Influence of deproteinization and of wet on the dentinal substratum on microleakage in composite restorations

Abstract

The purpose of this study was to verify the influence of the deproteinization and condition dentinal substratum (wet or dry) in the microleakage in resin composite restorations. Eighty preparations class V, prepared in forty human third molars (tooth bank of the FOUPF), with gingival margin in dentin were randomly assigned into four groups: G1 (control - adhesive (Prime & Bond 2.1, Dentsply) applied according to the manufacturer’s directions; G2 - same procedures of G1, however adhesive applied to the dry dentin; G3 - after the demineralization the sodium hypochlorite was applied (NaOCl 10%, 60s) for collagen removal and the adhesive applied to the wet dentin; G4 - same procedures of G3, however the adhesive applied to the dry dentin. After being restored, the specimens were thermocycled, isolated, color immersed, acrylic resin included and sectioned. For the sections analysis, an optical microscopic and tabulated scores were used. The scores were submitted to statistical analysis (Kruskal Wallis/1%; Ho = 0,69%), where G3 and G4 presented statistically significant differences among themselves. The other groups did not present statistically significant differences. In the experimental conditions, it was possible to conclude that, the collagen does not have any influence on the marginal leakage. A significantly lower rate of microleakage was found after collagen removal to the dry dentinal substratum. Key words: Desproteinization. Collagen. Dentin. Adhesive system. Microleakage.