Freeze-dried dura mater allografts (FDDMA) were used as a biologic bandage covering periodontal osseous defects which were grafted with autogenous bone particles. Seven consenting adult patients having multiple one-, two-, and wide three-wall periodontal osseous defects participated in the study. Four to 6 weeks following initial preparation, all defects were treated by full thickness flap surgery, debridement of defects, root planing, intramarrow penetration as needed, and autogenous bone grafts that filled the defects. Randomly selected grafted defects in each patient were then covered with FDDMA (experimental) or by the host flap (RF) (control). Periodontal dressing and systemic tetracycline (250 mg q.i.d.) were used for 7 days. Frequent maintenance was performed until reevaluation at 6 months postsurgically. Soft tissue results showed no significant differences in initial probing pocket depths, recession, or gain of probing attachment. There was a significantly greater amount of probing pocket depth reduction and significantly shallower residual pockets when FDDMA was used. Hard tissue findings indicated that there were no significant differences in initial defect depth, amount of crestal resorption, or amount or percent of defect fill with either treatment. There were significant differences in the percent of defect resolution and the depth of the residual defect in favor of the FDDMA treatment. None of the FDDMA sites were felt to need a secondary surgery to correct residual defects or residual pockets. This study suggests that FDDMA may be beneficial as a "biologic bandage" to cover periodontal osseous defects that were filled with autogenous bone grafts. The trends in this study suggest that FDDMA may be very useful in periodontal regeneration procedures.