The physicochemical properties of the solidification of calcium phosphate cement

In this article, the physicochemical properties of the solidification of calcium phosphate cement (CPC) were investigated, and the components of the solidified body and the characteristics involved in the application were measured. The setting process of CPC was moderate and slightly exothermic, the heat liberation rate was slow, and the temperature increased little. At the initial stage of the hydration, the compressive strength rose linearly with time, and reached the maximum value after 4 hours. The volume was slightly shrunken by 1% during the setting process, and the total heavy metal content was below 2 ppm. The porosity of the solidified body was about 30%, which was mainly the gel pore with size below 0.1 mum. The final product of hydration was low crystalline hydroxyapatite (HAP). Its real density was 2.859 g/cm(3), which was lower than the theoretical value. This may be due to the existence of lattice defects, which will lead to a slight rise in solubility when leached in physiological saline. (C) 2004 Wiley Periodicals, Inc.