In vivo reactions of Ca,P particle containing surface reactive glasses

Four Ca,P particle containing surface reactive glass composites and two glasses (in the SiO2-CaO-P2O5-Na2O-Al2O3-B2O3 system) were implanted in the diaphyseal area of goat femora up to 24 weeks. Scanning electron microscopic, energy dispersive x-ray, and histological analysis were performed to evaluate the material-tissue interactions. A new type of integration mechanism was observed. Instead of the bone growing to the material surface, a gel-like silica formation appeared between the cortex bone and the material surface. In time the gel-like formation was replaced by a Ca,P layer. The results provided indirect evidence that pure silica gel formed in the tissues could also achieve an apatite layer formation and bone bonding on its surface.