Cyclic fatigue resistances of several nickel-titanium glide path rotary and reciprocating instruments at body temperature.

AIM: To compare the cyclic fatigue resistance of the One G, ProGlider, HyFlex EDM and R-Pilot glide path NiTi files at body temperature.

METHODOLOGY: Twenty One G (size 14, .03 taper), 20 ProGlider (size 16, .02 taper), 20 HyFlex EDM (size 10, .05 taper) and 20 R-Pilot (size 12.5, .04 taper) instruments were operated in rotation at 300 rpm (One G, ProGlider and HyFlex) or in reciprocation (R-Pilot) at 35 °C in artificial canals that were manufactured by reproducing the size and taper of the instrument until fracture occurred. The time to fracture was recorded in seconds using a digital chronometer, and the length of the fractured fragments was registered. Mean data were analysed statistically using the Kruskal-Wallis test and post hoc Tukey tests via SPSS 21.0 software. The statistical significance level was set at 5%.

RESULTS: The cyclic fatigue resistance of the R-Pilot files was significantly greater than the other instruments, and the One G was significantly lower (P < 0.05). There was no difference between the HyFlex EDM and the ProGlider (P > 0.05). No significant difference (P > 0.05) was evident in the mean length of the fractured fragments of the various instruments.

CONCLUSIONS: The cyclic fatigue resistance of the R-Pilot reciprocating glide path file was significantly greater than that of the rotary HyFlex EDM, ProGlider and One G glide path files.