This paper reports the effect of the various ceramic coatings viz., hydroxyapatite (HA) and partially stabilized zirconia (PSZ) on the bond strength between the bone and implant, and cell compatibility of screw-shaped Ti-6Al-7Nb dental implants. Electrophoretic deposition technique (EPD) was used to obtain a uniform coating of one of the three types of ceramic layers (HA, PSZ and 50%HA + 50%PSZ) on the screws. Structural investigations were carried out on the prepared HA powder and the modified surfaces of the Ti-6Al-7Nb alloy using different techniques, namely X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The in vivo studies were performed by the implantation of screw-shaped uncoated and coated implants in the tibia of white New Zealand rabbits. To understand the bone-implant interface, biomechanical test was carried out after 2, 6 and 18 weeks healing periods. There was increased mechanical strength (torque value) of bone-implant interface with time, and the highest increment in the bond strength was recorded for implants coated with a 50% HA and 50% PSZ. Histological results show that the coated Ti-6Al-7Nb screws after 18 weeks of the implantation seem to be well-tolerated by the bone since no adverse tissue reaction was evident. However, there was a faster reaction of bone towards the coated implants compared to the uncoated one. The histochemical stain studies shows higher cellular activity and mature bone formation on all the samples.

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The composite coating is used to protect carbon steel pipeline from corrosion by Surfacemodification using thermal spraying technique to enhance the corrosion resistance of carbonsteel. In this study the influence of sour hydrocarbon on carbon steel was investigated onsamples taken from Alloys with (API 5L) that used for oil transport pipe lines in North OilCompany in Kirkuk fields and specifically from well (No. K-130) which the oil sample wasbrought as well. The cermets coating (Ni-Al /ZrO2-8Y2O3) were prepared in different mixingratios of Yttria-Stabilized Zirconia (YSZ) with Ni-Al as a self-bonding. Several mixing ratios ofthe binder (Ni-Al) were used to prepare the cermets for thermal spraying coating namely 15%and 50%. In order to study the effect of roughness on the binding of the cermets and hence thecorrosion behavior of the carbon steel another specimen was mechanically abraded to a surfacefinish 800 grit by SiC paper and the cermets mixing ratio (50% YSZ+ 50% Ni-Al) .The thermalspraying gun was located in an angle of 90º in front of the carbon steel specimen and the distancebetween them was 16 cm. The corrosion behavior of the modified surface in comparison withuntreated one was investigated by electrochemical techniques. Two electrochemical techniques(DC and AC techniques) were used. The AC technique was potentiodynamic cyclic polarizationusing Solatron 1287, USA) potentiostat/galvanostate. The EIS measurements for all coatedspecimens show enhancement in the impedance parameters (total impedance |Z|, polarizationresistance (Rp) and the capacitance (C)) comparing to the uncoated one. The cermets thermallysprayed coating show improvement in the corrosion parameters.