Effect of the concentration of carbonate groups in a carbonate hydroxyapatite ceramic on its in vivo behavior

Carbonate-substituted hydroxyapatites containing up to 9 wt % of carbonate groups were synthesized and fabricated in the form of porous granules with a view to developing materials for use in bone tissue repairs. The use of sintering additives forming a liquid phase allowed the granule sintering temperature to be reduced by 400–450°C. It was found that the carbonate groups enter into the structure of the ceramic by a mixed AB-type substitution; the microstructure of the granules depends substantially on the concentration of the carbonate groups; introduction of 6 wt % of carbonate groups into apatite ensures high biological properties of the granules in experiments in vivo.