Introduction: The precision of impressions has a significant impact on the marginal adaptation of fixed restorations. Fit is the most significant factor influencing the restoration's durability, retention, and periodontal health.
Aim of study: to compare the marginal fit of CAD/CAM zirconia crowns manufactured using two distinct digital impression techniques.
Materials and methods: A typodont tooth in the upper premolar region was prepared to receive a complete ceramic crown. A direct scan of the prepared tooth was used to create twenty 3D-printed resin impressions. The master dies were divided into two groups at random (n = 10 per group). Group I: scanning the dies digitally. Group II: digital digitization of the scannable impressions of scannable silicone. Using cone beam CT, the marginal gap and marginal discrepancy were evaluated.
Results: Group I had a marginal gap of (119.5 ± 27.0) µm, which was substantially smaller than Group II's (144.8 ± 25.23) µm, and a marginal discrepancy of (107.5 ± 36.36) µm, which was smaller than Group II's (154.3 ± 49.53) µm.
Conclusion: Although direct digital scanning was superior to indirect digital scanning in terms of marginal fit, all tested techniques yielded clinically acceptable fit values.
Keywords: Marginal fit, CAD/CAM, digital impression.
Running title: Marginal fit of zirconia crowns fabricated by direct and indirect digital scanning.