Avaliação Histomorfométrica do efeito de um Bioativo Amazônico sobre a Camada Híbrida da Dentina

Abstract

The adhesion of polymeric materials to dentin is still considered a big challenge because it is a complex histological substrate, predominantly tubular and intrinsically moist. Sclerosis and pathological processes such as caries, as well as the dentin demineralization, result in dentin properties changes. Among these transformations there is the activation of matrix metalloproteinases (MMPs) in the dentin matrix after etching. The solvents and monomers effects on the demineralized dentin have an important role in the whole concept of bonding. The use of disinfectant solutions has become an alternative to reduce these effects. Despite the great efficacy, the 2% chlorhexidine (CHX) can bring side effects. Thus, this research aims to morphometrically analyze the effect of copaiba oil emulsion 10% (COE) on the collagen of sound and carious dentin. In the analysis of the exposure of collagen fibers 80 specimens were fabricated. In the collagen fibers exposure analysis 80 specimens were fabricated from sound third molars that were immersed in test solutions for 3 months aging: G1- sound dentin (SD) + water, G2 - carious dentin (CD) + water, G3 - SD + 2% CHX, G4 - CD + CHX, G5 – SD + COE with preservative A (COE+PA), G6 - CD+COE+PA, G7 - SD + COE with preservative B (COE+PB), G8 - CD + COE+PB, G9 - SD + COE with preservative (COE+PC), G10 - CD + COE+PC. The specimens were histologically prepared, stained with Goldner's trichrome and analyzed. To analyze the examiner’s reproducibility the Pearson correlation test was used. To the data of thickness collagen layer was applied the non-parametric Kruskal-Wallis test (p <0.05). Increased frequency of exposed collagen was observed in G10 (CD+ COE+PC), followed by groups G6 (CD+COE+PA) and G5 (SD+COE+PA). The data showed no statistical difference between the groups G7 and G9, which had the thickest hybridized collagen, no difference when compared to G1 and G2, which showed less thickness. The G3, G4 and G8 groups showed no statistically significant difference between themselves and the other above. Qualitative analysis of histological samples for the study was taken by three pathologists simultaneously. Specimens treated with COE had the thickest exposed and hybridized collagen than the groups treated with CHX and water. Regarding the CD, the CHX group treated showed higher proportion of specimens with hybridized collagen. G7 showed 100% of specimens with hybridized collagen and better homogeneity of the hybrid layer.