Objectives: The purpose of this study was to compare the marginal fit of the anterior single restorations made using the digident CAD/CAM zirconia ceramic crowns with metal-ceramic restorations and to obtain more accurate information by using a large enough sample size and by making sufficient measurements per specimen. Methods: The crowns were made from one extracted maxillary central incisor prepared with a 1mm shoulder margin and 6° taper walls by milling machine. The in vitro marginal discrepancies of the digident CAD/CAM zirconia ceramic crowns and control groups(metal ceramic crowns) were evaluated and compared. 20 crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Results: The means and standard deviations of the marginal fit were 88±10µm for the control group, 92±4 µm for the Digident CAD/CAM zirconia ceramic crowns. In the the t-test of the marginal discrepancies between Digident CAD/CAM zirconia ceramic crowns and metal-ceramic crowns, Significant differences were not found between groups (P=0.193>.05).
Conclusion:Within the limitations of this in vitro study, the following conclusions were drawn: 1. The digident CAD/CAM zirconia ceramic crowns showed slightly larger marginal gap discrepancy than the control but marginal gap between digident CAD/CAM zirconia ceramic crowns and metal ceramic crowns did not showed significant difference ( P>.05). 2. The digident CAD/CAM zirconia ceramic crowns and metal ceramic crowns showed clinically acceptable marginal discrepancy(88±10µm for metal-ceramic crowns, 92±4µm for digident CAD/CAM zirconia ceramic crowns.)