In 2004, there were some reports that the regulation for all post assemblies which are inserted into pierced ears and other pierced parts of the human body unless the rate of nickel release from such post-assemblies is less than 0.2 mg/cm2/week. The direct and prolonged contact with the skin, 12.8 % of decorative parts and 17.1 % of clasps exceeded the migration limit [4,5].