Accuracy of a minimally invasive surgical guide in microsurgical endodontics: a human cadaver study

Aim: In the last decade, endodontic microsurgery has achieved high qualitative standards and excellent success rates. Technology and highly innovative materials have reduced pre- and intra-surgical complexity. To date, operator experience continues to be an important prognostic factor. This study aimed to evaluate the accuracy of root resections achieved by two operators with different experience in endodontic microsurgery using a surgical guide. Methodology: A comparative study was conducted on 40 roots (20 roots/operator) in two defrosted cadaver heads. Preoperative CBCT and intraoral scans were used to plan and manufacture a bony-supported surgical guide equipped with oriented steel sleeves and buccal flanges. Two operators with different levels of endodontic skills and abilities execut- ed osteotomies and root resections. Planned and postoperative CBCT images were super- imposed to measure the linear deviation of the surgical access point from the planned target. A t-test was performed to compare linear deviations from the planned target between experienced and non-experienced operators. Statistical significance was set at 5% (p<0.05). Maximum length of resected apex, present and centred root canal, periodontal ligament, and sufficient osteotomy to complete the root-end preparation and filling were qualitatively evaluated by a third experienced surgeon. Results: Overall, the mean linear deviation was 1.23 ± 0.38 mm. No statistically significant differences emerged between operators, even in posterior teeth. All root resections were considered clinically successful. Conclusions: Guided endodontic microsurgery is an accurate and unbiased method to execute apical access, even in posterior teeth, and is not subject to the surgeon’s experience.