Violation of the biologic width could induce different periodontal consequences depending on many factors such as the type of the restorative material used. In this study, the histological performance and the marginal adaptation of three filling materials (amalgam, composite resin and compomer) are evaluated after a period of three months. Class V cavities with apical margin located at the alveolar bone crest were prepared on Pointer dogs teeth and restored with these three materials. Histological analysis showed that lesions in epithelial attachment were mainly noticed with amalgam fillings and the scale of inflammatory cells was the highest when amalgam was used. Compomer showed the best marginal adaptation.