Evaluation of Marginal and Internal Adaptation of Endocrowns Fabricated from Three Different CAD/CAM Materials

Objectives: This in vitro study aimed to compare the internal and marginal discrepancies of endocrowns fabricated from different ceramics before and after adjustment. Methods and Materials: Thirty-six endocrowns were fabricated from lithium disilicate (IPS e-max CAD), zirconia-reinforced lithium silicate (Suprinity), and polymer-infiltrated ceramic network (Enamic) using a CEREC intraoral scanner and milling unit. A reference point matching scan protocol was used to measure the endocrowns fit. The mixed ANOVA was used to analyze the data, and alpha=0.5 was considered as the significance level. Results: There was no significant interaction between the fabrication materials and adjustment (P>0.05). Type of the materials did not change discrepancies at cavosurface, line angle, cavity wall, and pulpal floor (P>0.05). On the contrary, adjustment significantly decreased the discrepancies at all four sites (P<0.001). There were significant differences between every two sites before adjustment (P<0.001). After adjustment, except for cavosurface and cavity wall (P=0.058), the differences between other sites remained significant (P<0.001). Conclusions: IPS e-max CAD, Suprinity, and Enamic endocrowns were not significantly different regarding internal and marginal discrepancies. However, it is suggested that these materials be adjusted to fall in a clinically acceptable range to minimize the risk of caries and periodontal disease.