º, Neoendo Flex is better than Hyflex CM (P< .05) Conclusion: Within the limitation of this study, it can be concluded that, Neoendo Flex files exhibited highest cyclic fatigue resistance at 90º angle of curvature. In 45º and 60º angle of curvature Neoendo Flex files and Hyflex CM rotary instrument were more resistant to cyclic fatigue. Protaper Gold showed the least cyclic fatigue resistance than the other files tested.