Resumen
Abstract PURPOSE: To assess in vitro the hydrolytic stability of adhesive systems in Class V composite restorations bonded to enamel and dentin. METHODS: 16 groups of Class V cavities restored with different adhesive systems and challenged with thermal and mechanical loading under the simulation of dentin fluid were evaluated after an 18-month period of water storage at 37 degrees C. The marginal adaptation of these restorations was quantified by evaluation of gold-coated epoxy replicas with scanning electron microscopy at x200 magnification. RESULTS: The percentages of 'continuous margin' after 18 months of water storage with respect to the total marginal length ranged from 62.9 (5.4) porciento to 18.5 (3.2) porciento with significant differences observed among the groups Bonferroni test P < 0.05). The range in enamel was from 71.8 (14.2) porciento to 8.9 (6.4) porciento and in dentin from 94.3 (5.1) porciento to 0.0 (0.0) porciento. Marginal adaptation of all the materials tested was affected by water storage, either in enamel, in dentin, or both. None of the restorative systems tested exhibited hydrolytically stable marginal adaptation. (AU)
