Micro-CT analysis of in-office computer-aided designed/computer-aided manufactured dental restorations

Abstract Purpose: The current study evaluated two different materials, using micro-CT to compare the marginal gap of feldspathic ceramic (V) and resin nano-ceramic (L) crowns obtained by two different computer-aided design/computer-aided manufacturing (CAD/CAM) systems, CEREC CAD/CAM system and E4D Technologies. Methods: A human lower left first premolar was mounted on a typodont model and prepared for an all-ceramic crown. Two groups (n = 5) were divided based on the system for obtaining the crowns and the material used for it (V and L). Micro-CT images were obtained for marginal gap measurements of each crown, and the data were statistically analysed by one-way analysis of variance followed by Tukey’s post hoc test for pairwise comparisons (α¼ 0.05). Results: There were no statistically significant differences between marginal gap of groups V and L (p = 0.473). The mean and standard deviation for the vertical misfit was V = 62.6 (65.2) and L = 66.5 (59.0). For the horizontal misfit, the values were divided into three groups: underextension (L = 20.8%) and (V = 54.6%), equally extended (L = 16.9%) and (V = 36.9%) and overextension (L = 62.3%) and (V = 8.5%). Conclusion: The results revealed no difference in the marginal fit of crowns produced by different materials and different chairside CAD/CAM systems. Both are considered clinically acceptable according to all cited classifications.