Rhb-NGF and rhBMP2 refine regenerated bone

Objective: To evaluate the quality of regenerated bone in periodontal tissue regeneration, following topical application of recombinant human beta nerve growth factor (rhb-NGF) and recombinant human bone morphogenetic protein-2 (rhBMP2) to furcation class III defects. Methods: Thirty-six inflamed furcation class III defects were surgically created in six beagle dogs, which were 5 mm high at the location of mandibular premolar 2, 3 and 4, then biodegradable gelatin hydrogel incorporating rhBMP2 and rhb-NGF was topically applied to the defects. They were divided into 6 groups: G1: untreated as the control group A, G2: gelatinous carrier alone as the control group B, G3: 0.4% rhBMP2 + gelatinous carrier, G4: 2% rhb-NGF + gelatinous carrier, G5: 0.4% rhBMP2 + 2% rhb-NGF + gelatinous carrier, and G6: 0.2% rhBMP2+ 1% rhb-NGF + gelatinous carrier. Eight weeks after application, scanning electron microscopic (SEM) observation and calcium/phosphorus ratio (Ca/P ratio) analysis of regenerated bone were assessed. Results: The mean Ca/P ratio (with standard deviations) of regenerated bone in the 6 groups was: 1.24 ± 0.05, 1.26 ± 0.03, 1.33 ± 0.06, 1.44 ± 0.04, 1.55 ± 0.03 and 1.43 ± 0.09, respectively, with a significant difference between rhb-NGF-applied groups and 2 control groups (all p<0.01). The Ca/P ratio of G3 was higher than that of 2 control groups (p<0.05), and it was lower than that of G4 (p<0.05). The Ca/P ratio of G5 was the highest among all groups (all p < 0.01). The SEM study showed more calcified substances on the collagen fibril surface of G5 than other groups. Conclusion: These results indicate that a topical application of rhBMP2 and rhb-NGF can improve the regenerated bone quality in artificially created furcation class III defects of beagle dogs.