Bioresorbable collagen membrane as a carrier for recombinant human bone morphogenetic protein-2 on lateral onlay grafts in dogs

Abstract

The objective of this study was to evaluate bone regenerative effect of bioresorbable collagen membrane (CM) as a carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) when performing lateral onlay graft using bovine hydroxyapatite incorporated with collagen matrix (BHC) in combination with CM in dogs. A guided bone regeneration procedure was performed at the buccal aspect of edentulous maxillary alveolar ridges using two treatment modalities in dogs (N=5): (1) BHC group, in which rhBMP-2-loaded BHC was covered by a CM, and (2) CM group, in which BHC was covered by an rhBMP-2-loaded CM. A histologic and histometric analysis was performed after 8 weeks of healing. Both the BHC and CM groups exhibited substantial new bone formation that was well integrated with the native bone. More newly formed bone was found in the CM group than in the BHC group without statistical significance. Most of the newly formed bone was in direct contact with the residual bone substitute in the BHC group, whereas the projections and islands of newly formed bone were observed in the spaces between the residual bone substitute clusters in the CM group. The bone-to-residual biomaterial contact ratio was significantly lower in the CM group than in the BHC group (p<0.05). Within the limitations of the present study, it was found that rhBMP-2-loaded CM was effective for inducing the formation of new bone in the lateral onlay graft procedure. This implies that soaking CM with rhBMP-2 solution could simplify the surgical procedure.