Platelet-derived growth factor-modulated guided tissue regenerative therapy.

The goal of this study was to develop an effective regenerative therapy capable of achieving periodontal regeneration of Class III furcation defects. We attempted to achieve this goal by combining three therapeutic approaches. First, the lesion was protected by an expanded polytetrafluoroethylene barrier membrane that prevents migration of gingival fibroblasts as well as osteogenic cells from the mucoperiosteal flaps. Second, platelet-derived growth factor-BB (PDGF-BB), which has potent chemotactic and mitogenic effects on periodontal ligament fibroblasts (PDL), was used to promote migration of fibroblasts and their proliferation on the root surface. Third, the root surface, demineralized by citric acid conditioning, was chosen as the primary site for PDGF-BB application. The demineralized root surface appeared to have the capability of providing a sustained release of the applied growth factor. This seemed to facilitate rapid repopulation of PDL fibroblasts on the root surface and new PDL formation in the early stages of repair, which contributed to complete periodontal regeneration without root resorption and ankylosis in later stages. Combining these approaches, we developed a therapy referred to as "PDGF-modulated guided tissue regenerative therapy." Unlike guided tissue regenerative therapy alone (without PDGF-BB), this therapy effectively promoted periodontal regeneration of Class III furcation defects in the beagle dog without significant ankylosis or root resorption.