The usefulness of this precious element is derived from a diversity of special properties. Gold conducts electricity, does not tarnish, is very easy to work, can be drawn into wire, can be hammered into thin sheets, alloys with many other metals, can be melted and cast into highly detailed shapes.
Its main use is in industry and dentistry. Gold alloys are used for fillings, crowns, bridges, and orthodontic appliances. It has been used in dentistry for over 1000 years now. It is chemically inert, considered nonallergenic, and easy for the dentist to work.
Gold, in a variety of forms, has been used in medicine throughout the history of civilization. In the twentieth century gold complexes were introduced for the treatment for rheumatoid arthritis, culminating in the introduction of the oral drug Auranofin in 1985. The clinical use and mechanism of action of gold drugs is debated.
Gold is of low toxicity and gold drugs are slow acting, requiring long-term treatment. They often are administered by deep intramuscular injection at weekly intervals. After rapid absorption the gold is rapidly cleared from the bloodstream and distributed to various tissues including the kidneys where it accumulates and gives rise to nephrotoxicity, a major side effect. Other adverse reactions include mouth ulcers, skin reactions; blood disorders and occasional liver toxicity have been reported.
Blood testing only shows immediate exposure. Urine analysis provides information about renal clearance, and saliva testing reflects on the safety of dental gold.
S.P. Fricker, in 'Metal Ions in Biology and Medicine', ed. Ph. Collery, L.A Poirier, M. Manfait and j-C, Etienne John Libby Eurotext, Paris, 1990, p. 452
dto. Medical uses of gold compounds: present, past and future uses. Gold Bulletin 1996