Biologic and clinical considerations for autografts and allografts in periodontal regeneration therapy.

Although complete periodontal regeneration is unpredictable with any regenerative therapy currently used, periodontal bone grafts show strong potential. A large body of clinical evidence clearly indicates that grafts consistently lead to better bone fill than nongrafted controls. Regardless of which material is used, the average bone fill is 3 mm, or about 60% defect fill according to reported studies. In addition, histologic analyses now show conclusively that regenerative treatment with bone grafting leads to some degree of regenerated bone, cementum, and periodontal ligament. Although bone grafts and other periodontal treatments have improved clinicians' ability to promote osteogeneration, the outcomes are still somewhat unpredictable. Part of the problem is that it is still unclear how periodontal disease affects the supporting bone's regenerative potential and what specific biologic factors are involved. In recent years, however, clinicians have begun to learn much more about how periodontal regeneration works on a cellular and molecular level. This is a key step to developing strategies and materials that allow clinicians to promote periodontal regeneration predictably. Since its introduction during the last decade, GTR has been an invaluable addition to the armamentarium, as has the recognized importance of early wound stability. As more is learned about the biologic process of periodontal regeneration, new materials and techniques, such as growth factors, absorbable membranes, and new graft materials, are expected to make the task of periodontal regeneration even more predictable. It is likely that some combination of techniques may eventually prove to yield the best results.