A method for the plasma electrolytic oxidation of a bioactive coating onto implant (4) is provided. The implant is placed in an electrolyte solution (3) providing Ca and P ions and then connected to a power supply (1). A counter electrode is also provided in the electrolyte solution. A sequence of voltage pulses having alternating polarity are then applied across the implant and counter electrode to deposit a bioactive coating onto the implant. A intra-bone implant formed by the method is also provided having a coating with a thickness of 10 to 30 microns, a porosity comprised by pores with sizes of 0.5 to 10 microns, and comprising 10 to 30 wt % of hydroxyapatites.