Preparation of Calcium Phosphate Cement Utilizing Dicalcium Phosphate Dihydrate and Calcium Carbonate

Calcium phosphate cement has been widely used as a bone substitute because of its chemical similarity to natural bone. In this study, calcium phosphate cement was prepared using dicalcium phosphate dihydrate (CaHPO4.2H2O) and calcium carbonate (CaCO3) as starting raw materials. The cement pastes were mixed and the chemistry adjusted with two different aqueous solutions of sodium hydroxide (NaOH) and disodium hydrogen phosphate (Na2HPO4). Concentrations of the solution were varied in the range 0.5 to 5.0 mol/L with the ratio of solid/liquid = 2 g/ml. The cement paste was then poured into a silicone mold having a diameter of 10 mm and a height 15 mm. Setting times for the cement were measured using a Vicat apparatus. XRD, FT-IR, and SEM techniques were used to characterize properties and microstructure of the cement. From the experimental results, it is clear that different concentrations of Na2HPO4 and NaOH have affected the setting times of the cement. The relationship between concentration of NaOH and Na2HPO4 and setting time, including final properties of the cement, is discussed.