Amalgam alternatives--micro-leakage evaluation of clinical procedures. Part I: direct composite/composite inlay/ceramic inlay.

This study investigated the degree of dye penetration with three different types of tooth-coloured restorations. Twenty-four intact extracted molars were collected. The teeth were immediately stored in water at room temperature. Class II cavity preparations were prepared and restored with three different types of tooth-coloured restorations: A, composite resin in the incremental technique; B, composite inlay technique; and C, ceramic inlay. Specimens were subjected to 700 cycles of thermal stress. They were than immersed in 2% basic fuchsin dye. The teeth were sectioned in three planes before being ranked as to the amount of dye penetration. The highest score obtained on three plano-parallel sections was adopted as the representative value. The three groups were compared using the Kruskal Wallis non-parametric test. Dye penetration was significantly lower at the enamel margins when using the composite inlay system and the incremental technique compared to the ceramic inlay technique. The restorations placed using the composite inlay technique showed less dye penetration than the incremental technique at the dentine margins (P < 0.017).