Electrodeposition of calcium phosphate coatings in polyvinyl alcohol

Brushite coatings were obtained on titanium by the method of electrochemical deposition from Ca(NO3)2/NH4H2PO4 electrolyte at Ca/P = 1.67, pH = 4 and a constant voltage of 15 V or a current density of 20 mA/cm2 for 20 min. In a medium of 0.01 – 0.10 % polyvinyl alcohol at a constant voltage of 15 V, are deposited single-phase brushite or monetite coatings are deposited. The addition of 0.01 – 0.10 % polyvinyl alcohol into the electrolyte during deposition at a constant current density of 20 mA/cm2 leads to the formation of composite calcium phosphate coatings containing brushite, calcium hydroxide and calcium phosphate of the apatite structure. The bioactivity of calcium phosphate coatings was confirmed by the formation of apatites during their soaking in the Simulated Body Fluid (SBF). Amorphized apatite formed on brushite coatings during 2 weeks soaking in SBF crystallizes into β-tricalcium phosphate after heat treatment. The apatite formed on the composite coating in the SBF crystallizes into a composition of hydroxyapatite and β-tricalcium phosphate. The resulting bioactive calcium phosphate coatings can be used as biocoatings to enhance osseointegration of titanium implants.