Influence of human and bovine dentin substrate in the cytotoxicity of materials used for cementation of indirect restorations

Abstract

The choice of a biocompatible luting agent is critical to the clinical success of indirect restorations. Thus, in order to validate the use of these materials so that they do not cause damage to the pulp-dentin complex, the first step is to analyze their cytotoxicity in vitro. In order to mimic the clinical conditions, the use of a set called the artificial pulp chamber (APC) has been shown to be an effective experimental model to evaluate new materials and their application techniques, in order to simulate the presence of the dental substrate on which the material is applied. With the purpose of using bovine dentin as a substitute for human dentin, studies are necessary showing its similarity regarding the response to the evaluation of trandentinal cytotoxicity of dental materials. Therefore, the main objective of this project is to analyze the influence of human and bovine dentin substrates on the transdentinary cytotoxicity of materials used for cementation of indirect restorations on pulp cells and to compare the possible transdentinary cytotoxic effect of these materials. To do this, the CPAs will be made using human and bovine dentin discs, presenting 0.4 mm thickness, in order to mimic the performance of a cavity preparation whose dentine remnant thickness is very close to the pulp tissue. Next, the CPAs will be adapted into 24-compartment plates containing culture medium and the materials used for cementation of indirect restorations will be applied to the occlusal surface of the discs. After 24 h of incubation, the culture medium containing the components released from dental materials that diffuse through the dentin disc (extract) will be applied on odontoblast-like MDPC-23 cells and on human pulp cells (HDPCs), in order to evaluate the influence of these materials on viability, morphology, adhesion and cell spread, as well as on the phenotypic expression of these cells. For this study, a resin-modified glass ionomer cement, a resin cement using etch-and-rinse technique, and a self-etching resin cement will be tested. As a positive control, etch-and-rinse adhesive system will be used, and as a negative control, no treatment will be used. The numerical data will be submitted to specific statistical analysis. (AU)