[Marginal fit of ceramic and composite inlays in vitro]

Direct and indirect composite and ceramic inlays exhibit a space between inlay and tooth, which is filled with a luting composite resin. The aim of the present study was to evaluate the influence of the width of this space upon the quality of the marginal seal of the inlay system. The marginal quality of class II-inlays with small (0.2 mm) and large (0.4 mm) spaces was examined using quantitative SEM analysis and dye penetration. Regular class-II composite fillings served as controls. After thermal and mechanical loading the composite inlays with the wider composite layer showed more marginal gaps than both groups of ceramic inlays. The ceramic inlays did not show a significant deterioration of the margins. The least amount of dye penetration was observed in ceramic inlays with a wider composite layer at the interproximal cavity wall. Composite fillings showed more dye penetration than inlays.