Korean J Dent Mater.  2021 Dec;48(4):255-268. 10.14815/kjdm.2021.48.4.255.

Plasma electrolytic oxidized surface of (Mg/Si)-hydroxyapatite coated Ti-29Nb-xHf alloys for dental implant

• Park SY
• Choe HC

• KMID: 2524541
• DOI: http://doi.org/10.14815/kjdm.2021.48.4.255

Abstract

In this study, in order to form a micropore oxide film containing (Mg/Si)-hydroxyapatite on the surface of a Ti-29Nb-xHf alloy, pores were formed on the surface of the alloy by plasma electrolytic oxidation (PEO) and the morphology of the surface was studied. For this, Ti-29Nb, Ti-29Nb-3Hf, Ti-29Nb-7Hf, and Ti-29Nb-15Hf alloys were prepared by arc melting. Micropores were formed on the surface in an electrolyte solution containing Mg and Si ions using PEO. Surface characteristics and mechanical properties of all specimens were investigated using OM, FE-SEM, XRD, EDS, Vickers hardness and nanoindenter. Bone formation was performed in SBF solution, and the following results were obtained. Ti-29Nb, Ti-29Nb-3Hf, and Ti-29Nb-7Hf showed mainly needle-like martensitic structures, and Ti-29Nb-15Hf alloys showed mainly equiaxed structures. From the result of the mechanical property analysis, the elastic modulus and hardness of the Ti-29Nb alloy decreased, as the Hf content increased. Under the condition of same applied voltage, as the content of Mg ions increased, the diameter of the micropores became smaller and uniform pores were formed. The Ca/P and (Ca+Mg)/(Si+P) ratios decreased, as the Mg content increased, and at 5% Mg, the ratio was similar to that of natural bone. Bone growth was nucleated around the pore.

Keyword

Ti-29Nb-xHf alloy; Plasma electrolytic oxidation; Martensite; Elastic modulus