Periodontal tissue regeneration by recombinant human osteogenic protein-1 in periodontally-induced furcation defects of the primate Papio ursinus : research article

Bone-derived bone morphogenetic/osteogenic proteins (BMPs/OPs) regenerate alveolar bone and cementum in surgically created furcation defects in the Chacma baboon (Papio ursinus). Recent studies showed the induction of cementogenesis by relatively low doses of human recombinant osteogenic protein-1 (hOP-1), suggesting that BMPs/OPs might possess a structure/activity profile that controls tissue morphogenesis and regeneration. More challenging is the demonstration of cementogenesis and bone regeneration in periodontally induced furcation defects with root surfaces exposed for a relatively long time to periodontal pathogens. Baboons experience naturally occurring site-specific gingivitis but periodontitis, as defined by loss of periodontal attachment, has not been found in any of twenty animals in our colony. A pathogenic human strain of Porphyromonas gingivalis was inoculated into the furcation areas of the 1 st and 2nd mandibular molars of four adult baboons twice a month for twelve months; follow-up examinations included sulcular probing depths and microbiological analyses of subgingival plaque. Chronic periodontitis was induced in all four animals as assessed by probing periodontal pocket depths, intra-oral radiographs, and microbiological analyses that confirmed the presence of P gingivalis. Two months after scaling, root planing and a plaque control regimen with clinical resolution of gingivitis, mucoperiosteal flaps were elevated to expose class 11 furcation defects of the affected molars filled with copious granulation tissue. After root planing and debridement, 12 furcation defects were implanted with 0.5 or 2.5 mg of gamma-irradiated hOP-1 per 1 g of xenogenic bovine insoluble collagenous bone matrix as carrier. Serial undecalcified sections prepared six months after surgery showed regeneration of alveolar bone and induction of cementogenesis with Sharpey's fibres uniting the regenerated bone to the newly induced cementum with both doses of hOP-1. These results indicate an additional specific use of hOP-1 for tissue morphogenesis in clinical contexts.