Periodontal Regeneration by BMP-2 Application to Root Dentin Surface

Abstract

The objective of this study was to evaluate periodontal regeneration in canine premolars after application of bone morphogenetic protein (BMP)-2 to root dentin surfaces.
Eighty periodontal defects using a dehiscence model were surgically produced on the buccal roots of premolars of six beagles. After a partial thickness muco-gingival flap was elevated, soft tissues including the periosteum, the periodontal ligament and the cementum were removed. Subsequently, denuded dentin surfaces were demineralized with 24% EDTA, 0, 100, 400, 1000μg/ml BMP-2 solutions were applied, and then labeled as groups 0, 100, 400, 1000, respectively. In the untreated, control group, root dentin was neither demineralized nor was BMP-2 applied. Histological and histometrical analyses were performed at four and eight weeks after surgery.
At eight weeks, new cementum formation in the 1000 group was significantly greater than the 0 group. Cementum formation in the control group was significantly suppressed compared with all the other groups. Interestingly, cementum-like tissue which was expressed discontinuously to the residual cementum was observed in the 100, 400 and 1000 groups.
Ankylosis, which was exclusively observed in the coronal part of newly formed bone, was occasionally displayed in groups 400 and 1000 at four weeks. At eight weeks, ankylosis was rarely demonstrated in any group.
New bone formation extended to the coronal area from the residual alveolar bone in all groups. At eight weeks, new bone in the 400 and 1000 groups was significantly greater than the control and 0 groups.
Down-growth of the junctional epithelium in the 400 and 1000 groups was significantly smaller than that in 0 group.
These results suggest that BMP-2 application to the root dentin surface may be conductive to periodontal tissue regeneration.