Surface Characteristics of Dental Implant Doped with Si, Mg, Ca, and P Ions via Plasma Electrolytic Oxidation

The surface characteristics of a dental implant doped with Si, Mg, Ca, and P ions via plasma electrolytic oxidation (PEO) were investigated using various experimental instruments. Plasma electrolytic oxidation of the alloy was performed in a solution containing Ca, P, Si, and Mg ions at 280 V for 3 min. The potentiodynamic polarization test of the porous surface was conducted in a 0.9% NaCl solution. The Si and Mg ion-doped HA films exhibited small and large micro-pores with uniform distributions after the PEO treatment. The micro-pores formed on the 5 similar to 20Mg/5Si coated samples were smaller than those on the Si and Mg ion-free CaP coated surfaces, as the Mg ion concentration increased. The XRD peaks of Si, Mg, Ca, and P appeared and the Si, Mg, Ca, and P were well distributed on the PEO-treated surface, especially on the top, valley and crest of the screw. The Ca/P ratio decreased as Mg content increased in the electrolyte. The diffraction peak of anatase TiO2 was observed on the Si and Mg ion HA film formed on the Ti-6Al-4V alloy. The adhesion force of the Si and Mg doped HA films increased with increasing Mg and Si ion concentrations. A passive region due to passive film formation was observed. The HA film surface with Si and Mg ions showed lower E-corr. and higher I-corr compared to the HA film surface without Si and Mg ions. And the I-pp and I-300 for 5 similar to 20Mg/5Si formed on the Ti-6Al-4V alloy were lower than those of the surface coated with HA without Si and Mg ions.