*2.7. Marginal Misfit*

The coping misfit was assessed in micrometer (μm). Misfit was analyzed with Bruker micro CT (Skyscan 1173 high-energy spiral scan micro-CT; Skyscan NV, Kontich, Belgium) to detect micro gaps at selected points. The coping samples were mounted and positioned inside the specimen chamber and the parameters included 130 kV of source energy at 60 μA at 300 ms of exposure time. To create a good image, a brass filter of 0.25 mm with a 0.2◦ rotation step for a 360◦ angle and 4-frame average was employed. Post scanning, reconstruction of 3D images was performed using N-Recon® software (program version 1.6.1.3, Bruker Skyscan, Kontich, Belgium). During this process, parameter adjustments were performed to enhance image quality. Reconstructed images were loaded in the Dataviewer® Software (Bruker Skyscan, Kontich, Belgium) to determine image quality and perform image misfit assessments. The measurements were preformed between the marginal surface of the coping and the prepared marginal surface of replicas of master die (Dental stone).

All assessed recordings for surface roughness and marginal misfit were logged in an Excel sheet and mean and standard deviations were evaluated. Data were analyzed using Analysis of variance (ANOVA) and Tukey Kramer multiple comparisons test. Correlation between specimen roughness and misfit was assessed using Pearson correlation. A *p* value of <0.05 was considered statistically significant among groups.
