Topography of root-end surface after freehand and three-dimensional-guided apicoectomy procedure: A scanning electron microscope study.

[BACKGROUND] Dentinal microcracks formed during apical resection may lead to increased susceptibility to root fracture and improper sealing of apical preparation that may negatively influence the outcome of endodontic microsurgery.

[AIMS] This study was performed to analyze the root-end surface for dentinal microcracks using a scanning electron microscope (SEM) after resection with high-speed bur and trephine drill.

[MATERIALS AND METHODS] Thirty extracted single-rooted maxillary premolar teeth were selected and randomly distributed into two groups ( = 15). Working length was established using a #15 K-type file. Canals were prepared with a rotary Ni-Ti system to size 30/0.06 using endomotor, irrigated with 3% sodium hypochlorite, dried with paper points, and obturated with gutta-percha cones using a single-cone technique. All samples were mounted on preformed molds and poured using a mixture of sawdust and gypsum. In Group A; tungsten carbide bur was used to perform a freehand apicoectomy. In Group B; a trephine drill was used with a three-dimensional guide to perform 3 mm of root resection. Apicoectomy was performed in both groups under a dental operating microscope. Resected root ends were inspected for microcracks using SEM. The Shapiro-Wilk and Mann-Whitney U-test were used for statistical analysis.

[RESULTS] Microcracks were observed in all samples in both study groups. Trephine drill produced more microcracks on the resected root surface compared to the use of high-speed tungsten carbide bur with a statistically significant difference ( < 0.05).

[CONCLUSIONS] The trephine drill used during targeted endodontic microsurgery produced more microcracks on the resected root dentine surface compared to the high-speed tungsten carbide bur used during freehand apicoectomy.