In vitro comparison of cyclic fatigue resistance of heat-treated rotary nickel titanium TruNatomy and ProTaper Gold with non-heat treated ProTaper Universal on simulated extremely curved root canal

Objectives: The objective of the study is to compare cyclic fatigue resistance of heat-treated rotary nickel titanium TruNatomy and ProTaper Gold with non-heat treated ProTaper Universal on simulated extremely curved root canal. Methodology: Thirty heat treated rotary nickel titanium (NiTi) files were used for analysis in this study. Ten NiTi files were distributed to each group with a size of 25 and taper of 0.04. Group A (control group): ProTaper Universal (PTU), Group B: ProTaper Gold F1(PTG), Group C: TruNatomy (TN). The cyclic fatigue of the NiTi instruments were evaluated using a custom-made experimental setup. NiTi files were tested within simulated 90-degree curvature canal in a metal block until the files were fractured. Number of cycles to failure (NCF) was then measured for each instrument. The one-way ANOVA test and Post hoc Tukey test was performed as statistical analysis to compare the cyclic fatigue of different rotary file. P < 0.001 was considered statistically significant. Result: Group C (TruNatomy) showed the highest mean value which was statistically significant with Group A and Group B with P <0.001. Conclusion: Trunatomy showed the highest NCF & superior cyclic fatigue in simulated 90o curved canal than ProTaper Gold and ProTaper Universal.