Este trabalho teve como objetivo avaliar os efeitos do pré-tratamento dentinário na resistência adesiva de um cimento de ionômero de vidro resina modificado, ante o teste de cisalhamento. Foram utilizados quarenta incisivos bovinos, armazenados em freezer. As superfícies dentárias foram desgastadas até exposição da dentina; e os dentes, divididos em quatro grupos: I - controle, com aplicação do primer previamente a inserção do cimento, de acordo com as instruções do fabricante; e os demais receberam os seguintes tratamentos antes da aplicação do primer e cimento: II - ácido poliacrílico; III - ácido maléico; IV - laser. Os corpos-de-prova foram mantidos em água destilada a 37ºC por 24 horas até serem submetidos aos esforços de cisalhamento em máquina Instron. Baseado na análise de variância e no teste de Duncan, conclui-se que os pré-tratamentos empregados propiciaram efeitos diferentes e estatisticamente significantes; o grupo controle e o ácido

This study had as objective to evaluate the effects of the pretreatment of dentin in the bond strength of a resin-modified glass ionomer before a shear bond strength test. Forty bovine's incisors, stored in freezer for not longer than 28 days, were employed. Dental surfaces were abraded so that a dentine area larger than 6 mm of diameter was exposed. The specimens were divided in four groups: I - control, with primer application previously cement insertion, in agreement with the maker's instructions; and the other received the following treatments before the application of the primer and cement: II - polyacrylic acid; III - maleic acid; IV - laser. Specimens were maintained in distilled water at 37ºC for 24 hours, until they be submitted to Instron machine's shear bond strength. Based on the variance analysis and on Duncan's test, the following conclusions were obtained: the pre-treatments propitiated different effects and significant statistically on the shear bond strength; the group control and the maleic acidpropitiated the same medium resistances to the shear bond strength and the best than the polyacrylic acid and the laser; the use just of the primer it showed one of the largest resistance values to the shear bond strength, being, therefore, the choice pre treatment for Vitremer