Functionally Graded Tricalcium Phosphate/ Fluoroapatite Composites

This study was conducted to prepare fluorine-substituted apatite (FA)/beta-tricalcium phosphate (h-TCP) composites to combine the biostability of FA with the bioresorbability of h-TCP. The FAwas prepared for the first time by mixing hydroxyapatite (HA) with aluminium fluoride (coded as AF). On the other hand, the h-TCP was prepared from a mixture of HA and CaHPO4 (calcium hydrogen phosphate). The dissolution behaviour of the composites was tested using a 10-wt.% citric acid solution. Scanning electron microscopy (SEM) indicated that h-TCP dissolved in the citric acid much faster than FA, resulting in macropores among the FA matrix. In addition to bulk FA/h-TCP composites, novel functionally gradient FA/h-TCP composites were also prepared by varying the particle size and the volume content of the h-TCP granules. The functionally gradient FA/h-TCP composites could be used to design implants.