The insertion of any given foreign material in a bone site is a multifaceted problem that involves the implant, the adjacent tissue, and the interface between implant and tissue. Implant parameters of concern include chemical composition, surface conditions, and mechanical factors such as yield strength, tensile strength, and elongation. The tissue´s reaction depends on its unique capacity to adapt itself to various external stimuli and its ongoing vitality. It is also essential that the tissue remain in the closest proximity to the implant. The interfacial behavior between implant and tissue is determined not only by the nature of the implant and the state of the tissue per se, but also by the technique of inserting and loading the implants. This review summarizes the biologic aspects of archieving integration of titanium implants in host bone tissue. (J Prosthet Dent August - 1983)