Solution property of calcium phosphate cement hardening body

In this paper, the solution property of calcium phosphate cement (CPC) hard ening bodies with various ratios of calcium to phosphate were studied. The solution property included solubility and behavior in simulated blood phosp horic acid solutions with selected initial concentrations at 37 degrees C. When the ratios of calcium to phosphate were 1.67, 1.60, 1.55, 1.50, the so lubility products, -log K-sp, were 99.2-102, 94.7-94.8, 89.6-90.5, 85.5-86. 4, respectively. All these were significantly bigger than the values report ed by the references due to the low crystallinity and calcium deficiency in the calcium phosphate cement hardening body. When CPC with Ca/P = 1.50 was immersed in fixed volumes of simulated blood plasma, both the calcium and phosphate concentrations in the solution increased, while for the samples w ith a ratio of 1.67, the concentrations decreased. These results showed tha t the simulated blood plasma was supersaturated when Ca/P = 1.67 but unsatu rated Ca/P = 1.50. It was deduced that when CPC was implanted in the bodies , the specimen with the ratio of 1.5 was degraded faster than with the samp le of 1.67. 1999 Elsevier Science S.A. All rights reserved.