Accuracy of Dental Restorations Fabricated Using Milling vs 3D-Printed Molds: A Pilot Study

Purpose: To compare the accuracy of 12 different dental restorations fabricated with milling or 3D-printed molds and robotically controlled casting. Materials and Methods: Twelve dental restorations (11 inlays and onlays and 1 crown) were made per restoration type, one per each of the 12 different teeth models (total of 24 restorations). On each tooth preparation, two restorations were manufactured using different CAD/ CAM techniques: (1) milling and (2) robotically controlled casting and 3D-printed molds. In addition, two-layer restorations were manufactured with 3D-printed molds. The marginal and internal gaps were evaluated at 120 points per restoration based on micro-CT 3D imaging. Internal gaps were evaluated using a replica technique with silicone. Results: Median values (interquartile ranges) for marginal gaps, middle internal gaps, and central internal gaps were significantly lower for 3D-printed mold restorations (44.3 [65.4] mu m, 95.4 [96.2] mu m, and 104.6 [78.1] mu m) compared to milled restorations (58.4 [93] mu m, 145.9 [85.8] mu m, and 138.6 [65.7] mu m). Internal gaps in the 3D-printed mold group were 6% to 51% smaller than in the milled group. Conclusions: The accuracy of restorations fabricated with 3D-printed molds may be preferable compared to milled restorations, except in the case of crown restoration. However, additional studies with a larger number of samples and different types of restorations are needed to confirm the results.