What is dental amalgam?

Dental amalgam is a mixture of liquid mercury, silver, tin and copper that is used to repair teeth damaged by cavities. It contains 50% mercury by weight. Amalgam fillings are often called silver fillings because of their appearance.

Amalgams

Amalgam has been used in dentistry for more than 200 years because it is malleable and holds up well to wear and tear.

Is dental amalgam safe?

Numerous studies have been conducted over the years that support the use of amalgam for dental fillings. Organisations responsible for the public's health including the National Institutes of Health, World Health Organisation, United States Public Health Service and Food and Drug Administration, have affirmed that amalgam is a safe material to use in dental fillings.

Has dental amalgam been linked to other medical conditions?

Studies have failed to find any link between amalgam fillings and health disorders.

In 2004, the Life Sciences Research Office (LRSO) published a review of dental amalgam studies. More than 300 studies published between 1996 and 2003 were examined, with the LRSO finding little evidence to support a causal relationship" between amalgam fillings and health problems.

Unfortunately, there are individuals who promote the removal of amalgam fillings as a cure for multiple sclerosis or claim that amalgam fillings cause Parkinson's or Alzheimer's disease. These claims are occasionally sensationalised in the media. Nonetheless, no credible scientific study has ever found a connection found between amalgam fillings and any health disorder.

Can the mercury in amalgam leach into the body and cause health problems?

Amalgam fillings may release minute amounts of mercury vapour under the pressure of chewing or grinding, but there is no scientific evidence that such low-level exposure is harmful. The amount of vapour released varies between 1 and 3 micrograms per day. (One microgram is equal to 35.2 billionths of an ounce).

Is it possible to have an allergic reaction to amalgam?

Very few cases of an allergic reaction to amalgam have ever been reported. In rare instances, the mercury in amalgam may trigger an allergic response similar to a skin allergy. Usually patients who have a family history of metal allergies are more susceptible. If you have concerns, discuss them with your dentist.

What other options are available for dental fillings?

Composite resin fillings can also be used to repair teeth damaged by cavities. Composite fillings are tooth-coloured, so they blend in with teeth and look natural. Composites are often used on the front teeth where a natural appearance is important. They can be used on the back teeth as well, depending on the location and extent of the tooth decay. Composite fillings are made from glass and resins. They are usually more costly than amalgam fillings.

Resin and glass-ionomers are made from ground glass and acrylic acid. They both mimic the colour of teeth, although they are not translucent like natural tooth enamel. These fillings are usually only placed on surfaces that do not undergo much wear or pressure, as these fillings have low resistance to breaking and are best used only for small fillings.

Amalgam: Myths vs. Facts

The following information from the American Dental Association corrects much of the misinformation about silver-coloured fillings known as amalgam.

Myth: Dental amalgam causes numerous health problems.
Not true. You should feel very secure that the many organisations responsible for protecting the public's health have said time and time again that amalgam fillings are safe. Those organizations include the World Health Organization, United States Public Health Service, the National Institutes of Health and the Food and Drug Administration.

Myth: There are better materials for treating cavities, but the ADA continues to promote use of dental amalgam because it receives money from amalgam manufacturers through its Seal of Acceptance program.
Be assured that the ADA does not profit from amalgam, nor does it promote the material. The cost of maintaining the ADA Seal program is financed primarily through ADA member dentist dues.

What the ADA does promote is having patients make informed decisions about their dental care in consultation with their dentist. The choice of a particular filling material is determined in partnership by the dentist and patient, and based upon a variety of considerations, including size and location of the cavity, patient history, cosmetic concerns and cost.

Myth: The ADA justifies amalgam use by saying the filling has been around for 150 years.
When making treatment recommendations, dentists rely on the best-available science and their own clinical experience. Because amalgam has been around so long, the dental profession and scientific community have learned a great deal about its durability, reliability and safety. Just like aspirin, amalgam has withstood the test of time and is still a valued option for patients.

Myth: Removal of amalgam cures some diseases.
It is unconscionable to lead people to believe that their serious illnesses may improve by undergoing unnecessary dental treatment. In fact, leading medical experts and health organizations have negated such statements and conclusions. For example:

• "There is no scientific evidence to connect the development of MS or other neurological diseases with dental fillings containing mercury." (National Multiple Sclerosis Society)
• "According to the best available scientific evidence there is no relationship between silver dental fillings and Alzheimer's." (Alzheimer's Association)
• "There is no scientific evidence of any measurable clinical toxic effects [of dental amalgam]." (American Academy of Pediatrics)

Myth: Dental amalgam fillings release mercury vapours that are harmful to the body.
Minute amounts of mercury vapour (between 1-3 micrograms* per day) may be released from amalgam under the pressure of chewing or grinding, but there is no scientific evidence that such low-level exposure is harmful. In fact, dental materials experts say one would have to have almost 500 amalgam fillings to even see the subtlest symptoms in the most sensitive person.

* 1 microgram is equal to 35.2 billionths of an ounce.

Myth: Dentists cannot tell their patients that amalgam contains mercury.
Actually, the ADA encourages dentists to discuss the full range of filling options with their patients so together they can decide what is the most appropriate treatment.

Key resources for oral health care information and additional information about amalgam:

The American Dental Association
The Food and Drug Administration