Evaluating the Accuracy of Dental Restorations Manufactured by Two CAD/CAM Milling Systems and Their Prototypes Fabricated by 3D Printing Methods: An In Vitro Study.

This article focuses on an in vitro evaluation of the marginal accuracy of all-ceramic dental onlay restorations fabricated using two subtractive manufacturing (SM) CAD/CAM milling systems and two additive manufacturing (AM) 3D printing methods: stereolithography apparatus (SLA) and digital light processing (DLP). Ten typodont first molars were prepared and scanned with two different scanners, and virtual onlay restorations were designed and produced via the three fabrication methods. Marginal gaps measured at six reference points ranged from 59 to 84 μm across all groups, with no statistically significant differences found between subtractive and additive methods; all gaps were within clinically acceptable limits (generally considered below 120 μm). The study concludes that both subtractive milling and additive 3D printing techniques, using the evaluated systems, are suitable for producing onlay restorations with acceptable marginal fit.