Cytotoxicity due to corrosion of ear piercing studs

It is well known that allergic and/or inflammatory reactions fan be elicite d from the use of gold-coated studs, particularly the type used for piercin g cars, since they are left in contact with body fluids until the puncture heals. Inasmuch as gold is known as a non-toxic element, other elements of the substrate material may be responsible for some allergies. Therefore, ch aracteristics of the coating, such as defects that expose the substrate to the human skin or body fluids, play an important role in the development of skin sensitization. In this study, the cytotoxicity of commercial studs: u sed for ear piercing and laboratory-made studs was determined in a culture of mammalian cells. The corrosion performance of the studs was investigated by means of weight loss measurements and electrochemical impedance spectro scopy. The elements that leached out into the medium were also analysed by instrumental neutron activation analysis. Further, the surfaces of the stud s were examined by scanning electron microscopy and analysed bg energy disp ersive spectroscopy to identify defects and reaction products on the surfac e, both before and after their exposure to the culture medium. The stud whi ch showed lower corrosion performance resulted in higher cytotoxicity. Ti s howed no cytotoxicity and high corrosion resistance, proving to be a potent ial material for the manufacture of ear piercing studs. (C) 2000 Elsevier S cience Ltd. All rights reserved.