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

Abstract

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 5~20Mg/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 Ecorr and higher Icorr compared to the HA film surface without Si and Mg ions. And the Ipp and I300 for 5~20Mg/5Si formed on the Ti-6Al-4V alloy were lower than those of the surface coated with HA without Si and Mg ions.