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Frequently Asked Questions Regarding Mercury Fillings


Are dental amalgams (mercury fillings) safe?


Yes. Dental amalgam has been used in tooth restorations worldwide for more than 100 years. Studies have failed to find any link between amalgam restorations and any medical disorder. Amalgam continues to be a safe restorative material for dental patients.


Is it possible to have an allergic reaction to amalgam?


Only a very small number of people are allergic to amalgam fillings. Fewer than 100 cases have ever been reported. In these rare instances, mercury may trigger an allergic response. Symptoms of amalgam allergy are very similar to a typical skin allergy. Often patients who are truly allergic to amalgam have a medical or family history of allergies to metals. If there is a confirmed allergy, another restorative material will be used.


Is it true that dental amalgams have been banned in other countries?


No. Erroneous news reporting has confused restrictions in a few countries with outright bans. Dentists around the world are using dental amalgams (silver fillings) to restore teeth that have dental decay. Studies have not shown a link between dental amalgam and any medical disorder.

Is there a filling material that matches tooth color?


Yes. Composite resins are tooth-colored, plastic materials (made of glass and resin) that are used both as fillings and to repair defects in the teeth. Because they are tooth-colored, it is difficult to distinguish them from natural teeth. 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 resins are usually more costly than amalgam fillings.


If my tooth doesn’t hurt and my filling is still in place, why would the filling need to be replaced?


Constant pressure from chewing, grinding or clenching can cause dental fillings, or restorations, to wear away, chip or crack. Although you may not be able to tell that your filling is wearing down, your dentist can identify weaknesses in your restorations during a regular check-up.


If the seal between the tooth enamel and the restoration breaks down, food particles and decay-causing bacteria can work their way under the restoration. You then run the risk of developing additional decay in that tooth. Decay that is left untreated can progress to infect the dental pulp and may cause an abscess.

If the restoration is large or the recurrent decay is extensive, there may not be enough tooth structure remaining to support a replacement filling. In these cases, your dentist may need to replace the filling with a crown.


American Dental Association Statement on Dental Amalgam
Revised January 8, 2002

Dental amalgam (silver filling) is considered a safe, affordable and durable material that has been used to restore the teeth of more than 100 million Americans. It contains a mixture of metals such as silver, copper and tin, in addition to mercury, which chemically binds these components into a hard, stable and safe substance. Dental amalgam has been studied and reviewed extensively, and has established a record of safety and effectiveness.

Issued in late 1997, the FDI World Dental Federation and the World Health Organization consensus statement on dental amalgam stated, "No controlled studies have been published demonstrating systemic adverse effects from amalgam restorations." The document also states that, aside from rare instances of local side effects of allergic reactions, "the small amount of mercury released from amalgam restorations, especially during placement and removal, has not been shown to cause any … adverse health effects."

The ADA’s Council on Scientific Affairs’ 1998 report on its review of the recent scientific literature on amalgam states: "The Council concludes that, based on available scientific information, amalgam continues to be a safe and effective restorative material." The Council’s report also states, "There currently appears to be no justification for discontinuing the use of dental amalgam."

In an article published in the February 1999 issue of the Journal of the American Dental Association, researchers report finding "no significant association of Alzheimer’s Disease with the number, surface area or history of having dental amalgam restorations" and "no statistically significant differences in brain mercury levels between subjects with Alzheimer’s Disease and control subjects."

The U.S. Public
Health Service issued a report in 1993 stating there is no health reason not to use amalgam, except in the extremely rare case of the patient who is allergic to a component of amalgam. This supports the findings of the Food and Drug Administration (FDA), the National Institutes of Health Technology Assessment Conference and the National Institute of Dental and Craniofacial Research, that dental amalgam is a safe and effective restorative material. In addition, in 1991, Consumer Reports noted, "Given their solid track record . . . amalgam fillings are still your best bet."

In 1991, the FDA’s Dental Products Panel found no valid data to demonstrate clinical harm to patients from amalgams or that having them removed would prevent adverse health effects or reverse the course of existing diseases.
The FDA's most recent reaffirmation of amalgam's safety was published on December 31, 2002.

The reaffirmation reads, “FDA and other organizations of the U.S. Public Health Service (USPHS) continue to investigate the safety of amalgams used in dental restorations (fillings). However, no valid scientific evidence has ever shown that amalgams cause harm to patients.”

It continues, “Also, USPHS scientists analyzed about 175 peer-reviewed studies submitted in support of three citizen petitions received by FDA after the 1993 report. They concluded that data in these studies did not support claims that individuals with dental amalgam restorations will experience problems, including neurologic, renal or developmental effects, except for rare allergic or hypersensitivity reactions.”

The U.S. Public Health Service found in 1993 "no persuasive reason to believe that avoiding amalgams or having them removed will have a beneficial effect on health." In fact, it is inadvisable to have amalgams removed unnecessarily because it can cause structural damage to healthy teeth.

The ADA supports ongoing research in the development of new materials that it hopes will someday prove to be as safe and effective as dental amalgam. However, the ADA continues to believe that amalgam is a valuable, viable and safe choice for dental patients and concurs with the findings of the U.S. Public Health Service that amalgam has "continuing value in maintaining oral health."


Dental Amalgam: Myths vs. Facts

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


Myth: Dental amalgam causes numerous health problems.


Fact: Not true. You should feel very secure that the many organizations 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.


Fact: 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.


Fact: 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.


Fact: 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 vapors that are harmful to the body.

Minute amounts of mercury vapor (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.


Fact: 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.


All this information was obtained from the American Dental Association Website: 14 September 2003 www.ada.org