Behavior in simulated body fluid of calcium phosphate coatings obtained by laser ablation.

Three types of calcium phosphate coatings onto titanium alloy substrates, deposited by the laser ablation technique, were immersed in a simulated body fluid in order to determine their behavior in conditions similar to the human blood plasma. Neither the hydroxyapatite coating nor the amorphous calcium phosphate coating do dissolve and the alpha-tricalcium phosphate phase of the coating of beta-tricalcium phosphate with minor alpha phase slightly dissolves. Precipitation of an apatitic phase is favored onto the hydroxyapatite coating and onto the coating of beta-tricalcium phosphate with minor alpha phase. Onto the titanium alloy substrate reference there is also precipitation but at larger induction times. However, onto the amorphous calcium phosphate coating no precipitate is formed.