Evaluatjon of the adhesiveness in enamel conventional adhesive systems and self-etching

Abstract

Until the beginning of the ni- neties, to get adhesion in enamel, it was necessary previous condi- tioning. Recently new bond syste- ms known as self-etching primers appeared in the market and, in clinical procedures they spare the previous acid conditioning. The doubt that these new mate- rials might produce adhesion in enamel motivated this research, and thus we used three groups of twenty bovine incisive teeth with the enamel surface leveled with a diamond bur. These teeth were in- cluded in self-curing acrylic resin, in a PVC cylinder with 25mm in diameter and 10mm-height. The groups were treated in different ways, according to manufacturers' instructions [Clearfil SE Bond- Kuraray-(CSE-B), Etch & Prime 3.0-Degussa - (E&P 3.0), Scotch- bond Multipurpose-3M - (SBMP)]. In the surface of each specimen a cylinder of composite resin was fi- xed (Herculite XRV-Kerr) having 5mm in diameter and 3mm in height. The specimens were sub- mitted to shearing strength, with a chisel applied in the interface, in a universal test machine. The results, after application of statis- tical tests One Way ANOVAusing the software Origin Microcal 4.0, demonstrated significant diffe- rences among each other, when p < 0,0001. For group 1 (CSE-B): 15,77MPa. For group 2 (SBMP): 13,06MPa. For group 3 (E&P 3.0): 4,51MPa. The results demonstra- ted that adhesion in enamel of the system E&P 3.0 is defective; however, in relation to the system CSE-B, the values indicate the op- posite, because the adhesiveness numbers were superior to the sys- tem SBMP. Key uiords: Self-etching primers, shear strength, enamel.