Early healing of peri-implant mucosa in man

AIM: To analyse (i) cellular and vascular densities in the connective tissue interface portion of the peri-implant mucosa and (ii) tissue interactions with the titanium surface during early stages of healing.MATERIALS AND METHODS: Circumferential biopsies of peri-implant soft tissues were retrieved together with custom-made abutments at 27 implants in 21 patients after 2, 4, 6, 8 and 12 weeks of healing. Following fixation, the peri-implant soft tissue was separated from the abutments, divided into four units and embedded in paraffin. Sections were produced and prepared for immunohistochemical analysis. The abutments were examined by SEM.RESULTS: T and B cells occurred in clusters with a decreasing cell density from 4 to 8 weeks of healing in the connective tissue lateral of the abutment. Macrophages were evenly distributed in the connective tissue along the abutment/tissue interface, while polymorphonuclear (PMN) cells were confined to the tissue portion lateral to the junctional epithelium. Vascular structures showed a decrease in density from 2 to 8 weeks of healing. SEM analyses of the abutments revealed an increased presence of tissue remnants attached to the surface with increasing healing time. A biofilm was consistently observed in a supra-mucosal position, apical of which a "clear zone" occurred that separated the tissue remnants and the biofilm.CONCLUSION: Onset and resolution of inflammation together with increasing tissue attachment to the implant characterize healing of peri-implant mucosa.