Avaliação por microtração da resistência de sistemas adesivos na dentina sadia e afetada por cárie em dentes humanos

Abstract

The aim of this experimental study was to evaluate by microtensile, the strength of two adhesive systems in dentin and sound dentin affected by caries in human teeth. Twenty human teeth were used for the study, which ten of them were teeth with healthy dentin, and the other ten teeth were affected by caries. Randomly, these teeth were divided into four groups, two groups of healthy dentin and two groups for each affected dentin adhesive system selected for the research. The teeth were standardized by cavity preparation and they were restored with adhesive system total conditioning Ambar (FGM, Brazil) with the composite resin Opalis (FGM, Brazil) groups (G1-sound dentin, G2-affected dentin) and the system self-etch adhesives Silorane Filtek (3M ESPE, USA) with a composite resin Filtek P90 (3M ESPE, USA), groups (G3- sound dentin, G4-affected dentin). The teeth were recovered and stored in distilled water at 37 °C for one week. After this period, the samples were sectioned vertically obtaining specimens with cross-sectional area of approximately 1.0 mm2, which were pulled at a velocity of 1.0 mm/min in a universal testing machine. Bond strength on the test method for microtensile reveals that the highest average values are found for the adhesive system Ambar (FGM, Brazil) compared to Silorane Filtek (3M ESPE, USA). In the system Ambar (FGM, Brazil) there is no difference between the results of bond strength to healthy dentin and dentin affected by caries. However, the adhesive system Silorane Filtek (3M ESPE, USA) has superior bond strength values for sound dentin when compared to the dentin affected by caries. The types of fractures observed in optical microscope don’t match accurately when observed in scanning electron microscopy. The analyzed type of fracture usually presented by specimens in the SEM was mixed.