Synthesis and characterization of calcium phosphate coatings on ZrO2 ceramics for bone implant applications

Calcium phosphate (Ca-P) coatings on zirconia bone implants have a great potential to improve the osseointegration of already existing ceramic implants, owing to their bone-bonding ability and high osteoconductive characteristics. In our study, we have prepared three different kinds of Ca-P coatings, namely the octacalcium phosphate (OCP), hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) coatings. The OCP coatings were prepared by utilizing a simple wet-chemical biomimetic procedure, which included immersion of the implant material in a solution with a similar composition as the human blood plasma and at physiological conditions. Further heat treatment of the OCP coatings at 600 oC and 800 oC resulted in the formation of HAp and β-TCP coating, respectively. Beside the changes in the morphology and crystal structure, the heat treatment also improved the adhesion of the coating to the ceramic substrate.