Overview of factors important in implant design.

Forty-two percent of the population over the age of 65 is totally edentulous. The use of dental implants as a means of treating these patients has accelerated in the last decade, and there are now 300,000 dental implants used in the United States. It is therefore imperative that a greater understanding of the parameters which govern the long-term success of implants be developed. In order for the effectiveness of implants to be better quantified, a fundamental, quantitative understanding of the physical parameters governing the complex synthetic material/tissue aggregate is needed. The design of an "optimal" implant requires the integration of material, physical, chemical, mechanical, biological, and economic factors. The approach taken for a specific property objective to be met should be based on a materials science approach, in which the synergistic relationships among processing, composition, structure, and properties are characterized. Implant success is a function of biomaterials and biomechanical factors, including: materials and material processing; mechanisms of implant/tissue attachment; mechanical properties; implant design; loading type; tissue properties; stress and strain distributions; initial stability and mechanisms of enhancing osseointegration; biocompatibility; and surface chemistry, mechanics, and bone-binding ability of the implant. This paper presents an overview of physical parameters important to implantology. Following a general presentation of implantology concepts, the physical parameters listed above are discussed in greater detail.