Preparation and properties of plasma electrolytic oxidation coating on sandblasted pure titanium by a combination treatment

• Combination treatment deposits Ca- and P-containing coating on pure titanium.
• Oxide coating is produced on sandblasted substrate in (CH3COO)2Ca·H2O and C3H7Na2O6P·5H2O electrolytes.
• Combination-treated coating exhibits better mechanical properties and bioactivity.
• Nano-structure hydroxyapatite forms on combination-treated coating.

Plasma electrolytic oxidation (PEO) is one of the most applicable methods to produce bioceramic coating on a dental implant and sandblasting is a primary technique to modify metal surface properties. This study aims to deposit bioceramic Ca- and P-containing coatings on sandblasted commercially pure titanium by PEO technique to improve its bioactive performance. The time-dependent modified surfaces are characterized in terms of their microstructure, phase, chemical composition, mechanical properties and bioactivities. The results show that the combination-treated coating exhibits better properties than the PEO-treated one, especially in bioactivities, as evidenced by the HA formation after immersion in simulated body fluid (SBF) for 5 days and the cell viability after seeding for 1 or 3 days. The enhancement of the modified surface is attributed to a combination of the mechanical sandblasting and the microplasma oxidation.