Comparing accuracy in guided endodontics: dynamic real-time navigation, static guides, and manual approaches for access cavity preparation - an in vitro study using 3D printed teeth

Objectives: To assess root canal localization accuracy using a dynamic approach, surgical guides and freehand technique in vitro. Materials and methods: Access cavities were prepared for 4 different 3D printed tooth types by 4 operators (n = 144). Deviations from the planning in angle and bur positioning were compared and operating time as well as tooth substance loss were evaluated (Kruskal-Wallis Test, ANOVA). Operating method, tooth type, and operator effects were analyzed (partial eta-squared statistic). Results: Angle deviation varied significantly between the operating methods (p < .0001): freehand (9.53 +/- 6.36 degrees), dynamic (2.82 +/- 1.8 degrees) and static navigation (1.12 +/- 0.85 degrees). The highest effect size was calculated for operating method (eta P-2=0.524), followed by tooth type (0.364), and operator (0.08). Regarding deviation of bur base and tip localization no significant difference was found between the methods. Operating method mainly influenced both parameters (eta P-2=0.471, 0.379) with minor effects of tooth type (0.157) and operator. Freehand technique caused most substance loss (p < .001), dynamic navigation least (p < .0001). Operating time was the shortest for freehand followed by static and dynamic navigation. Conclusions: Guided endodontic access may aid in precise root canal localization and save tooth structure.