The Impact of Multiple Autoclave Cycles on the Surface Roughness of Thermally Treated Nickel-Titanium Endodontic Files

In this study, we evaluate the surface roughness (SR) of three thermally treated nickel-titanium rotary instruments (i.e., TruNatomy [TN], ProTaper Gold [PTG], and EdgeTaper Platinum [ETP]) after impact testing with multiple autoclave sterilization cycles using scanning electron microscopy (SEM). Overall, 60 files were sourced 20 TN, ETP, PTG files), each group was divided into four equal subgroups five (n = 5). An unsterilized assigned as pre-autoclaving (Cycle 0), other groups underwent various (Cycles 1, 5, 10). The average (Ra), root mean square (Rq), maximum peak-to-valley height (Rz) values evaluated SEM ImageJ software. Shapiro–Wilk test, one-way analysis variance, post-hoc Tukey test used to analyze data. statistical significance level set at p < 0.05 . Before autoclaving, all showed debris SR but no statistically significant differences existing between groups. decreased one autoclaving cycle for instruments. After cycles, Rz value ETP higher compared TN. 10 Ra Rq TN PTG. These results suggest that influence PTG, showing levels irregularities than