Figure 4.

Schematic sectioned view of reference points for evaluation (a) and measurement images (b) the marginal fit in this study. Marginal internal gap (MIG); the perpendicular measurement from the internal surface of the coping to the axial wall of the abutment at the end of the margin, Absolute marginal discrepancy (AMD); the angular combination of the marginal gap and the extension error which is measured from the margin of the coping to the cavosurface angle of the abutment. In this study, we measured the AMD as the two-dimensional vertical marginal gap. (5 points × 4 areas × 12 specimens × 3 groups, total 720 points).