Bioactivity and Osteoconductivity of Biphasic Calcium Phosphates

Abstract

Bioactivity and osteoconductivity of calcium phosphates as a function of ?-tricalcium phosphate contents, that is, biodegradability, were investigated. Three calcium phosphates, pure hydroxyapatite, biphasic calcium phosphates with different mixing ratios between hydroxyapatite, and ?-tricalcium phosphate (60HAp:40?- TCP and 40HAp:60?-TCP in wt.%), were synthesized through the precipitation method using calcium hydroxide and phosphoric acid as starting reactants. After drying, they were sintered at 1100 °C for 3 hours, and then bioactivity and osteoconductivity tests were carried out in simulated body fluid (SBF) and calvarial defect of New Zealand white rabbits, respectively. SBF exposure resulted in the deposition of a layer of carbonate apatite crystals on the surfaces of bicalcium phosphates but not on the hydroxyapatite. New bone forming capacity of the biphasic calcium phosphate with 60HAp:40?-TCP granules was the best, whereas that of the pure HAp was the worst. To this end, it can be concluded that the calcium phosphate with moderate biodegradability is good for producing good osteoconductivity.