Elalem, Inas A.Ibraheem, Rabab M.Hamdy, Ahmed M.2020-09-052020-09-052019-072369-4475http://repository.msa.edu.eg/xmlui/handle/123456789/3746Purpose: The aim of this study was to evaluate clinically the marginal integrity, and internal fit of endodontically treated molar teeth restored with endocrown restorations with two different preparation designs. Materials and Methods: Seventeen patients had a twenty endocrown restorations which were constructed of lithium disilicate (IPS E.max press ceramic). The endocrown restorations were randomly and equally divided into two groups regarding the marginal preparation designs; group 1: had a butt joint preparation and group 2: had a circumferential preparation with deep chamfer finish line. Evaluation of the marginal integrity and the internal fit were performed using silicon replica technique, each replica was sectioned into four segments and each segment had five reference points to be measured using digital microscope at 35X magnification. The data were analyzed using Two-way ANOVA and Post-hoc tests. Results: The marginal gaps of both groups were within the clinical acceptable range, but group 1 (73.49±5.29µm) was statistically significantly higher than group 2 (59.81±3.42 µm), meanwhile there was no significant difference regarding the internal fit of both groups as group 1(83.05±11.72 µm) had slightly higher mean value than group 2 (80.29±10.59 µm). Conclusion: Endocrown restorations with different preparation designs showed a clinical acceptable range of marginal and internal fit.en-USInternal Fit.Marginal IntegrityEndocrown RestorationsMarginal Preparation DesignsArticle