What is dental amalgam?
Dental amalgam is a tooth filling material that is approximately 50% mercury. It is sometimes misleadingly called a “silver filling”, even though it contains far more mercury than silver. Mercury, a heavy metal, is known to be poisonous to the human nervous system.
There are still dentists out there who use this toxic mercury product, so make sure to say “No amalgam!” before you ever sit in that dental chair. Ask for mercury-free fillings instead!
Health Risks Associated with Amalgam
When it comes to your health, amalgam can do far more harm than good....
Dental amalgam is approximately 50% mercury, a known neurotoxin and reproductive toxin. Amalgam releases mercury vapors throughout its lifecycle, especially when
- the dentist places the amalgam in your tooth
- you chew food or gum
- you brush your teeth
- you grind your teeth
As a result, people with amalgam fillings have higher levels of mercury in their bodies than people without amalgam fillings.
Mercury exposure from dental amalgam is not safe for anyone. But it is particularly risky for....
- Children: Children’s developing brains and neurological systems are particularly susceptible to the neurotoxic effects of amalgam’s mercury vapor. The U.S. Food and Drug Administration (FDA) admits that there is no evidence that amalgam is safe for children: “Very limited to no clinical information is available regarding long-term health outcomes in pregnant women and their developing fetuses, and children under the age of six, including infants who are breastfed.” Many countries – including the entire European Union – are banning amalgam use in children.
- Women of childbearing age: Mercury from a mother’s amalgams can cross the placenta and accumulate in her unborn child. As mentioned above, the FDA admits that there is no evidence that amalgam is safe for developing fetuses. Many countries – including the entire European Union, Canada, Australia, and Mauritius – are banning or recommending against amalgam use in pregnant women.
- Breastfeeding infants: Mercury from a mother’s amalgams can be passed to her infant through breast milk. The European Union is banning amalgam use in breastfeeding mothers.
- People with kidney impairments: Mercury can be harmful to your kidneys, especially if you already have a kidney disorder. Decreased kidney function (decreased renal clesarance) is likely to decrease the body’s ability to eliminate mercury via urine. Canada warns against the use of amalgam in people with kidney impairments.
- Genetically-susceptible individuals: Recent studies found that some individuals are more genetically prone to suffer the neurotoxic effects of mercury from amalgam. For example, Woods et. al. (2012) found “significant adverse effects on neurobehavioral functions associated with chronic Hg [mercury] exposure [from amalgam] and the CPOX4 genetic variant among children, with effects manifested predominantly among boys.”
- People with pre-existing neurological problems: Mercury is known as a potent poison of the brain and nervous system. If you already have a neurological problem, it would be risky to add neurotoxic mercury from amalgam on top of it.
- People already exposed to other mercury sources: Mercury from amalgam and other sources (like some fish) is bioaccumulative, meaning that it builds up in increasing concentrations in the body. If you are already exposed to mercury in your workplace or diet, the additional mercury from amalgam is likely to be more than your body can handle.
- People with allergies or hypersensitivities: The FDA warns against use of amalgam in people with allergies or hypersensitivities to mercury. As FDA’s rule explains, “FDA concludes that existing data indicate that certain individuals with a pre-existing hypersensitivity or allergy to mercury may be at risk for adverse health effects from mercury vapor released from dental amalgam.... FDA concluded that various dermatological conditions or lesions of the skin, mouth, and tongue were attributed to direct or indirect contact with dental amalgam, and may have been related to a pre-existing hypersensitivity or allergy to mercury and/or other metals.”
- People with other metals in their mouth: The FDA warns against use of amalgam when it would come into direct contact with other metals in the mouth, such as stainless steel, titanium, base metal alloys, and noble metal alloys. As FDA’s rule explains, “Dental amalgam devices may corrode under certain conditions, including when they are placed in direct contact with other metals. If a dental amalgam device corrodes, it will lose its strength and will need to be replaced. Corrosion also increases the amount of mercury vapor a dental amalgam device releases.” So if you’ve got braces, beware!
- Dental professionals: In addition to their direct contact with mercury, dental professionals who work in offices that use amalgam also face high levels of mercury in the air they breathe. As a result, dental professionals – including dentists, dental hygienists, dental assistants, and office staff – are at particular risk. Studies have shown that they have elevated systemic mercury levels. Since many dental professionals are women of child-bearing age, they are especially susceptible to the reproductive hazards associated with mercury exposure.
Tooth Damage Associated with Amalgam
On top of the risks of mercury exposure, amalgam is not even good for teeth.
Oral health damage
Amalgam can harm your oral health by....
- Damaging tooth structure during placement: Placing amalgam requires the removal of a significant amount of healthy tooth matter.This removal weakens overall tooth structure, which increases the need for future dental work – and the costs coming out of your pocket.
- Cracking teeth after placement: After placement, amalgam fillings expand and contract over time. As a result, these teeth can crack – leading to still more dental work.
Superior modern alternatives to amalgam preserve healthy tooth structure and actually strengthen teeth, leading to better oral health and less extensive dental work over the long-term.
Environmental Problems Associated with Amalgam
Mercury amalgam dental fillings have an impact far beyond your mouth – they are one of the most significant sources of mercury pollution today.
