Comparison of cyclic fatigue resistance of original and counterfeit rotary instruments

Introduction: In recent years, with the advances in counterfeiting methods, counterfeit products have reached the dental market. The purpose of this study was to compare the cyclic fatigue resistance of original and counterfeit rotary root canal instruments. Materials and methods: The cyclic fatigue of original and counterfeit ProTaper F2 endodontic instruments was tested (n = 20) in 3 mm radius steel canals with a 60 degrees angle of curvature. The number of cycles to fracture (NCF) was calculated, and the data were subjected to the Student's t-test (alpha = 0.05). Results: The original instruments showed better cyclic fatigue resistance than the counterfeit ones (p < .001). The mean NCF was 483 +/- 84 for the original files and 186 +/- 86 for the counterfeit files. Conclusions: The cyclic fatigue resistance of the counterfeit instruments was very low. As a result, clinicians should be careful not to purchase counterfeit products.