Preparation and characterization of hydroxyapatite/titania nanocomposite coatings on titanium by electrophoretic deposition

Hydroxyapatite (HA)/titania nanocomposite coatings with varied compositions were fabricated by electrophoretic deposition (EPD) method on titanium substrates. The EPD kinetics decreased more prominently with time in case of suspensions with higher amount of titania nanoparticles. The cracking induced by sintering decreased and finally completely disappeared by increasing the titania content in the suspensions (>= 50 wt%). The adhesion strength of coatings also increased with titania content in suspensions. Cell culture experiments showed that the coating deposited from the suspension with 50 wt% of titania nanoparticles has the highest cell growth efficiency. Considering the results obtained by microstructural (crack formation), adhesion and cell culture analysis, the coating deposited from the suspension with 50 wt% of titania nanoparticles was regarded as the optimum. The optimum coating showed high bioactivity and its surface covered completely with thick apatite layer after soaking in simulated body fluid (SBF) for 1 week. The application of optimum coating on the titanium substrate considerably decreased its corrosion rate in SBF.