Avaliação da composição química, do desafio bacteriano, do acabamento/polimento e de protocolos de cimentação de diferentes materiais restauradores

Abstract

The general objective of this study was to investigate the chemical composition, finishing and polishing and luting protocols of different restorative materials. This study was divided into 4 chapters, according to the specific objectives: chapter 1) to evaluate how the addition of thiourethane influences the composition of the sol-gel composition and network structure of methacrylate-based materials; chapter 2) to evaluate the effect of bacterial challenge on the bond strength of composite resins repaired with silane modified with thiourethane; chapter 3) to evaluate the effects of oxygen inhibition and finishing/polishing procedures on the surface of conventional and bulk-fill composite resins; chapter 4) to evaluate luting protocols and the time to prosthetic preparation, in the bond strength and failure modes of fiber post to the root dentin of bovine incisors. The experimental methods used were degree of conversion, water sorption and solubility, dynamic mechanical analysis, extraction methods, micro-shear bond strength, color stability, opacity, micro push-out bond strength and optical microscopy. After statistical analysis of the data, it was concluded that the addition of thiouretane in methacrylates affected the composition in the sol-gel synthesis method in cross-link networks, which presented to be more homogeneous, with a lower amount of leached potentially toxic; after bacterial challenge, the use of TU silanes was able to maintain the bond strength of repaired interfaces of composites; post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee; both time to prosthetic preparation and luting protocol influenced the bond strength of the fiber post to the root dentin with combined effect; no cohesive failures were observed, and two adhesive failures in the interface between the post and root dentin were found.