Polypeptide growth factors for periodontal regeneration.

The regeneration of periodontal attachment apparatus is particularly difficult to achieve, primarily because of the presence of many different kinds of tissue that must be restored to produce a functional unit. Traditional methods aimed at regenerating the periodontium have limited indications, and their results are not predictable. Recently, investigators have begun to understand the cellular processes necessary for repair and regeneration of periodontal tissues. Proteins called growth factors have been identified that coordinate these cellular events. The growth factors that may contribute to periodontal regeneration include platelet-derived growth factor, insulin-like growth factor, transforming growth factor-beta, and bone morphogenetic proteins. In vitro studies have demonstrated the positive effects of these factors on a number of cell types essential for periodontal regeneration. For instance, it has been shown that platelet-derived and insulin-like growth factors promote proliferation of osteoblasts an periodontal ligament cell-derived fibroblasts. Animal models have also been used to verify that growth factors can enhance regeneration in vivo following periodontal disease and as an adjunct to implant placement. In the future, human clinical trials will be required to identify the ideal growth factors, their proper doses, and the most suitable carrier system for them.