Metal alloys have been used extensively for long-lasting oral restorations.Because of the constant and long term contact with human tissue,corrosion and biocompatibility issues should be studied thoroughly in order to avoid the discomfort of patients(metallic taste)or the appearance of more serious problems such as allergies,oral lichen planus or oral lesions.The oral cavity is a perfect environment for the degradation of a metallic implant due to the permanent presence of factors that influence corrosion such as: saliva,changes of pH values,temperature fluctuations and mechanical stress.The multitude of factors brings difficulties in choosing a restauration material that can withstand the passage of time with minimum degradation.In recent years,there has been a special attention towards the use of Cobalt-Chromium alloys for metallic implants being comparable in terms of biocompatibility and mechanical resistance to Titanium alloys.