Comparison of dynamic cyclic fatigue resistance of Reciproc® Blue and WaveOne® Gold after sterilization and/or immersion in sodium hypochlorite

This study aims to compare the cyclic fatigue resistance (CFR) of the Reciproc Blue and WaveOne Gold instruments under a dynamic cyclical fatigue test. 210 Reciproc Blue "R25" and WaveOne Gold "primary" files were assigned into 7 groups (n =15) for each brand. Groups G: Files were not exposed to NaOCl or sterilization. Groups A and D: files were immersed for 3 minutes in NaOCl 1 and 3 times, respectively. Groups B and E: Files were autoclaved 1 and 3 times, respectively. Groups C and F: files were exposed to both, NaOCl immersion and autoclaving 1 and 3 times, respectively. Subsequently, files underwent a dynamic CFR test. The chemical composition of the files' surface from Group G was analysed by energy-dispersive X-ray spectroscopy (EDS). Cyclic fatigue resistance time was statistically analysed using 1-way and 2-way analyses of variance (ANOVA) and T-test. A -value ≤0,05 was set to be statistically significant. There was a significantly higher CFR of RB files than WOG in groups A, B, C, D and G ( 0.05). There were no statistically significant differences between files in group F ( >0.05). RB files from groups B, C, D, E and F had significantly lower resistance than new ones (Group G) (