Analysis of dynamic cyclic fatigue resistance of different endodontic nickel-titanium instruments with different sterilization methods: An in vitro study.

Abstract

Aim: This study aimed to evaluate the influence of autoclave sterilization on the cyclic fatigue resistance of nickel-titanium (NiTi) endodontic files with different NiTi alloy treatments.

Materials and methodology: The research examined Hyflex CM, Bassi Logic, TruNatomy, and ProTaper Gold files, which were divided into control, conventional sterilization, and flash sterilization groups. Poststerilization, the instruments were tested using a custom-made Dynamic Cyclic Fatigue Testing Device replicating root canal procedures. Group 1 used HyFlex CM (size 25, taper 0.04), Group 2 used Bassi Logic (size 25, taper 0.04), Group 3 used TruNatomy (size 25, taper 0.04), and Group 4 used ProTaper Gold (size F1). After rotating each instrument until it fractured, the number of cycles to failure was determined and the time to fracture was noted.

Statistical analysis: Statistical analysis was conducted using SPSS 26.0 (Statistical software developed by IBM) with one-way ANOVA and Tukey honestly significant difference post hoc tests.

Results: HyFlex CM had the highest fracture resistance, whereas ProTaper Gold had the lowest. Sterilization increased the cyclic fatigue resistance of HyFlex CM, Bassi Logic, and ProTaper Gold but decreased that of TruNatomy.

Conclusion: The study concluded that sterilization enhances cyclic fatigue resistance, except for TruNatomy files, and emphasized understanding NiTi alloy properties to mitigate instrument failure.