Avaliação do efeito da escovação e polimento na liberação de Bisfenol A em resinas compostas fotopolimerizáveis

Abstract

Dentistry has been undergoing constant changes in all parameters, whether in techniques or materials. The evolution of resin composites had a great highlight in the 50's, when it was possible to show to the world the enamel acid etching technique, improving the adhesion to the dental structure. In 1956, Bis-GMA was introduced, which improved the composite resins' properties, widening their indication. The evolutions of these materials have gone much further, changes promoted in the composition, mainly regarding the size and distribution of the load particles, have improved some properties of these materials. Today, in the dental products market, several types of resins, which differ in their composition, have emerged during this evolutionary process, each one having its indications and limitations. Composite resins are composed of a methacrylate-based resin matrix, a system of photoinitiators, and load particles treated with a silane bonding agent. Among this composite resin constitution, bisphenol A-Glycidyl methacrylate (Bis-GMA) is used because it has low volume shrinkage, good mechanical properties, low volatility and diffusion in tissues. These qualities make Bis-GMA one of the most widely used monomers in the production of dental composites. The overall objective of this study is to evaluate the effect of simulated brushing and polishing on the release of the Bis-GMA component present in light-cured composite resins used in dentistr. The resins Z350, Empress Direct, Forma, Natural Flow and Vittra were used. It was possible to identify that the release of Bisphenol A is associated with the removal of surface layers of resins. and the 3M and Empress Direct resins showed a greater release of BPA with the brushing time. Forma and Vittra resins decreased BPA release with longer brushing time. The DFL resin showed a difference in the release behavior of the different resins, showing no difference with shorter or longer brushing time. Bpa release related to finishing and polishing was higher for all resins in the finishing process than polishing.