Valutazione della resistenza alla fatica ciclica di strumenti rotanti a rotazione continua prodotti con moderne leghe Nickel-Titanio

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.