Recapitulating development: a template for periodontal tissue engineering

The induction of bone formation by the soluble osteogenic molecular signals of the transforming growth factor-beta (TGF-beta) superfamily is a critical issue to periodontologists, molecular biologists, and tissue engineers alike, because preclinical studies in primates and clinical trials have demonstrated the bone induction capacity of bone morphogenetic and osteogenic proteins (BMPs/OPs) in clinical context. BMPs/OPs, pleiotropic members of the TGF-beta superfamily, induce de novo endochondral bone formation as a recapitulation of embryonic development and act as soluble signals for tissue morphogenesis sculpting the multicellular mineralized structures of the periodontal tissues with functionally oriented periodontal ligament fibers inserting into newly formed cementum. This paper reviews the induction of the complex tissue morphologies of the periodontal tissues in the nonhuman primate Papio ursinus with furcation defects treated with doses of naturally derived and recombinantly produced human BMPs/OPs. Periodontal tissue regeneration develops as a mosaic structure in which the OPs of the TGF-beta superfamily singly, synergistically, and synchronously initiate and maintain tissue induction and morphogenesis.