Comparison of Dentinal Microcracks Formation Using Two Different Rotary Systems and Hand Instruments

Introduction: The endodontic success is attributed to a variety of factors, but one of the most important is canal preparation. Among causes of endodontic failures is vertical root fracture, which may result from gradual propagation of initial dentinal defects. Radicular canal preparation with hand instruments or with rotary systems seems to play an important role in initiation of dentin defects which later can propagate to vertical root fractures. Aim: The aim of this study was to compare the incidence of dentinal microcracks after instrumentation with Neolix, SCpro and hand instrumentation. Materials and method: 40 freshly extracted human maxillar centrals were collected and stored in formalin solution for two weeks. 40 samples collected were divided into four groups with ten teeth in each. Group 1 – unprepared root canal shaping group (control group), group 2 – hand instrumentation, group 3 – prepared by Neolix and group 4 – prepared by SCpro (SOCO). All teeth were cut by diamond disc in cervical one third of root and inspected under XJM300 KOZO microscope. Results: The highest number of microcracks was found in root canals prepared with SCpro and only one was found in a root canal prepared with Neolix. No cracks were observed in the control group and hand instrumentation group. Conclusion: Rotary instruments caused dentin defects compared to hand instrumentation which didn’t cause any defects in radicular dentin. SCpro rotary system caused more dentinal damage compared to Neolix. Considering the extent of dentinal microcracks, Neolix rotary system can be considered a safe alternative to hand instrumentation.