Sinus floor augmentation with recombinant human growth and differentiation factor-5 (rhGDF-5): a pilot study in the Goettingen miniature pig comparing autogenous bone and rhGDF-5

Aim: The aim of this study was to test the hypothesis that recombinant human growth and differentiation factor-5 (rhGDF-5) in combination with a β-tricalcium phosphate (β-TCP) scaffold material results in superior bone formation in sinus floor augmentations in miniature pigs compared with a particulated autogenous bone graft combined with the scaffold material. Material and methods: Six adult female Goettingen minipigs underwent a maxillary sinus floor augmentation procedure. In a split-mouth design, the sinus floors were augmented with β-TCP mixed with autogenous cortical bone chips, in a ratio of approximately 1 : 1, on one side. The contralateral test site was augmented using β-TCP coated with two concentrations of rhGDF-5 (400 μg rhGDF-5/g β-TCP or 800 μg rhGDF-5/g β-TCP; three animals in each case). Simultaneously, one dental implant was inserted into each sinus floor augmentation. After 12 weeks, a histological and histomorphometric assessment of non-decalcified histological specimens was made. Results: There were significantly higher mean values of volume density of newly formed bone using β-TCP coated with two concentrations of rhGDF-5 (400 μg: 32.9%; 800 μg: 23.9%) than with the corresponding control (autogenous bone/β-TCP) (14.6%, 12.9%) (P=0.012, P=0.049). The bone-to-implant contact rates (BIC) were significantly enhanced in test sites (400 μg: 84.2%; 800 μg: 69.8%) compared with the corresponding control sites (24.8%, 40.8%) (P=.027, P=.045). Conclusion: rhGDF-5 delivered on β-TCP significantly enhanced bone formation compared with β-TCP combined with autogenous bone in sinus lift procedures in miniature pigs.