Optimization of difficult endodontic treatment with nickel-titanium files in martensitic and austenitic phase

INTRODUCTION . Nickel-titanium alloys and cutting-edge design of endodontic files continue to revolutionize. In addition to variations in the design of nickel-titanium files, manufacturers have implemented several proprietary manufacturing processing procedures to improve their mechanical properties. AIM . The aim of the study was to improve the quality of mechanical instrumentation of highly curved root canals based on the data of laboratory and experimental analysis of rotary endodontic instruments made of nickel-titanium alloys of various modifications. MATERIAL AND METHODS . As part of the research, the following endodontic rotary files systems were studied during instrumentation of curved root canals: group 1 – Mtwo (VDW); group 2 – Race Evo (FKG), group 3 – Ultrataper next (Eurofile). A metallographic analysis of the instruments was performed, a morphological structure of the root dentin after instrumental was examined by scanning electron microscopy, as well as the amount of extruded debris was studied. RESULTS . Groups 2 and 3 showed significant deterioration after three applications. Mtwo files showed a statistically higher amount of surface damage after five uses (p < 0.05). The smallest amount of extruded debris was found in the group 2, while the largest number of root dentin irregulations was found in the groups 1 and 3 (p < 0.001). CONCLUSIONS . A different degree of the surface damage of the instruments was revealed, depending on the number of treated root canals. The safest and most effective endodontic system for the mechanical preparation of curved root canals is the Race EVO.