Use of PVA to Improve Adhesion of CaP Coating on Titanium Implants

Calcium phosphate (CaP) ceramic coatings are widely used to improve the bioactivity of titanium implants in dental and orthopedic surgical treatments. In this study, CaP coatings produced on titanium alloy were synthesized by galvanostatic deposition at various current densities (2.5, 5, 7.5 mA/cm 2) in 1,05 mM Ca(NO3)2 and 0,625 mM NH 4H2PO4 solution with 0.0125 and 0.05 vol. % of poly vinyl alcohol (PVA) addition at 80 °C. Poly vinyl alcohol (PVA) was added in electrolyte in order to improve the adhesion between coating and titanium substrate. The surface morphology and chemical composition of the coatings were characterized by using scanning electron microscopy (SEM), X-ray diffractometry (XRD) and fourier transform infrared spectra (FTIR). Adhesion of deposited layers onto the substrate was investigated by using scanning scratch tester. In all the coatings produced, it was found that the phases formed are HAP and independent of PVA addition. Coating deposits under conditions of 7.5 mA/cm2 current density in electrolyte with 0.05 vol. % of PVA addition was found to have the best adhesion to the substrate among the coatings. © 2009 Springer Berlin Heidelberg