Aim: This study aimed to compare the cyclic fatigue of EdgeFile, ProTaper Gold, OneShape, and ProTaper nickel-titanium rotary instruments.
Materials and methods: F2 ProTaper Universal and ProTaper Gold (Dentsply, Tulsa Dental Specialties, Tulsa, OK, USA), C2 EdgeFile (EDGEENDO, Albuquerque, NM, USA), and size 25 OneShape (Micro-Mega, Besançon Cedex, France) (15 instruments each group) were tested for cyclic fatigue in an artificial canal with a 6-mm radius and a 45° curvature. The number of cycles to fatigue (NCF) was recorded, the lateral surface and fractured face of segments were examined using scanning electron microscopy (SEM), and the cross-sectional area was measured. One-way ANOVAs and Games-Howell tests were utilized for data analysis. A significant difference was set at 0.05.
Results: The EdgeFile had significantly greater resistance to cyclic fatigue, compared with the ProTaper Gold, OneShape, and ProTaper Universal (p<0.05). No significant difference was found between the OneShape and ProTaper Gold (p>0.05), and the ProTaper Universal exhibited significantly lower resistance to cyclic fatigue compared to the other systems (p<0.05). The OneShape had a significantly smaller cross-sectional area (p<0.05), while no significance differences were found between the cross-sectional areas of ProTaper Gold, EdgeFile, and ProTaper Universal (p>0.05). No significant differences were found among the groups regarding the length of the fractured segments (p>0.05).
Conclusion: EdgeFile rotary files have superior resistance to cyclic fatigue, followed in order by the ProTaper Gold, OneShape, and ProTaper Universal rotary files.