Ex-vivo and in-vivo validation of a novel measuring protocol for guided endodontics

Objectives: To (1) validate the use of a post-operative intraoral scan (IOS) versus Cone Beam Computed Tomography (CBCT), gold standard, on its ability to measure the accuracy of guided endodontics, and (2) present clinical data on the accuracy of guided endodontics.Methods: Four models, including 10 extracted teeth each, were created. Forty guided access cavities were planned on dentin to simulate pulp canal obliteration (PCO). Two operators performed guided access cavities. A postoperative CBCT and IOS were acquired. The coronal, apical, and angular deviations were measured with CBCT and IOS. Clinical accuracy was measured using an IOS acquired immediately after drilling the access cavity with the aid of a guide. Data analysis was performed using multiway Anova and corrected for simultaneous hypothesis testing according to Tukey. P & LE; 0.05 was considered statistically significant. Descriptive statistics on the clinical accuracy of guided endodontics were performed.Results: Thirty-eight cavities were assessed with a mean length of 13.8 mm. No statistical difference between operators and methods was found for all parameters (P > 0.05). Thirty-three patients were treated with guided endodontics and measured using an IOS. Results show an average coronal, apical, and angular deviation of 0.2 mm, 0.45 mm, and 1.91 degrees respectively. The average length of the access cavities was 12.5 mm. Conclusions: An IOS can be used to measure the accuracy of guided endodontics.Clinical data showed high accuracy of guided endodontics with a mean apical deviation smaller than 0.5 mm and a mean angular deviation of less than 2 degrees. Clinical significance: The use of an IOS does not involve additional radiation exposure. A safety margin of at least 1 mm around the planned trajectory should be respected when planning the case to minimize the possibility of root perforation.