Quantitative assessment of contour

The degree of concavity was quantitatively evaluated by measuring the area and depth of the concavity using 3D image reconstruction. A stone jig with the impression of the distal surface of the artificial tooth was used as a positioner for the horizontal placement of the restored teeth. Quantitative assessment of contour was done using the Medit scanner superimposing method and ExoCAD software. A Hypertext Markup Language-based program was developed to quantify the concavity of the proximal contours. The greatest distance from the concave surface to be orthogonal to the plane was defined as the depth of the concavity.

One-way ANOVA test was used to compare the mean M-D diameter (in mm) in occlusal and middle third as well as proximal contact area (in mm) between the three groups.

Chi-square test was used to compare the proximal contact area using the passage of Unifloss and buccolingual and occluso-cervical morphology between the three groups. The level of significance was set at P < 0.05.