Periodontal Regeneration Using Recombinant Human Bone Morphogenetic Protein-2 and a Bilayer Collagen Matrix

Previous studies demonstrated that recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered using a collagen sponge could be a candidate for periodontal regeneration therapy. However, there is little evidence related to rhBMP-2 delivered with a bilayer collagen matrix. The aim of this study was to investigate the proper dose of rhBMP-2 using a bilayer collagen matrix for periodontal regeneration in a 1-wall defect. The mandibular first premolars and first molars of 6 beagle dogs were extracted, and an 8-week healing period was allowed. One-wall intrabony defects (4 mm in width and 5 mm in height) were made on the mesial side of the 2nd premolar and/or the distal side of the 4th premolar bilaterally. Subsequently, a bilayer collagen matrix containing 0 mu g (C), 200 mu g (T1), or 500 mu g (T2) of lyophilized rhBMP-2 was randomly applied to the defect area. Calcein and xylenol orange were injected at 4 and 8 weeks following the surgery, respectively, to label periodic bone formation. After a 12-week healing period, the animals were sacrificed for micro-computed tomography and histomorphometric analysis. Bone mineral density and bone volume density showed statistically significant differences between the control group and group T1, while no significant differences were observed between the control group and group T2 or between groups T1 and T2. The bone height in groups T1 and T2 was smaller than that in the control group. Low doses of rhBMP-2 delivered using a bilayer collagen matrix in 1-wall intrabony defects can promote periodontal regeneration compared to no or high doses of rhBMP-2.