Mechanical hydroxyapatite coatings on PEO-treated Ti–6Al–4V alloy for enhancing implant's surface bioactivity

Abstract

In this study, to reactivate the oxide film and to secure biocompatibility, plasma electrolytic oxidation (PEO) treatment and hydroxyapatite (HA) deposition via mechanical coating (MC) processes were investigated. This experimental approach involved subjecting the Ti–6Al–4V alloy specimens to PEO treatment, followed by MC with HA powder for different hours as HA has the potential to increase bioactivity and surface characteristics due to its chemical composition and structural properties similar to natural bone. Therefore, the study aimed to examine the effects of MC with HA powder for 0, 1, 3, 5, 7, and 9 h on PEO-coated Ti–6Al–4V alloy discs for analyzing the surface characterization, phase analysis, surface roughness, wettability, adhesion strength, hardness, corrosion behavior, and cell proliferation properties for dental implant use. The findings demonstrate that prolonged HA milling enhances the substrate's mechanical strength, corrosion resistance, and adhesion properties. The presence of prominent anatase and HA peaks, particularly in the 5 MC-PEO, 7MC-PEO, and 9 MC-PEO samples, validates the synergistic impact of the PEO oxide layer and HA milling, resulting in outstanding corrosion resistance and biocompatibility. Cell culture analysis reveals a positive correlation between increased milling time and enhanced cell proliferation, particularly towards small-sized HA particles.