Accuracy of Dynamic Navigation vs. Freehand Endodontic Access Cavity Preparation in 3-Dimensionally Printed Teeth with Severe Pulp Canal Calcification

Background: Pulp canal calcification (PCC) poses a challenge for endodontic treatment, as it obscures the canal and increases the risk of complications. This study aimed to evaluate the accuracy of endodontic access cavity preparation using dynamic navigation (DN) and to compare it with the freehand (FH) technique in teeth with severe PCC. Materials and Methods: Sixty 3D printed maxillary central incisors with simulated severe PCC were divided into two groups and accessed either with a DN system or by the conventional FH technique. Accuracy was evaluated by comparing planned and performed access cavity trajectories on preoperative and postoperative CBCT scans. Preparation time and procedural errors were recorded. Normality was assessed with the Shapiro–Wilk test. The Mann–Whitney U test was used to compare continuous variables. The significance level was set at 0.05. Results: The DN group showed significantly lower apical point 3D deviation (1.25 vs. 1.96 mm, p = 0.001), apical point depth deviation (0.43 vs. 0.88 mm, p < 0.001), and angular deflection (1.93 vs. 5.71 degrees, p < 0.001) than the FH group. The DN group had fewer procedural errors. The endodontic access entry point deviation was comparable between both techniques (p = 0.395). The preparation time was significantly higher in the DN group (204 vs. 108.5 s, p < 0.001). Conclusions: DN significantly improves the accuracy of access cavity preparation in calcified canals compared to the FH approach, reducing the risk of complications. Therefore, DN can be a valuable tool for managing challenging endodontic cases. As guided endodontic access preparation can be more time-consuming, extended treatment appointments may be required.