A comparative study on the synthesis mechanism, bioactivity and mechanical properties of three silicate bioceramics.

In the present study three akermanite (Ca2 MgSi2 O7 ), diopside (CaMgSi2 O6 ) and baghdadite (Ca3 ZrSi2 O9 ) applicable bioceramics were synthesized via a sol-gel based method. The combination of sol-gel method and the raw materials used in this study presents a new route for the synthesis of the mentioned bioceramics. By the use of thermal analysis, the mechanisms occurred during the synthesis of these bioceramics were investigated. The differences in the structural density and their relation with the degradation rate and mechanical properties of all three ceramics were studied. In vitro bioactivity and apatite formation mechanisms of the samples soaked in the simulated body fluid were considered. The results showed that baghdadite as a Zr-containing material has a more dense structure in comparison with the other ceramics, which leads to a lower degradation rate and also lower bioactivity. There were also main differences between akermanite and diopside as Mg-containing ceramics. Diopside showed a structure with lower porosity content compared to the akermanite samples which resulted in the lower degradation rate and higher compressive strength.