Preparation of calcium strontium hydroxyapatites by a new route involving calcium phosphate cements

A new route, based on the use of ionic calcium phosphate cements, has been developed to synthesize hydroxyapatite. Cements were prepared from tetracalcium phosphate, α–tricalcium phosphate, phosphoric acid, strontium nitrate, and water. They were then mixed and shaped. Cements with various amounts of strontium and different (Ca + Sr)/P atomic ratios were prepared. All the materials obtained were coherent and solid. When the amount of strontium was low, mixed hydroxyapatite was obtained at low temperatures. Mixed calcium strontium apatite was obtained after heating. This original method can be of interest in various fields such as biomaterials or the storage of radioactive waste.