The Benefits and Risks of Dental Amalgam

What Do The Experts Say?

Dental Amalgam

 

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The controversy surrounding the safety of dental amalgam fillings has been going on for decades. While still the matter of debate, the U.S. Food and Drug Administration (FDA), the American Dental Association (ADA) and other health authorities continue to assert it is safe to use. Learn what recent studies say and why some are concerned about dental amalgam.

What Is Dental Amalgam?

Dental amalgam is the silver material used by the dentist to fill teeth after tooth decay is removed. Amalgam, comprised of a mixture of silver, tin, and copper—along with mercury—has been a primary material for dental use for over 150 years.  Dental amalgam is often referred to as a silver tooth filling because of the color of the filling material.

The safety of the mercury component of dental amalgam has been the subject of much argument for many years. The research on the safety of the level of mercury—a toxic substance—on many of the body’s organs (such as the kidneys, the brain and more) differs, depending on which source a person is considering. In the past, the consensus was that all dental amalgam fillings caused toxicity to the nervous system and other organs and should be replaced by a safer dental filling material. But, today, many expert sources of information, such as the U.S. Food and Drug Administration, tell a different story. So, why are amalgam fillings used and what does the research say? Are dental amalgam fillings safe?  

The Benefits of Dental Amalgam

Amalgam fillings are considered an effective way to stop dental decay and replace the area of a tooth that has been destroyed by dental caries (cavities). Amalgam is very hard when it dries, it is long-lasting and more cost-effective than many other types of dental filling materials (such as polymer filling material). 

Risks of Amalgam Fillings

Mercury Vapor

There are reported risks of the use of amalgam due to its mercury component. Mercury has been found to release a type of vapor that can be inhaled into the lungs and then travel to various parts of the body (possibly causing adverse effects in organs such as the kidneys and the brain).

But, the FDA considers dental amalgam fillings “’safe for adults and children ages 6 and above.”  The FDA warns that in pregnant women and children under age 6—including infants who are breastfeeding—there has not been enough reliable research studies to show the long-term effects of amalgam fillings. However, the FDA reports, “The existing risk information supports a finding that infants are not at risk for adverse health effects from the mercury in breast milk of women exposed to mercury vapor from dental amalgam.”

Bioaccumulation

The steady accumulation of a chemical in the tissues or organs of the human body is called “bioaccumulation.” This process is thought to occur as a result of mercury in amalgam fillings. Although the type of mercury in fillings differs from that found in fish, this bioaccumulative process also occurs from mercury-poisoned seafood. The FDA reports that exposure to mercury vapor may accumulate in certain tissue in the body, such as the kidneys and the brain. But, there has not been sufficient evidence to prove that organ damage results from this build-up of mercury.

Allergies

Some people are allergic to components in amalgam fillings, such as mercury, copper, silver, or tin. An allergic reaction may result in oral lesions (sores in the mouth) or other reactions. Those who have reactions to amalgam fillings are encouraged to discuss alternative options (other than amalgam) for dental filling material.

Recent Studies

Much of the clinical research data shows mixed results. For example, a 2012 review of studies published in medical journals, as well as reports from organizations such as the World Health Organization (WHO), discovered that the use of amalgam “has not posed a health risk apart from allergic reactions in few patients.” The study authors went on to explain that there were no clinical findings to support the theory that dental amalgam fillings should be replaced. “There is no evidence that mercury released from amalgam results in adverse health effects in the general population. If the recommended mercury hygiene procedures are followed, the risks of adverse health effects in the dental office could be minimized. Amalgam is safe and effective restorative material,” said the study authors.

A review by the American Dental Association states that: “Studies continue to support the position that dental amalgam is a safe restorative option for both children and adults. When responding to safety concerns it is important to make the distinction between known and hypothetical risks.”

“Dental amalgam is considered a safe, affordable and durable material that has been used to restore the teeth of more than 100 million Americans,” says the ADA.

But a 2019 review of the data, published by the International Journal of Environmental Research and Public Health, suggests that mercury exposure from dental amalgams may be associated with many maladies, including:

  • Neurological (the brain and nervous system) disease
  • Multiple sclerosis
  • Alzheimer’s disease (for those who are 65 or older with dental amalgams)

According to the study authors, New epidemiological studies are starting to emerge providing stronger evidence favoring a connection of dental amalgams with some neurological diseases. The data showed that Individuals exposed to amalgam fillings had a higher risk of Alzheimer’ s disease.”

A Word From Verywell

Although the FDA does not advise the public to replace amalgam fillings and explains that “Removing sound amalgam fillings results in unnecessary loss of healthy tooth structure, and exposes you to additional mercury vapor released during the removal process,” this information is not meant to be a substitute for your dentist’s advice. Before deciding on which type of filling material to select, it’s vital to discuss the issue with a dental professional. 

Those who believe they have an allergy to mercury (or other materials in amalgam fillings such as tin, silver or copper) may need to talk to a dental professional about alternative filling material.

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Article Sources

  1. U.S. Food and Drug Administration. Dental Amalgam. Updated December 5, 2017


  2. Rathore M, Singh A, Pant VA. The dental amalgam toxicity fear: a myth or actualityToxicol Int. 2012;19(2):81–88. doi:10.4103/0971-6580.97191


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