Effect of remineralizing agents on proteolytic activity and resin/caries-affected dentin bond longevity

Abstract

There is a common consensus that resin/dentin bond interface created with contemporary adhesive systems deteriorates overtime, being the optimization of this interface considered one of the most important challenges for restorative dentistry. In real clinical conditions, the adhesive monomers are not able to encapsulate the exposed collagen matrix, leaving totally or partially exposed collagen fibrils at the bottom of the hybrid layer, especially when the dentin is caries-affected. Thus, the lack of protective resin, the presence of water from dentinal fluid and the exposure of dentin proteases involving collagen fibrils, like MMPs and CTs, become factors associated to degradation of resin/dentin bond interface. A new approach aims to improve this interface with the use of remineralizing agents that replace intra and interfibrilar collagen spaces by apatite crystals, and restore the structural integrity of caries-affected dentin, inhibiting the action of proteolytic enzymes with their fossilization. This project will evaluate the action of agents with remineralizing activity in proteolytic activity and in longevity of resin/human dentin caries-affected bond interface. It will be used 189 caries-free third human molars, which will be distributed in three assays: 1 - assessment of proteolytic activity of caries-affected dentin after treatment with remineralizing agents; 2 - assessment of proteolytic activity of bond interface resin/dentin caries-affected after treatment with the same agents; and 3 - evaluation of hydrolytic degradation and micromorphology of resin/dentin caries-affected bond interface treated with remineralizing agents, at 24 hours and 6 months. The development of this project will contribute greatly to the knowledge of inhibitors of proteolytic activity in dentin, that may repair the mineral loss of the tissues affected by caries and, at the same time, facilitate the fossilization of enzymes, inhibiting them for a long-term and increasing the durability of resin/dentin bond. (AU)