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Shining a Light on Amalgam Fillings

Mercury is one of the most toxic nonradioactive materials known to humankind. Yet, mercury constitutes 50% of dental amalgam fillings (1). Amalgam fillings (deceptively marketed as “silver fillings”) is a metal alloy made up of mercury, tin, silver, copper and traces of other metals. Shockingly, many dentists in the U.S. today still place amalgam fillings as a low-cost restorative solution. However, many countries, such as Denmark, Japan, Norway, Russia, and Sweden have already banned the use of amalgam fillings, while many other countries have begun the phase out process.


The US Food and Drug Administration (FDA), since 2020, and Health Canada, since the 1990s, have recommended the end of amalgam use for children and for pregnant women (2). On March 26th, 2022, at the 4th Conference of the Parties to the Minamata Convention on Mercury, a treaty of more than 130 nations, the Parties unanimously agreed to an amendment requiring countries to protect vulnerable populations from further use of dental amalgam: "…Exclude or not allow, by taking measures as appropriate, or recommend against the use of dental amalgam for the dental treatment of deciduous teeth [baby teeth], of patients under 15 years and of pregnant and breastfeeding women…" (3)


History

Metal fillings are believed to have first appeared in France in the early 1700s. Back then, if you had a cavity, the filling material was most likely a lead-based filling with gold and tin. The soft metal characteristics of lead made it viable to mold into the shape of a tooth. However, lead wore down more quickly, and gold became more expensive. It wasn’t until the 1800’s that the use of modern dental amalgam was adopted by replacing the lead with mercury, and gold with silver. Very little of the composition has changed in the last two hundred years.


In the two hundred years that amalgam fillings have been used, its safety has never been tested or proven in the United States by any regulatory agency. Under the 1976 Amendments to the Federal Food, Drug, and Cosmetics Act, Congress directed the FDA to assess the safety of medical and dental devices and to require premarket approval of safety for any device “intended to be implanted in the human body”, yet dental amalgam has been exempted by the FDA (4).


Mercury Toxicity

The constant release of mercury vapor from dental amalgam is absorbed into the blood through pulmonary airways and additionally through the tooth pulp or gingiva. Mercury has the ability to easily pass through the blood-brain barrier, and potentially cause neurological impairment (5). As the brain is a nearby target for mercury uptake, its bioaccumulation in the brain may be the cause for various neurological diseases such as multiple sclerosis, Parkinson and Alzheimer’s Diseases (6). Autism is related to high mercury levels, especially in children (7 & 8).


Mercury Bioaccumulation

Measuring mercury levels via blood or urine tests is difficult to associate with mercury toxicity due to mercury’s tendency to attach and accumulate in our tissue, rather than flowing through the blood. Autopsy studies have found 2 to 12 times more mercury in body tissues of individuals with dental amalgam (9). Autopsy studies have consistently shown many individuals with dental amalgam have toxic levels of mercury in their brains or kidneys (9).


Pregnant & Nursing Mothers

Due to the metabolization of body fat for energy during pregnancy and lactation, bioaccumulated mercury is released in the body and may travel to an unborn fetus and to the breast of lactating mothers. An autopsy study on deceased newborns and fetus has shown a direct correlation between dental amalgam fillings of the mother in pregnancy and the mercury levels in the body tissues of the babies or fetuses (9). An increasing number of maternal dental amalgam fillings correlates with increased fetal exposure in utero. Human placenta does not represent a real barrier to the transport of mercury (10 & 11).


Mercury in the Environment

The toxicity of dental amalgam goes far beyond our bodies from when we use the restroom, we are slowly releasing mercury laden sewage to our city treatment plants. These facilities either sell the sludge to farmers or truck it to landfills, where mercury pollutes and accumulates in our environment for centuries. Responsible dental offices do not release dental amalgam into the system sewer, as they have special amalgam separators installed that capture and contain the amalgam for safe disposal to an EPA approved site.


So, if many countries have already banned the use of dental amalgam, and the FDA now states that they should not be placed in children and pregnant women, how could we still think it is safe to have in our mouth?


Mercury Removal

The harm that dental amalgam causes to our bodies, and the environment is quite apparent. Safe removal of dental amalgam may not be as obvious. Removal of dental amalgam can pose significant health risks if not done correctly. The SMART protocol, as developed by the IAOMT (International Academy of Oral Medicine and Toxicology), is the most extensive protective protocol to safely removal dental amalgam. Only specially trained dentists who are SMART certified in dental amalgam removal should perform the procedure. You should observe the procedures listed by the IAOMT during your amalgam removal procedure.


References

1) U.S. Food & Drug Administration (FDA). Dental Amalgam Fillings. 18 February 2021. https://www.fda.gov/medical-devices/dental-devices/dental-amalgam-fillings. 2 May 2022.


2) Administration, U.S. Food & Drug. Recommendations About the Use of Dental Amalgam in Certain High-Risk Populations: FDA Safety Communication. 24 September 2020. https://www.fda.gov/medical-devices/safety-communications/recommendations-about-use-dental-amalgam-certain-high-risk-populations-fda-safety-communication. 5 May 2022.


3) American Broadcasting Company (ABC). Consumers for Dental Choice Salutes Worldwide Decision to Protect Children and Pregnant Women from Mercury Dental Fillings. 01 April 2022. https://www.abc27.com/business/press-releases/cision/20220401AQ11083/consumers-for-dental-choice-salutes-worldwide-decision-to-protect-children-and-pregnant-women-from-mercury-dental-fillings/. 25 April 2022.


4) U.S. Food & Drug Administration. Medical Device Exemptions 510(k) and GMP Requirements. 2 May 2022. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpcd/315.cfm?GMPPart=872. 04 May 2022.


5) Ertas, E. et al. "Human brain mercury levels related to exposure to amalgam fillings." Human and Experimental Toxicology (2014): 874. DOI: 10.1177/0960327113509662.


6) Bjorklund, Geir. "Metals and Parkinson's Disease: Mechanisms and Biochemical Processes." Current Medicinal Chemistry Vol. 25,19 2018: 2198-2214. doi:10.2174/0929867325666171129124616.


7) Jafari, T et al. "The association between mercury levels and autism spectrum disorders: A systematic review and meta-analysis." Journal of trace elements in medicine and biology: organ of the Society for Minerals and Trace Elements (GMS) Vol. 37 2017: 289-297. doi:10.1016/j.jtemb.2017.09.002.


8) Kern, Janet et al. "The relationship between mercury and autism: A comprehensive review and discussion." Journal of Trace elements in medicine and biology: organ of the Society for Minerals and Trace Elements (GMS) Vol. 37 2016: 8-24. doi:10.1016/j.jtemb.2016.06.002.


9) Mutter, Joachim. "Is Dental Amalgam Safe for Humans? The Opinion of the Scientific Committee of the European Commission." Journal of Occupational Medicine and Toxicology (2011). https://doi.org/10.1186/1745-6673-6-2.


10) Ask, Karolin et al. "Inorganic mercury and methylmercury in placentas of Swedish women." Environmental Health Perspective Vol. 110,5 May 2002: 523-526. doi:10.1289/ehp.02110523.


11) Palkovicova, L et al. "Maternal amalgam dental fillings as the source of mercury exposure in developing fetus and newborn." Journal of Exposure Science & Environmental Epidemiology Vol. 18,3 (2008): 326-31. doi:10.1038/sj.jes.7500606.