Aim: The aim of the study was to evaluate the impact of BMP on the resorption and degradation of a calcium phosphate ceramic.
Materials and methods: Four bone substitute discs (15 mm × 5 mm) were implanted in 10 Gottingen Minipigs (Group I [ n = 5]: HA vs. HA/TCP, Group II [ n = 5]: TCP vs. HA/TCP). Two scaffolds were supplied with 250 μg Bone Morphogenetic Protein-7 (BMP-7). An intraperitoneal fluorochrome bone labeling was performed. Computed tomography was performed in vivo every 4 weeks. The animals were sacrificed 14 weeks after surgery. Specimens were evaluated by Environmental Scanning Electron Microscopy and by fluorescence microscopy. Osteoclasts were evaluated by a TRAP staining.
Results: Newly formed bone was seen in all implants, even in absence of BMP. Bone formation ( p = 0.001) and ceramic degradation ( p = 0.001) was enhanced in presence of BMP-7 in the HA and in the HA60 group. In those groups osteoclasts were observed. BMP-7 did not show any statistical effect on ceramic degradation after 14 weeks on TCP, no osteoclasts were observed.
Conclusions: All studied ceramics were osteoinductive. HA and HA/TCP ceramics are suitable carriers for BMP-7. BMP accelerates bone resorption, while bone formation will be enhanced. The fast breakdown of TCP is interpreted as a result of degradation as no osteoclasts were seen.
Conflict of interest : None declared.