Evaluation of the adhesive interface obtained in composite restorations performed with a universal adhesive system used with and without acid etching.

摘要

Objective The purpose of this research was to study the tooth-restoration adhesive interface, using a universal adhesive system (Single Bond Universal, 3M/ESPE, Germany), with the techniques of etching and self-etching using scanning electron microscopy. Material and methods Class V cavities were prepared in buccal and palatine/lingual surface, in human teeth. Etching with 37%H3PO4 was performed in the buccal cavity, with no etching being performed in the palatine or lingual cavity. The samples were placed in an oven at 37 °C and 100% humidity for 48 hours, simulating the oral environment. The samples were cut perpendicularly through the restoration and prepared to be observed by scanning electron microscopy, in order to evaluate the adhesive interface in relation to the presence of breaches and the formation of resin tags. Results Images were observed with a gradual increase to 2000×. Microstructural differences were observed in the penetration of the adhesive but with no formation of breaches in the adhesive interface. Conclusions An unbreached interface is obtained when using both techniques. In enamel, less penetration was present in the crystal structure of the adhesive with the self-etching technique. While in dentin, with the same technique, a less thick hybrid layer and shorter resin tags were observed.