Clinical evaluation of all-ceramic crowns fabricated from intraoral digital impressions based on the principle of active wavefront sampling

Abstract: Objectives: The aim of the present study was to compare the fit of all-ceramic crowns fabricated from intraoral digital impressions with the fit of all-ceramic crowns fabricated from silicone impressions. Methods: Twenty patients agreed to take part in the study to receive two Lava™ crowns each for the same preparation. One crown was fabricated from intraoral scans using the Lava™ Chairside Oral Scanner (Lava C.O.S.), and the other crown from a two-step silicone impression. Prior to cementation the fit of both crowns was clinically evaluated by two calibrated and blinded examiners; the marginal fit was also scored from replicas. Data from the replica scores were analysed by Anderson–Darling test, Levene''s test and Mann–Whitney test. All tests were performed with α-level of 0.05. Results: Median marginal gap in the conventional impression group was 71μm (Q1:45μm; Q3:98μm), and in the digital impression group 49μm (Q1:32μm; Q3:65μm). Mann–Whitney test revealed a significant difference between the groups (p <0.05). No differences were found regarding the occlusion, and there was a trend for better interproximal fit for the digitally fabricated crowns. Conclusions: [1.] Crowns from intraoral scans revealed significantly better marginal fit than crowns from silicone impressions. [2.] Marginal discrepancies in both groups were within the limits of clinical acceptability. [3.] Crowns from intraoral scans tended to show better interproximal contact area quality. [4.] Crowns from both groups performed equally well with regard to occlusion. [Copyright &y& Elsevier]