Effect of CaF₂ on preparation and in vitro bioactivity of tricalcium silicates

The different amounts of CaF₂ were added to prepare bioactive tricalcium silicates (3CaO · SiO₂, C₃S) by solid-state reaction. The effect of CaF₂ on the preparation and in vitro bioactivity of C₃S were investigated by chemical titration, TGA/DTA, XRD and SEM. CaF₂ accelerated the decomposition of CaCO ₃ at lower temperature. The formation of C₃S was accelerated with the help of the eutectic mixture. The phase transformation and decomposition of C₃S were retarded by the addition of CaF₂ during quenching in air. The quality of C₃S was improved effectively by doping CaF₂. The surfaces of CaF₂ doped C₃S and pure C₃S were covered by apatite deposite after soaking in simulated body fluid (SBF) for 1 day and 3 days, respectively. It indicates that the bioactivity of C₃S is improved by doping CaF₂.