Katsuhiko Satoh

Hardening of β-tricalcium phosphate (β-TCP) mixed with a 2.5wt% Na2HPO4 aqueous solution was investigated by a compressive strength test, XRD, SEM, and calorimetry. The β-TCP starting material was ground using a mortar grinder for 7, 24, and 72 h in an air atmosphere. Compressive strength for β-TCP cement ground for 24 h was stronger than that ground for 7 h and 72 h, and was 42.8±4.1 MPa after soaking in saline for 7 days. It was found that β-TCP requires rapid hydrolysis to harden β-TCP cement. The Na2HPO4 aqueous solution facilitates this hydrolysis reaction. The compressive strength of β-TCP cement depends on the length and the number of acicular apatite crystals deposited from β-TCP.