Morphologic Evaluation of Clinical Long-Term Percutaneous Titanium Implants

In this study, the soft tissue around 23 percutaneous Brånemark titanium implants was studied using light microscopic morphometry. The duration of the skin penetration varied between 4 and 98 months. The results show that phagocytic and immunocompetent cells (lymphocytes, polymorphonuclear granulocytes, plasma cells, and macrophages) were present in biopsies from patients with irritated as well as nonirritated skin around the implants. The concentration of inflammatory cells was higher in the tissue close to the implant and in this region particularly just beneath the epithelium. The concentration of inflammatory cells in irritated skin did not differ statistically from nonirritated skin. This was probably related to the fact that the grade of skin irritation generally was low in the material and to the relatively small amount of material investigated. The present observations suggest that a cellular barrier of phagocytic and immunocompetent cells may be operative around percutaneous titanium implants. The mechanisms for the clinically manifest irritation and reinforced cellular barrier function are not known but may be related to both the implant per se and to invasion by exogenous agents. Keywords: histology, inflammation, percutaneous implant, titanium