[An experimental study on the osteoconductive properties of porous calcium phosphate glass ceramics]

Porous blocks of calcium phosphate glass ceramics (CaO 52 mol %, P2O5 47 mol %, Al2O3 1 mol %, mean pore size 200 microns, mean porosity 85%) were implanted in the distal femoral metaphysis of rats and were observed for up to one year. The materials were evaluated histologically and morphometrically using contact microradiography and Masson-Goldner staining. Comparative experiments were conducted employing similar methods as described above, with calcium phosphate glass ceramics, sintered hydroxyapatite and alumina ceramics, each having 70% porosity. The compressive strength of each implanted material was measured at a certain intervals up to 6 months after implantation. Bone formation was seen from the periphery to the center of the block. Mass of the regenerated bone and infiltrating depth of the new bone increased with the passage of time. New bone formation with the glass ceramics was observed to be almost equivalent to that obtained with hydroxyapatite, and was significantly higher than that with the alumina ceramics.