Analysis of the Importance of the Motion Used in the Resistance of Different Mechanical Instrumentation Systems in Endodontics: A Comparative Study

Aim: The aim of this study was to compare the cyclic fatigue strength of different reciprocating rotary systems depending on the movement used. Methods: Four study groups were analyzed (n = 30): (1) Reciproc(®), (2) Reciproc Blue(®), (3) Wave One Gold(®) and (4) Procodile(®). Each group was divided into three subgroups according to the motion used: (A) Reflex Dynamic(®) (n = 10), (B) ReFlex Smart(®) (n = 10) and (C) conventional reciprocating motion (n = 10). They were used in a dynamic cyclic fatigue prototype until their fracture, and the time was measured in seconds. The results obtained were analyzed with the ANOVA method, and for two-to-two comparisons, the Tukey method and Weibull statistics were used. Results: Procodile ReFlex Smart had the longest time to failure, and statistically significant differences were found between Procodile ReFlex Smart and the other files and motions (p < 0.05). Conclusion: Smart motions increase cyclic fatigue strength. ReFlex Smart(®) motion increases the cyclic fatigue strength of reciprocating rotary systems, and Procodile(®) ReFlex Smart was the most resistant system file.