Preparation of calcium pyrophosphate glass-ceramics containing Nb ₂O₅

New types of calcium phosphate glass-ceramics were prepared with the addition of Nb₂O₅ to the pyrophosphate region. The glassceramics contained α-Ca₂P₂O₇, β-Ca₂P₂O₇, and orthorhombic Nb ₂O₅. The concentrations of Ca, P and Nb elements released from the glass-ceramics were lower than those released from glass of the same chemical composition. Apatite formed on the surface of the glass-ceramics after soaking in 1.5 simulated body fluid for 7 days. The crystal phases of the glass-ceramics improved the chemical durability and apatite forming ability of the material.