Iranian Endodontic Journal

Abstract

Introduction: The aim was to compare the cyclic fatigue resistance and the macroscopic, microscopic, and elemental characteristics of three reciprocating endodontic systems. Materials and Methods: An in vitro experimental study was conducted with 3 groups (n=20): WaveOne Gold (WOG), Roll Wave Blue (RWB), and TF4 Gold (TF4). Cyclic fatigue resistance was assessed using a custom device with artificial curved canals and an endodontic motor operating in reciprocating motion. The fracture time (FT), in seconds, and the number of cycles to fracture (NCF) were the parameters evaluated in this analysis. Macroscopic analysis was performed using macro photography to assess the pitch, its distribution along the instrument, and the cutting edges. Microscopic analysis was performed using scanning electron microscopy (SEM) to examine surface and cross-sectional features. Additionally, energy-dispersive X-ray spectroscopy (EDX) was used to determine the elemental composition. Data from the cyclic fatigue analysis were analyzed using the Kruskal–Wallis test and Dunn's post hoc test (α=0.05). Results: RWB showed the highest resistance to cyclic fatigue, with higher FT and NCF values. The pitch and its distribution differed among all groups. SEM analysis revealed a higher loss of cutting-edge sharpness on TF4 instruments and greater tip deformation on WOG when used. EDX analysis showed no significant differences in elemental composition among the systems. Conclusion: RWB demonstrated superior cyclic fatigue resistance. Additionally, the systems had similar chemical compositions but differed in performance, which could be associated with variations in their alloy characteristics, design, and heat treatment.