Peri-implant lesions are directly linked to the relationship between the implant and the soft tissue. These lesions are rare in the case of pure Ti smooth implants, but appear frequently around the rough-surfaced implants. A marginal inflammation may result in a rapid peri-implant bone loss, since the peri-implant connective tissue constitutes in a less effective barrier than the same tissue surrounding the tooth. The morphopathological examination of the peri-implant tissues revealed after their removal that the gum's mucous membrane is not inflamed, but degenerative lesions were observed both on the epithelium and chorion. The papillary lamina propria contains few cells, but it is rich in collagen fibers; vasodilatation and edema were also present. Multiple areas of lysis of the intercellular junctions were also observed at the intermediary level of the gum peri-implant epithelium (the epithelial cells undergo a process of involution at the intermediary level of the epithelium). Important changes can be seen both at the level of intercellular junction systems and at the junction between the basal extremity of the epithelial cells and the basal membrane.