Healing of Spontaneous Periodontal Defects in Dogs Treated with Xenogeneic Demineralized Bone

Abstract

This study was undertaken to histologically, clinicially and radiographically evaluate the sequence of healing following implantation of bovine demineralized bone powder (DBP) into severe, spontaneous periodontal defects in beagle dogs. Eight dogs with documented severe periodontitis were treated surgically following initial debridement. One quadrant in each arch was treated with conventional flap surgery; the others were treated with surgery followed by DBP implantation. Animals received postoperative debridement and clinical and radiographic evaluation. Two dogs were sacrificed at 1, 3, 6 or 12 mo. postoperatively; the jaws were evaluated histologically. Clinically, DBP was well tolerated by recipients. No evidence of localized inflammatory response or delayed hypersensitivity reaction was noted. Significant reductions in gingival inflammation were noted in experimental and control sites at 1 mo. postoperatively compared to preoperative scores. Equivalent periodontal pocket reduction was noted between test and experimental sites and remained significant at 12 mo. Radiographically, no differences were noted in the rate of bone loss between control and test sites. Histologic evaluation demonstrated the presence of DBP at 1 mo. following implantation, but the material was replaced with new bone by the next sacrifice period. Periodontal ligament fibers of standard orientation were seen extending from DBP-induced bone to the root surface by 1 mo. after implantation. An intact epithelial attachment appeared to be present 1 mo. after the implantation of DBP. No differences in root surfaces were detected between test and control groups. Ankylosis was a rare finding, noted equally between test and control sites. DBP did not appear to predispose to external root resorption. In later stages, histologic evidence of advancing periodontitis was noted equally in control and experimental groups. While DBP successfully induced new bone formation, the inabibility to adequately maintain the periodontal tissues due to the bacterial accumulation in this model combined with recurrent pocket formation, precluded any conclusion regarding long-term advantage. Based on these findings clinical trails of this or similar materials are recommended.