Dental amalgam controversy

The dental amalgam controversy is a debate over the use of mercury amalgam as a dental filling. The concern centers on the long-term health effects of toxicity or allergy which may be associated with constant mercury exposure, particularly as a potential cause of chronic illnesses, autoimmune disorders, neurodegenerative diseases, birth defects, oral lesions, and mental disorders. Scientists agree that mercury amalgam fillings expose the bearers to a daily dose of mercury, but different studies have concluded that this exposure may be as low as 1-3 µg/day (FDA), or as high as 27 µg/day (Patterson). The effects of this exposure are disputed, and currently dental amalgam is approved for use in most countries, although Norway and Sweden are notable exceptions.

A 2006 Zogby International poll of 2,590 US adults found that 72% of respondents were not aware that mercury was the main component of dental amalgam, and 92% of respondents would prefer to be told about mercury in dental amalgam before receiving it as a filling. A 1993 study published in FDA Consumer found that 50% of Americans believed mercury filings caused health problems. Some dentists, including one member of the FDA's Dental Products Panel, have suggested that the factors obligate dentists to apply the doctrine of informed consent by notifying their patients that amalgam contains mercury.

Dentists who advocate the use of amalgam point out that it is durable, cheap, and easy to use. On average, resin composites last only half as long as mercury amalgam, although more recent studies find them comparable to amalgam in durability, and dental porcelain is much more expensive. However, the gap between amalgam and composites may be closing. Further, concerns have been raised about the endocrine disrupting (in particular, estrogen-mimicking) effects of plastic chemicals such as Bisphenol A used in composite resins.

In addition to health and ethics issues, opponents to mercury amalgam fillings point to the negative externalities of water contamination and environmental damage of mercury, especially since its use by dentists goes largely unregulated in many places, including the United States. The WHO reports that mercury from amalgam and laboratory devices accounts for 53% of total mercury emissions.Separators may dramatically decrease the release of mercury into the public sewer system, where dental amalgams contribute one-third of the mercury waste, but they are not required in the United States.