[Pathomechanisms of impaired wound healing by metallic corrosion products].

BACKGROUND: Metallic materials of variable chemical composition have been used in dental practice for a long time. Complications with respect to tissue healing after insertion of implants are well documented. In this paper we present relevant aspects of the related fields of inflammation and repair processes and focus on the pathomechanisms of this impaired healing response. MODULATION OF WOUND HEALING: This latter process is modulated by specific metal ions released by corrosion activity as well as by wear particles, which influence the function of the participating cell types (e.g. endothelial cells). IN VITRO MODELS: In this context, in vitro models are presented that permit study of isolated aspects of the complex sequence of events at the biomaterial-tissue interface. Furthermore, newly developed, computer-assisted methods allowing an objective quantification of biomaterial/corrosion product-induced effects on complex processes, such as angiogenesis in vitro, are demonstrated. Because of the central importance of titanium implants in maxillofacial surgery, new experimental approaches to study possible negative effects are presented. Finally, the relevance of such studies for clinical implantology is evaluated.