Human Periodontal Ligament Cell Responses to Recombinant Human Bone Morphogenetic Protein‐2 with and without Bone Allografts

Abstract

Background: Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) has been found to promote the osteoblastic differentiation of human periodontal ligament cells. Its effect depends on the delivery system used. In this study we examined the effect of rhBMP‐2 on the proliferation and osteoblastic differentiation of human periodontal ligament cells cultured alone or with 3 different bone allografts. Methods: The rhBMP‐2 effect on cell proliferation and osteoblastic differentiation was examined by measuring [3H] thymidine incorporation and ALPase activity, respectively, on human periodontal ligament (hPDL) cells. Two human demineralized freeze‐dried allografts of cortical (DFDBAco) and cancellous (DFBDAca) bone origin and 1 non‐demineralized freeze‐dried allograft (FDBA) of cancellous bone origin, derived from different tissue banks, were used to evaluate the rhBMP‐ 2 effect on cell osteoblastic differentiation. The measurements were taken on various days. Results: rhBMP‐2 decreased hPDL cell proliferation. rhBMP‐ 2 acted on the third day of the process of cell differentiation, had a specific time of action, achieved its peak effect on the fourth and fifth days, and then did not provoke any further effects. The 3 bone allografts were efficiently combined with rhBMP‐2. The combination of rhBMP‐2 and DFDBAco showed the effect with the longest duration. rhBMP‐2, on day 4, made the inactive bone allograft more active while, on the other days, its effect was dependent on the allograft alone. Conclusions: rhBMP‐2 promotes the osteoblastic differentiation of human periodontal ligament cells and decreases cell proliferation. In this study rhBMP‐2 in the presence of the bone allografts tested resulted in hPDL cell differentiation. J Periodontol 2003;74:982‐989 .