Desenvolvimento e avaliação de um novo adesivo odontológico para remineralização biomimética de interfaces adesivas

Abstract

A recent alternative to promote restorative durability is biomimetic remineralization. It uses two phosphoprotein analogs from dentinogenesis and could be performed using a two-step self-etching adhesive containing bioactive calcium phosphates in the adhesive and a new biomimetic analogue (EDTF, ethylene diamine tetramethylene phosphonate) in the primer, acting as the two different types of analogues Already known. Thus, an experimental adhesive was prepared and pre-mixed with mono-calcium phosphate monohydrate and beta-phosphate tri-calcium in the bond. In addition, primers were developed according to the experimental design. A primer with no analogs and no particles in the bond (one negative control, CN), one containing the most used analogues in the literature trimetaphosphate (TMP) of sodium and polyacrylic acid (APA) (TMP / APA - positive control, CP), and others containing EDTF / TMP, EDTF / APA or EDTF alone were prepared. A group with only particles in the bond and without the analogs in the primer was also used. These adhesive systems were applied in artificially simulated carious dentin (DAC) and in healthy dentin of extracted human molars. After periods of 24h and 6 months of storage, they were evaluated by microtraining, nanoinfiltration and Micro-Raman spectroscopy of the interface (hybrid layer) and the underlying dentin. Microtraction data were analyzed statistically with two-way ANOVA and Tukey's test (α = 5%). In the microtraction of the hybrids, there was only statistical difference (p <0.05) in the EDTF / TMP groups, showing an increase in union strength after 6 months and in the EDTF / APA group, which had a decline. In DAC, there was a decrease in CN, EDTF / TMP and EDTF / APA groups (p <0.05). In the analysis of nanoinfiltration in DAC, the CN revealed the presence of cracks and degradation in the immediate dentin region, and in the adhesive layer after aging, which was not observed in the other groups. In Micro-Raman spectroscopy it was possible to observe the presence of more marked mineralization in the CP, EDTF, EDTF / TMP and only particles groups, but this was not observed in the CN and EDTF / APA groups. It is concluded that the best results for adhesion and remineralization of dentin affected by caries are obtained with the use of traditional analogues (TMP / APA) or with EDTF alone and associated with TMP, without affecting the adhesion to the healthy dentin.