Implant site development: clinical realities of today and the prospects of tissue engineering

The success of dental implants depends on their placement in bone of adequate density and volume in order to achieve primary stability. Optimal esthetics of implants requires their placement in a position approximating that of the natural teeth they replace. However, there is generally at least some degree of atrophy in the sites where implants are to be placed. This atrophy may occur either before or after tooth extraction. Following extraction of teeth, there is commonly alveolar ridge resorption in horizontal and vertical dimensions. Alternatively, some of the oral hard and soft tissues may be destroyed by pathologic conditions such as periodontitis, endodontic infections, or trauma. All of these conditions may potentially compromise the final esthetics and function of implant-supported restorations. During the initial years of the development of the osseointegration protocol, implants were placed with little or no modification of implant sites. Though osseointegration was successfully achieved, esthetic outcome was not a primary objective of therapy at that time. A gradual paradigm shift has occurred in implant dentistry from merely achieving successful osseointegration to achieving final restorative outcomes that mimic natural dentition and their surrounding oral tissues. These objectives have been materialized by advancements in surgical techniques, as well as availability of biomaterials to enable predictable regeneration of oral hard and soft tissues. The objective of the present review is to briefly discuss some of the techniques that are currently available for implant site development.