Hydroxyapatite formation on surface of calcium aluminate cements

In this study, we report the formation and characterisation of a calcium aluminate cement for potential application as a hard tissue replacement. Phase pure monocalcium aluminate powder was synthesised using the Pechini technique, using a relatively low temperature (1000 degrees C) and sintering time (3 h). Characterisation of the hardened material showed a strong relationship between the liquid/powder ratio to which the cement was mixed and the mechanical performance of the hardened materials with little influence on cement microstructure. Interestingly, following immersion in phosphate buffered saline, there was extensive precipitation on the surface of the cement sample. X-ray diffraction showed that the precipitate was hydroxyapatite, which on evaluation using scanning electron microscopy was shown to be of porous structure.