Being a sophisticated process, the electrochemical behavior of dental alloys relies on a lot of factors such as surface treatment, environment-related conditions around the alloys, the composition and structure of the alloys. Metallic materials used in medicine and dentistry should be very resistant to corrosion and not cause any biological response. The aim of this study was the evaluation of influence of TiN monolayer, CrN monolayer and TiN/CrN multilayer on hardness properties (micro and nano-indentation), surface roughness, corrosion resistance and ion release from nickel chromium dental alloy in artificial saliva environment with different pH levels (3, 4, 5, 6.5 and 8).The samples of Ni-Cr dental alloys were produced by lost-wax technique and the TiN, CrN and TiN/CrN nano-layer coatings were deposited by means of cathodic arc evaporation method (CAE-PVD). The surface roughness of the alloys was investigated by (Profilometer and AFM device). The EDS, and XRD were also used in the study for analyzing the distribution of elements on the surface and cross- section of coated and uncoated Ni-Cr specimens and to investigate crystal structure, type, and orientation, as well as the boundaries between crystals. It is also used to assess the effect of alloying elements on phase formation and distribution. The tribological tests were performed in artificial saliva so that wear factor and the friction coefficient can be determined. The corrosion behavior of coatings was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The microstructure characterizations and composition of selected alloys were done before and after electrochemical test in artificial saliva, using scanning electron microscopy (SEM). The results showed when tested surface roughness, a coating procedure has given different results among them as some of them gave higher roughness of the surface (TiN and TiN/CrN) samples while some other low of the surface roughness
