Development of calcium phosphate ceramics of controlled Ca/P ratio as a bone substitute

ABSTRACT

In this paper, an attempt was carried out to produce calcium phosphate ceramics whose composition comes close to that of natural dry bone. Dicalcium phosphate dihydrate [CaHPO4.2H20] and calcium carbonate [CaCO3] were mixed at different proportions so that three batches of ceramics whose Ca/P ratio are 1.5, 1.7 and 1.9 are obtained. These ratios lie in close vicinity to the reported data for dry cortical bone [Ca/P =1.67]. Sintering was carried out at temperatures ranging from 1100 to 1350°C. The variation in batch composition as well as in sintering temperature has proved to play a decisive role in determining the end product characteristics. Parameters such as bulk density, porosity, firing shrinkage, modulus of mechanical rupture, mineralogical and textural features and thermal expansion behavior, were studied to assess their matching with those of dry cortical bone