Chloride- and alkali-containing calcium phosphates as basic materials to prepare calcium phosphate cements

Combinations of an alkali-containing calcium phosphate-like rhenanite, sodium whitlockite or calcium potassium phosphate and a chloride-containing calcium phosphate-like spodiosite or chloroapatite with or without additions of other calcium phosphates like monocalcium phosphate monohydrate, dicalcium phosphate or dicalcium phosphate dihydrate were made and mixed with water into pastes. The setting time of these pastes was determined. After soaking for a day in Ringer's solution at 37 degrees C the compressive strength and the diametral tensile strength were determined. Two of the combinations tried in this study resulted in the formation of cements at room temperature. One cement was of the type dicalcium phosphate, whereas the other gave octocalcium phosphate as the solid reaction product. The byproducts formed were an aqueous solution of NaCl and one of K2HPO4, respectively. Applications for bone repair and augmentation are envisaged.