2020 Volume 128 Issue 11 Pages 962-969
Octacalcium phosphate (OCP) blocks are attractive feedstocks for new biomaterials because of their excellent biocompatibility. Attaching an interconnected porous structure (i.e., a foam) is a good way to use OCP as a bone substitute because this structure allows tissue penetration in the materials. However, the foaming structure shows a lower mechanical strength compared to block-formed materials. In this study, we fabricated OCP foams with enough mechanical strength from calcium dihydrogen phosphate granules of different sizes (100–250, 250–500, 500–1000, and 1000–2000 µm) through a setting reaction using an acidic phosphate solution and a phase-conversion process. The fabricated OCP foams were found to have high enough mechanical strength (>0.5 MPa in diametral tensile strength) and porosity (∼70 %). For small granules, a relatively low concentration of acidic phosphate solution was suitable for the setting reaction.