Surface Integrity of Root Ends Following Apical Resection with Guided Trephine Burs

Introduction: Targeted endodontic microsurgery may be performed utilizing trephine burs for apical root resection. The purpose of this study is to determine if guided root end resection using trephine burs produces cracks or fractures within the root. Methods: Twenty maxillary anterior and twenty mandibular molar mesial roots from extracted teeth were cleaned, shaped, and obturated. Each root was secured in a custom surgical guide using polyvinylsiloxane material and fastened to a benchtop vice. With continuous water irrigation, roots were resected with either targeted trephine burs (Biomet 3i, Palm Beach Gardens, FL) or multipurpose burs (Dentsply Maillefer, Johnson City, TN). Resected root ends were analyzed by four calibrated observers using light microscopy with a fluorescent filter and a dental operating microscope. Chi-square analysis was used to compare the two groups. Teeth were graded based on the presence, extent, and location of cracks.2Results: One (10%) anterior trephine-resected root demonstrated cracks, while three (30%) anterior multipurpose bur-resected roots had cracks. These findings were not statistically different (P = 0.264, Chi-square = 1.25). No molar teeth in either group had detectable cracks.