Bonding osteogenesis in coralline hydroxyapatite combined with bone marrow cells.

Coralline hydroxyapatite ceramics alone (control) and the ceramics combined with rat marrow cells were implanted subcutaneously in the backs of syngeneic Fischer rats and harvested at 1,2,3,4,6,8 and 24 wk after surgery. None of the control ceramics (without marrow) showed bone formation. However, ceramics combined with marrow cells showed consistent new bone formation in the pore regions. Histometrical results revealed increased new bone formation over time. Undecalcified sections of the ceramics studied by fluorochrome labelling showed that the osteogenesis began directly on the surface of the ceramic and proceeded centripetally towards the centre of the pores (bonding osteogenesis). SEM-EPMA analysis of the bone-ceramic interface also revealed direct bonding of bone to the ceramic surface.