Influence of zirconia on biomimetic apatite formation in pure titanium coated via plasma electrolytic oxidation

This work demonstrated the effect of zirconia incorporation on the formation of biomimetic apatite in pure titanium coated by plasma electrolytic oxidation (PEO) method. To incorporate zirconia particles into the oxide layer, electrochemical coating was carried out under AC condition in an electrolyte containing zirconia powder. After PEO coatings, zirconia particles were distributed uniformly throughout the titanium oxide layer while the size and distribution of micro-pores remained unchanged when compared to titanium coated by PEO in an electrolyte without zirconia. It was found that a number of fine zirconia particles played an important role in triggering the occurrence of biomimetic apatite on top of the PEO-coated titanium in a simulated body fluid solution. This was mainly attributed to increased surface roughness of the oxide layer as well as inherent activation of zirconia particles to form biomimetic apatite.