Cyclic Flexural Fatigue Resistance of the Revo-s Rotary Nickel-titanium Endodontic Files

Resistance to cyclic flexural fatigue failure is an important feature of rotary nickel-titanium (NiTi) instruments. The aim of this study was to evaluate the cyclic flexural fatigue failure resistance of RevoS Shaper Universal rotary NiTi files and to compare it to two other rotary NiTi files with similar size and taper, the Hero Shaper and the ProFile. Fifteen each of Revo-S Shaper Universal, Hero Shaper, and ProFile rotary NiTi files all with the same tip diameter and taper (ISO size 25 with 0.06 taper) were assessed. The time to failure during cyclic flexural fatigue testing was recorded. The mean time to cyclic flexural fatigue failure was 96.1 + 17.3 seconds for the Revo-S Shaper Universal, 120.5 + 24.3 seconds for the Hero Shaper, and 154.6 + 14.9 seconds for the ProFile. Differences among all three groups were statistically significant (P = 0.001). The Revo-S Shaper Universal rotary NiTi files were less resistant to cyclic flexural fatigue failure than the Hero Shaper and the ProFile files with similar tip diameter and taper.