Lyophilized bone allografts in periodontal intraosseous defects

Nine patients with 10 pairs of intraosseous periodontal defects were treated. Most of the patients had identical bilateral lesions (referred to as "mirror-image" defects). In each pair, one of the defects was randomly selected and treated as a flap and currettage control whereas the other defect was grafted with freeze-dried cortical powdered allografts of bone. Evaluation was based on radiographs, photographs, and measurements taken during both the initial surgery and at reentry approximately 1 year after transplantation. Control procedures (flap and curettage) demonstrated the same amount of osseous regeneration as that seen with the graft procedure. The amount of osseous regeneration demonstrated with the grafting procedures agreed with previously published studies. Evaluation revealed that (1) an autologous control such as incorporated in the "mirrow-image" design of this study is probably the most valid experimental model available for evaluating the clinical effectiveness of any human periodontal grafting procedures; (2) the effectiveness of freeze-dried cortical powdered bone allografts in human periodontal osseous defects is questionable and needs additional study; and (3) nongrafting procedures may be more effective in generating new attachments or reattachments in human periodontal osseous defects than previously believed.