Studies on Development, Bioactivity and Corrosion Behaviour of Nanostructured Titania/Hydroxyapatite Composite Layer on Cp Ti

Abstract

Nanostructured titania/hydroxyapatite (HA) composite layer was developed on commercially pure titanium (Cp Ti) implant material by plasma electrolytic processing (PEP) technique in order to improve its bioactivity and corrosion resistance under physiological conditions. The phases present in the developed composite layer were studied by X-ray diffraction (XRD) technique. The surface morphology and thickness of the composite layers were observed by scanning electron microscopy (SEM). The corrosion characteristics of the developed layer were studied by potentiodynamic polarization scan under simulated body fluid (7.4 pH Hanks solution) and simulated osteoclast (4.5 pH) conditions. The in-vitro bioactivity of the composite layers was studied by using Kokubu’s simulated body fluid (SBF) solution. The X-ray diffractograms reveal the presence of anatase TiO2 and HA phases in the developed layer. The SEM results confirm the pore-free morphology of the implant material surface and the thickness of the developed composite layer was observed to be 110 ± 5 µm for 12 min of PEP. The potentiodynamic polarization study shows an improved corrosion resistance and the in-vitro bioactivity test results indicate enhanced apatite forming ability of PEP treated Cp Ti surfaces compared to that of the untreated Cp Ti, under simulated body fluid conditions.