Objective: The aim of this study was to evaluate the influence of cone-beam computed tomography (CBCT) resolution, 3D printing resolution, and drilling depth on drilling accuracy in guided endodontic access.
Methods: Fifty-six printed canines were designed, fabricated, and mounted in maxillary arch models. Preoperative CBCT and 3D surface scan were matched and used to design a surgical guide with different planning parameters: 1) reference (high-resolution CBCT and 3D printing, shallow drilling), 2) low-resolution CBCT, 3) low-resolution 3D printing and 4) deep drilling (high-resolution CBCT and 3D printing, deep drilling). Guided access into the printed canines was performed in a simulated clinical setting. A postoperative CBCT was matched with the planning data in order to determine the angular and linear (total, mesiodistal, buccolingual and depth) deviation between the planned and performed cavities. Mann-Whitney test was used to analyse differences between the reference group and each test group.
Results: Angular, total linear and buccolingual deviations were significantly higher in the low-resolution CBCT group than in the reference group (median (Q1; Q3): 3.10° (2.30°; 5.00°) and 2.0° (0.78°; 2.60°) (P<0.01), 1.41 mm (1.21 mm; 1.70 mm) and 1.06 mm (0.69 mm; 1.31 mm) (P<0.05) and 0.77 mm (0.41 mm; 1.12 mm) and 0.41 mm (0.21 mm; 0.61 mm) (P<0.05), respectively). Depth deviation was significantly higher in the low-resolution 3D printing group than in the reference group (median (Q1; Q3): 0.90 mm (0.52 mm; 1.08 mm) and 0.45 mm (0.25 mm; 0.62 mm) (P<0.01), respectively). No other significant differences between the groups were noted.
Conclusion: Higher CBCT resolution resulted in lower angular and total linear deviation during guided endodontic access. Higher 3D printing resolution yielded lower vertical linear deviation. (EEJ-2024-05-086)