BONE MORPHOGENETIC PROTEIN-2 FOR PERI-IMPLANT BONE REGENERATION AND OSSEOINTEGRATION

Recombinant human bone morphogenetic protein-2 (rhBMP-2) induced bone regeneration and osseointegration was evaluated in supraalveolar peri- implant defects in 5 beagle dogs. Alveolar bone was reduced 5 mm in he ight in mandibular premolar areas and the premolars were extracted. Th ree 10 mm titanium fixtures were placed 5 mm into each reduced alveola r crest, leaving 5 mm in a supraalveolar position. Alternate quadrants in consecutive animals received a surgical implant consisting of 2 ml rhBMP-2 (0.43 mg/ml) in a type I bovine collagen carrier, or the carr ier alone (control). Fixtures and surgical implants were submerged und er the gingival flaps. The healing interval was 16 weeks. Histometric and radiographic evaluations were made. Defect height averaged (+/-SD) 5.3+/-0.2 and 5.1+/-0.2 mm for rhBMP-2 and control defects, respectiv ely (P>0.05, n=5, paired, t-test) Bone regeneration (height) averaged 4.2+/-1.0 and 0.5+/-0.3 mm for rhBMP-2 and control defects, respective ly (P<0.05). Bone regeneration (area) averaged 6.1+/-6.3 and 0.2+/-0.2 mm(2) for rhBMP-2 and control defects, respectively (P>0.05). Osseoin tegration within the confines of the defect averaged 19.1+/-10.1% and 8.2+/-4.6% for rhBMP-2 and control defects, respectively (P>0.05). Oss eointegration within regenerated bone averaged 29.1+/-9.8% and 65.3+/- 15.3% for rhBMP-2 and control defects, respectively (P<0.05). Osseoint egration within the retained alveolar bone averaged 67.1+/-4.6% and 68 .1+/-3.6% for rhBMP-2 and control defects, respectively (P>0.05). The results suggest that there is a potential for rhBMP-2 induced bone reg eneration and osseointegration in surgical peri-implant defects.