ABSTRACT
PURPOSE: To evaluate the effect of cavity tapering on marginal and internal adaptation of endocrowns fabricated from two different ceramic materials. MATERIALS AND METHODS: Two mandibular molar model teeth were prepared with two different cavity tapers (5 and 10 degrees). A total of 40 endocrowns (four groups of 10 each) were milled using lithium disilicate and zirconia-reinforced lithium silicate ceramics for each cavity taper. The marginal and internal adaptation of endocrowns were measured by a stereomicroscope (×30) at 18 different points. The data were statistically analyzed using independent t test (P < .05). RESULTS: A statistically significant difference was shown among the tested groups at 10 degrees of taper (P < .001). At 5 degrees of taper, the difference was insignificant. The greatest internal gap was observed at the pulpal floor in all tested groups. CONCLUSION: All materials had clinically acceptable internal and marginal gaps; however, lithium disilicate ceramic had significantly better adaptation at 10 degrees of taper. Int J Prosthodont 2023;36:189-193. doi: 10.11607/ijp.6877.