Analysis of bonding interface between self-adhesive resin cement to in vitro eroded dentin

Abstract

The purpose of this study will be evaluate the bonding interface between self-adhesive resin cement to in vitro eroded dentin. Sixty-four third molars will be used and divided into two groups: group 1 (standard dentin) and group 2 (eroded dentin). The in-vitro erosion will be created following a demineralization protocol, in which the specimens of group 2 will be immersed in HCl-pepsin solutions during 5 minutes per cycle, and in trypsin solution, 10 minutes per cycle, totaling 6 immersions per day on both solutions; and manually brushed, 2 times per day during 6 days. Both groups will be submitted to four dentin surface treatments: control group (without any treatment), 25%polyacrylic acid, 2% chlorhexidine and 0,1M EDTA pH 7.4 (n=8). TPH resin-based composite blocks will be bonded with RelyX U200 self-adhesive resin cement on the pretreated dentin surfaces. The samples will be submitted to microtensile bonding test to evaluate the bonding strength between self-adhesive resin cement to dentine, 24 hours and 1 year after the bonding procedure. The fractured samples will be evaluated in Scanning Electron Microscopy (SEM), to classify the fracture pattern of these interfaces. Finally, two specimens of each group will be evaluating by laser confocal microscopy, with the purpose to analyze qualitatively the dentin/cement interface. Data of microtensile bonding strength and dentin/cement interface quality will be submitted to statistical tests. (p=0.05). (AU)