Preparation and in vitro bioactivity of CaSiO3 powders

Fine CaSiO3 powders were prepared by chemical precipitation with ultrasonic stirring using Ca(NO3)2·4H2O, Si(OC2H5)4 as source material and 0.25 mol/l NaOH as a precipitant. The characteristics of the resultant powders were negatively affected by the presence of the Na component. For this reason, the precipitates were washed with distilled water in order to remove the Na component. The washed precipitates were calcined at 500 and 900 °C. The ground and sieved powders were sintered at 1000 and 1200 °C to bulk density values of 1.49 and 2.035 g/cm3, respectively. The minimum porosity of 5.00% was obtained on pellets pressed at 240 MPa and sintered at 1200 °C. The sintered pellets at 1200 °C were soaked in simulated body fluid (SBF) solution and hydroxyapatite (HAp) layer formed as ball-like particles on the surface of the CaSiO3 samples after soaking for a short time.