Comparison of the cyclic fatigue resistance of the original reciproc files with equipollents

Aim: In this study, cyclic fatigue resistance of Reciproc R25, Golden Star RC, NIC RC and RO files were compared. The present study aimed to compare the cyclic fatigue strength of the original RC files and their equivalent GS, NIC and RO files. Material and Methods: In this study, 100 files, 25 in each group, were subjected to cyclic fatigue test on the artificial canal on stainless steel block with 60(degrees) curvature, 5 mm radius and 1.5 mm depth. The files in all groups were rotated until they were broken in the artificial canal using the Reciproc ALL program. The time to break was recorded with a 1/100 second precision stopwatch for each file and the total number of rounds was calculated. Number of rounds of files and the lengths of fractures were recorded then evaluated statistically (P<.05). The files were examined by scanning electron microscopy (SEM) images to evaluate the fracture type. Results: As a result of the data obtained from the study, the RC file was statistically the most resistant to cyclic fatigue (p <.05). GS and NIC files were found to be more resistant than RO (p <.05). Discussion: Based on the data derived from this study, it is evident that the RC file exhibited the highest cyclic fatigue resistance, as indicated by statistically significant results. In comparison, GS and NIC files displayed greater resistance to cyclic fatigue than RO files. The examination of SEM images further corroborated the presence of cyclic fatigue fractures in the tested files. Notably, GS, NIC, and RO files, despite sharing a similar shape with the RC, failed to match the original RC file's level of resistance against cyclic fatigue, underscoring the importance of considering file composition and heat treatment in enhancing resistance.