BCP coatings on pure titanium plates by CD method

Ca–P coatings on pure titanium plates were precipitated in this work by a cathode deposition (CD) method and showed several differences from other reported works. The fast calcification solution (FCS) and revised simulation body fluid (R-SBF) were used as electrolytes. A significant difference in sizes of crystals and thickness of the precipitated coatings was observed between the bioactive calcium phosphate (BCP) coatings precipitated from FCS and from R-SBF. The possible reason of this difference was ascribed to that the ion concentrations of Ca2+ and HPO42− and some inhibitors of Ca–P crystals growth such as Mg2+ and CO32− ions and pH of electrolytes. The crystalline structure and composition of BCP coatings are of special importance to applications of the BCP coatings. The characterization has been fulfilled by the use of XRD, FTIR, SEM and TEM. The results of this study made it clear that the precipitates on the Ti plates by cathode deposition method in different electrolytes were not the hydroxyapatite (HA) but octacalcium phosphate (OCP) and some carbonate-containing amorphous calcium phosphate apatite, and a few of precipitates changed to needle-like HA after immerged in a 0.1 M NaOH solution at 60 °C for 48 h. The present study confirms that CD method is a more convenient and fast way to prepare BCP coatings on titanium implants than the reported works.