Quantity of dental mercury
Between 270 and 341 tonnes of mercury are consumed globally for use in amalgam each year. Accounting for at least 10% of global mercury consumption, amalgam is among the largest consumer uses of mercury in the world.
Pathways to the environment
Dental mercury enters the environment via many different pathways. For example, dental mercury pollutes:
- Air via human cremation, sewage sludge and waste incineration, and dental clinic emissions
- Water via human waste disposal and dental clinic releases
- Land via landfills, human burials, and fertilizers
Environmental health risks
After amalgam enters the environment, certain microorganisms can change its elemental mercury into methylmercury, a highly toxic form of mercury that builds up in fish, shellfish, and people that eat fish. Methylmercury can damage children’s developing brains and nervous systems even before they are born
After environmental costs are taken into account, amalgam is significantly more expensive than the mercury-free fillings. According to the 2012 report The Real Cost of Dental Mercury, an amalgam filling can cost up to $87 (USD) more than an equivalent mercury-free composite filling, once the full lifecycle costs of each filling is taken into account.
The Minamata Convention on Mercury is a global treaty to protect human health and the environment from the adverse effects of mercury. The Convention requires each party to “phase down the use of dental amalgam.” It also addresses amalgam in Annex A, where it can be amended later to set a phase-out date for this toxic mercury product. The United States government has signed this Convention, but so far taken no step to effectively phase down amalgam use.
Workplace Hazards Associated with Amalgam
Dental professionals face the hazards of amalgam’s mercury everyday in their workplace, most of them with no protection against mercury exposure....
Workplace mercury exposure
Dental professionals – including dentists, dental hygienists, dental assistants, and dental office staff – can be exposed to mercury in their workplace, both directly and indirectly:
- Direct exposure: Dental professionals can come into direct contact with amalgam’s mercury during the preparation, placement, and removal of amalgam fillings. Accidental mercury spills can also lead to direct exposure.
- Indirect mercury exposure: Dental professionals can also encounter mercury indirectly in their work environment. Researchers have found high levels of mercury in the air of dental offices that use amalgam. This mercury can also contaminate carpeting and pipes.
Workplace health problems
This exposure to mercury in the workplace would explain....
- Higher mercury levels in dental professionals: Dental workers have higher levels of mercury in their bodies than the general population.
- More health problems for dental professionals: Dentists report or seek treatment for more health problems – including neurological, neuropsychological, respiratory, cardiac, and kidney disorders – than the general population.
- Reproductive problems for female dental professionals: : Female dental professionals of child-bearing age who are exposed to amalgam in the workplace experience more reproductive problems than unexposed women.
Social Injustices Associated with Amalgam
The use of mercury amalgam has led to many social injustices, including....
The term “silver fillings” has misled many dental consumers into believing that amalgam is just silver when it is really mostly mercury. Only 11% of Americans are told by their dentists that amalgam fillings are 50% mercury – and Americans making under $50,000/year, racial minorities, and women are even less likely to get enough information about what’s in their dental fillings. Consumers for Dental Choice is leading the charge to expose the “silver fillings” deception. Learn more here.
Amalgam is routinely used in people who are given no choice – especially low-income families, soldiers, veterans, American Indians, and others subject to government dental programs through Medicaid/Medicare, the Department of Defense, Department of Veterans Affairs, and the Indian Health Service. Consumers for Dental Choice is challenging government programs that deny people the choice of mercury-free fillings. Learn more here.
Many dental insurance companies will not fully pay for mercury-free dental fillings. Instead, they give preference to mercury amalgam fillings, which they fully pay for. Consumers for Dental Choice is leading the campaign to reform insurance coverage to include mercury-free fillings. Learn more here.
Mercury-free filling options
Mercury-free dental fillings have been developed and studied for over fifty years. As a result, a wide variety of alternatives to mercury amalgam fillings are available today. The most popular mercury-free fillings include:
- Glass Ionomer
Advantages of mercury-free fillings
Mercury-free dental fillings offer many advantages:
- Environment-friendly: Composites and glass ionomers are mercury-free, and there is no evidence of environmental toxicity.
- Preserve teeth: The placement of mercury-free fillings allows for less tooth destruction, which preserves more natural tooth structure. Composites fillings can also strengthen and enhance biomechanical properties of the restored tooth. As a result, the tooth itself can survive longer.
- Easier to Repair: Composite fillings are easier to repair than composites – which can save you both tooth structure and money.
- Durable: Recent studies show that properly placed composite fillings can last just as long as– or even longer than – amalgam fillings.
- Prevent caries: Glass ionomers, used in atraumatic restorative treatment (ART), have proven valuable in certain clinical situations where they can be more accessible and less expensive than amalgam (for example, in communities without electricity).
- User-friendly: All properly trained dentists can place mercury-free fillings in any tooth requiring a filling. If a dentist tells you he or she has to use amalgam because it is too hard to use a mercury-free filling in your tooth, find a more competent dentist!
Increasing use of mercury-free fillings
Because mercury-free dental restorations are increasingly effective, available, and affordable, a growing number of countries have already made significant progress in phasing down – and even phasing out – amalgam use. The chart below shows the percentage of total fillings that are amalgam versus how many are mercury-free in several countries.