COMPARATIVE STUDY OF MARGINAL GAP IN CAD-CAM VERSUS PREFABRICATED SIZE-MATCHING RESTORATIONS

Abstract

The purpose of this study was to determine the gap formation in CAD/CAM and SONICsys and to compare the gap formation in both systems. A total of twenty selected freshly human sound premolars of similar size and shape were chosen and class II cavities were prepared with standardized dimensions by the help of SONICsys tips size 3.

The prepared teeth were divided randomly into two groups according to the restoration technique Jhere in group 1, ten of the prepared proximal cavities were restored using CAD/CAM system and in group 2, the other ten were restored using ready-made ceramic inserts of matching size to the preparing tip of SONICsys system. Cerec inlays were milled after adjustment of the design using projection and cut windows during data acquisition and imaging. In each group, restorations were cemented with the recommended adhesive cementation system. The ceramic restorations as well as the prepared cavities were further prepared for adhesive cementation. After cementation of the inlays according to the manufacturer's instruction, marginal gaps examination were done using S.E.M in seven different points: labio-occlusal, mid-labial, labio-cervical, mid-cervical, linguo-cervical, mid-lingual and linguo-occlusal corresponding to points a, b, c, d, e, f and g respectively.

S.E.M examination showed that the gap formed in SONICsys was much smaller than that of CAD/CAM. The lowest value recorded in CAD/CAM system was in mid-cervical whereas the highest value recorded was at occluso-labial points.