Evaluation of cyclic fatigue resistance of modern Nickel–Titanium rotary instruments with continuous rotation

Abstract

Aim: The aim of present study was to compare cyclic fatigue resistance of three modern Ni–Ti instruments used with continuous rotation. Materials and methods: For this study 3 groups of rotating instruments with continuous rotation (HyFlex EDM, Twisted File Adaptive, Revo S SU) have been used, each group consisted of 20 files. The various groups were subjected to cyclic fatigue testing through an artificial metal device. A statistical analysis with Kruskal–Wallis test and Mann–Whitney test was performed. Results: There were statistically significant differences between the three groups. The HyFlex EDM instruments have a fracture resistance slightly higher than the Twisted file and far higher than Revo S SU. Conclusions: Modern Ni–Ti alloys increase resistance of the rotating instruments to cyclic fatigue.

Keywords

• Cyclic fatigue
• Nickel-Titanium
• Continuous rotation
• Rotary instruments