An Ultrasound-assisted Method on the Formation of Nanocrystalline Fluorohydroxyapatite Coatings on Titanium Scaffold by Dip Coating Process

In this study, titanium scaffolds with porosity of 60 volume percent were produced by Ti powder and urea space holder, using powder metallurgy technique. Dip-coating sol-gel process was used to coat titanium scaffolds with fluorohydroxyapatite (FHA) ceramics in order to improve their osteointegration for medical implant purposes. Scanning electron microscopy (SEM) with energy dispersive spectrometers (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray diffraction (XRD) were employed to ensure removal of urea particles, non-oxidized samples caused by sintering process as well as evaluation of nanocrystalline fluorohydroxyapatite coating structure. Results implied that ultrasonic irradiation could promote transferring of coating slurry into the pores and using a low temperature process improve crystallization and decreases the crystallite size of fluorohydroxyapatite to about 50 nm. Moreover, ICP-OES analysis indicated that Ca:P molar ratio was 1.69, which was quite close to the molar ratios of the natural bone calcium and phosphor elements.