In vitro caries related to marginal leakage around composite resin restorations

The histology of caries-like lesions around composite resin restorations with and without marginal leakage has been studied. The lesions were generated from bacterial plaque growing in an in vitro system. Marginal leakage was prevented by an acid etch technique. Ground sections of the experimental teeth were studied by polarized light and microradiography. The caries lesions penetrated along conventional class V restorations with marginal leakage while restorations bonded to an acid etched enamel surface totally prevented this ingrowth.