الفهرس 
Classification by processing methodOnly 14 pages are availabe for public view
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Abstract
Pressed lithium disilicate, wax pattern, 3D printing, CAD/CAM. Purpose: This study was performed to evaluate the effect of different methods of fabrication of wax pattern on the marginal adaptation of heat pressed lithium disilicate crown restorations. Materials and methods: Three techniques were used for wax pattern fabrication,the first group was 3D printed, the second group was subtractive and the third was conventional technique. 10 samples were fabricated using each technique. USB Digital microscope with a built-in camera was used to capture the photos of the margins and a digital image analysis system was used to measure and qualitatively evaluate the gap width by selecting 8 eqidistant points along the margin and measuring the gap at each point. Results: F-test (ANOVA) was used to compare between more than two groups, and Post Hoc test (LSD) for pairwise comparisons.The overall mean marginal gap for the three groups (3D,subtractive and conventional) was (40.33 ± 0.77), (42.18 ± 1.44) and (43.13 ± 1.15) respectively. Post Hoc Test (LSD) revealed a significant difference between 3D and subtractive group (p=0.001) and it revealed a highly significant difference between 3D and conventional group (p <0.001).