Effect of Chairside CAD/CAM Restoration Type on Marginal Fit Accuracy: A Comparison of Crown, Inlay and Onlay Restorations

Chairside CAD/CAM is a convenient approach for fabricating dental restorations. However, the effect of CAD/CAM restoration type on marginal fit accuracy has not been fully investigated. This study evaluated of the marginal fit accuracy of 3 chairside CAD/CAM restoration types (crown, inlay and onlay) using CEREC Bluecam (BC) and CEREC Omnicam (OC) scanners. Three artificial maxillary first molars received crown, inlay and onlay preparations. A total of 10 CAD/CAM ceramic restorations were produced for each tooth by each intraoral scanner. The marginal gap was measured along the preparation margin. For the BC, all the restorations had similar marginal gaps (crowns = 113.9 mu m; inlays = 120.9 mu m; onlays = 132.5 mu m) (p = 0.20), while for the OC, the crowns (72.2 mu m) and the inlays (74.9 mu m) exhibited better marginal fit than the onlays (96.4 mu m) (p = 0.003). For every restoration type, the OC provided a superior outcome compared with the BC. Therefore, the restoration type influenced the marginal gap, where the crowns tended to have the least marginal gap while the onlays had the greatest marginal gap. The newer scanner (OC) of the same manufacturer was more accurate than the older scanner (BC).