Effects of ions traces on the dissolution of bioceramics composed of hydroxyapatite and β-tricalcium phosphate

Abstract

The aim of this work is to study the effect of trace ions as Mg 2+ , Sr 2+ , (SiO 4) 4-and Al 3+ , brought by the raw material, on the dissolution of the calcium-phosphate bioceramics. The precursor powders prepared by aqueous precipitation with molar ratio Ca / P = 1.630 ± 0.002, were calcined at 1100°C resulting in the formation of a mixture of hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2) and β-tricalcium phosphate (β-Ca 3 (PO 4) 2). Two mixtures which differ by the content of trace ions were characterized for phase purity, chemical composition and morphology. The dissolution tests were performed at 37 °C in acidic buffers solution at pH 4.8. The results showed that the dissolution of calcium ions is more important in the presence of ions trace while the phosphor ions were not affected. The dissolution and dissolution-reprecipitation observed of various ions trace can modify the surface properties of calcium phosphate bioceramics and therefore the properties of biological products, such as resorbtion and reactivity can be affected.