Invisible supragingival crown margins: an in vitro study.

A method of improving the esthetics and seal of porcelain crown margins using composite resin is described. The procedure includes a circumferential shoulder-type preparation located entirely in enamel. To provide adequate space for a thin layer of composite resin to blend gradually into both tooth enamel and porcelain surfaces, the cervical enamel as well as the opposing porcelain butt joint are subsequently beveled. In this study, microleakage analysis and SEM evaluation of the marginal area indicate that the marginal design described can predictably produce an optimal esthetic appearance and marginal seal, contour, and integrity with supragingival ceramic restorations.