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, twolayer 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 µm, 95.4 96.2 µm, and 104.6 78.1 µm) compared to milled restorations (58.4 93 µm, 145.9 85.8 µm, and 138.6 65.7 µm).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.