抄録
Spherical β-tricalcium phosphate (β-TCP) granules composed of rod-shaped particles are expected to be useful as bioresorbable bone substitutes. The β-TCP granules can be prepared by the heat treatment of Ca-deficient hydroxyapatite (HA) granules that are synthesized by hydrothermal treatment of α-TCP granules. However, when the Ca/P molar ratio of Ca-deficient HA becomes higher than 1.50, depending on the hydrothermal conditions, not only the β-TCP but also the HA phase appears following heat treatment. To resolve this problem, phosphate ions were incorporated into the Ca-deficient HA granules or monetite was added to decrease the Ca/P molar ratio to less than 1.50 in the starting composition. We revealed that these processes were effective in obtaining the pure β-TCP granules composed of rod-shaped particles and thus preventing the formation of HA.