Osseointegration in clinical dentistry depends on an undertanding of the healing and reparative capacities of hard and soft tissues. Its objective is a predictable tissue response to the placement of tooth root analogues. Such a response must be a highly differentiated one, and one that becomes organized according to functional demands. Since 1952, we have studied the concept of tissue-integrated prostheses at the Laboratory of Vital Microscopy at the University of Lund, and subsequently at the Laboratory for Experimental Biology at the University of Göteborg. Our collaborators in this research have included representatives from medical and dental faculties, various research institutes, and departments of technology. The basic aim has been to define limits for clinical implantation procedures that will allow bone and marrow tissues to heal fully and remain as such, rather than heal as a low differentiated scar tissue with unpredictable sequelae. The studies involved analyses of tissue injury and repair in diverse sites in different animals, with particular reference to microvascular structure and function. Special emphasis was series of different methodological approaches. The objective of this article is a brief review of the various investigations that have led to the clinical application of osseointegration. (JPD September – 1983)