Amalgam (dentistry) - Dental Amalgam Toxicity Controversy

Dental Amalgam Toxicity Controversy

Controversy over the mercury component of dental amalgam dates back to its inception, when it was opposed by the United States dental establishment, but it became a prominent debate in the late 20th century, with consumer and regulatory pressure to eliminate it "at an all-time high". Many people are unaware of the mercury in fillings, and this lack of informed consent was the most consistent issue raised in a recent U.S. Food and Drug Administration panel on the issue by panel members. Environmental concerns over external costs exist as well, as the use of dental amalgam is unregulated at the federal level in, for example, the United States. The WHO reports that mercury from amalgam accounts for 5% of total mercury emissions and that when combined with waste mercury from laboratory and medical devices, represents 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. As of 2008, the use of dental amalgam has been banned in Norway, Sweden and Denmark, and a committee of the US Food and Drug Administration (FDA) has refused to ratify assertions of safety.

In the 1990s, several governments evaluated the effects of dental amalgam and concluded that the most likely health effects would be due to hypersensitivity or allergy. Germany, Austria, and Canada recommended against placing amalgam in certain individuals such as pregnant women, children, those with renal dysfunction, and those with an allergy to metals. In 2004, the Life Sciences Research Office analyzed studies related to dental amalgam published after 1996. Concluding that mean urinary mercury concentration (μg of Hg/L in urine, HgU) was the most reliable estimate of mercury exposure, it found those with dental amalgam were unlikely to reach the levels where adverse effects are seen from occupational exposure (35 μg HgU). 95% of study participants had μg HgU below 4-5. Chewing gum, particularly for nicotine, along with more amalgam, seemed to pose the greatest risk of increasing exposure; one gum-chewer had 24.8 μg HgU. However, from reviewing medical literature, the World Health Organization states mercury levels in biomarkers such as urine, blood, or hair do not represent levels in critical organs and tissues. Additionally, Gattineni et al. found that mercury levels do not correlate with the number or severity of symptoms. It concluded that there was not enough evidence to support or refute many of the other claims such as increased risk of autoimmune disorders, but stated that the broad and nonspecific illness attributed to dental amalgam is not supported by the data. Mutter in Germany, however, concludes that "removal of dental amalgam leads to permanent improvement of various chronic complaints in a relevant number of patients in various trials."

There is strong evidence that a certain percentage of lichenoid lesions are caused by amalgam fillings.