In this study, an attempt was made to examine the effects of 4 glass ionomer cements on pulp. For this purpose, 30 incisors from 3 dogs were employed. Glass-ionomer cements commercially known as Ketac-bond, Kromoglass 1, Vitrebond and Logobond WM were administered in Black Class V cavities drilled on the vestibular surfaces of the teeth, with zinc oxide/eugenol cement being applied to a control group. Teeth were extracted at 7, 30 and 90 days and assessed accordingly. The pulpal tissues of the teeth were reviewed under light microscope with respect to odontoblastic activity, odontoblast aspiration, fibrosis, vascularization and erythrocyte accumulation, presence of inflammatory cells, necrosis, and reparative dentine. Various findings were obtained from 4 different glass-ionomer cements, which were evaluated according to the criteria stated above; however, in no section were inflammatory cells or necrosis encountered. Therefore, none of the substances utilized in our study was found to have an excessive toxic effect on pulpal tissue.