RESUMO
INTRODUCTION: This study aimed to evaluate the dynamic cyclic fatigue resistance of Reciproc Blue files subjected to brushing motion. METHODS: Twenty Reciproc Blue files (R25, VDW, Munich, Germany) were employed for chemical-mechanical preparation in root canals of 3D printed replicas of mandibular molars. The instruments were divided into two groups (n = 10): Group brushing motion, instrumentation with brushing motions; Group without brushing motion , instrumentation without brushing motions. Subsequently, the same instruments underwent cyclic fatigue testing using artificial canals consisting of a stainless-steel plate and an apical segment with a 45° curvature. Data regarding the time to fracture, number of cycles to fracture, and length of the fractured fragment were collected and subjected to statistical analysis using the t-test or Mann-Whitney test, with a significance level of 5%. Additionally, the fractured fragments were examined under a scanning electron microscope. RESULTS: No statistical differences were observed between the groups in terms of time to fracture (P < .05), number of cycles to fracture (P < .05) and length of the fractured fragment (P < .05). CONCLUSION: The brushing motion did not affect the dynamic cyclic fatigue resistance of Reciproc Blue files.
