Cyclic Fatigue of Glide Path Rotary NiTi Files in a Double (S-Shaped) Simulated Curvature

Objective: The aim of the present study was to compare the fatigue resistance of PathFile (PF) and ProGlider (PG) NiTi (Nickel-Titanium) rotary files in a double (S-shaped) curvature artificial root canal.Methods: The cyclic fatigue of the following rotary NiTi glide path instruments was tested in a double curvature artificial canal, PF (tip size .16 and .02 taper) and PG (tip size .16 and variable taper). Twenty instruments for each group were tested to fracture in continuous rotary motion at 300 rpm. The number of cycles to failure (NCF) was calculated and the length of the fractured fragment was measured. Data were statistically analyzed with a level of significance set at 5%.Results: There was no significant difference in cyclic fatigue resistance between the PF and the PG in the apical curvature (pu003e0.05). However, in the coronal curvature the NCF value was significantly higher for the PG than for the PF (p 0.05).Conclusion: The instruments were found to be less resistant to cyclic fatigue in the apical curvature of the artificial canal than in the coronal curvature. PG instrument showed significantly greater cyclic fatigue resistance in the coronal curvature.