Dental Amalgam

Dental Amalgams

What is dental amalgam?
Most people recognize dental amalgams as silver fillings. Dental amalgam is a mixture of mercury, and an alloy of silver, tin and copper. Mercury makes up about 45-50 percent of the compound.

Mercury is used to bind the metals together and to provide a strong, hard durable filling. After years of research, mercury has been found to be the only element that will bind these metals together in such a way that can be easily manipulated into a tooth cavity

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Is mercury in dental amalgam safe?
Mercury in dental amalgam is not poisonous. When mercury is combined with other materials in dental amalgam, its chemical nature changes, so it is essentially harmless.

The amount released in the mouth under the pressure of chewing and grinding is extremely small (1-3 micrograms)** and no cause for alarm. In fact, it is less than what patients are exposed to in food, air, and water ( 5-7 micrograms a day)**.

Ongoing scientific studies conducted over the past 100 years continue to prove that amalgam is not harmful. Claims of diseases caused by mercury in amalgam are anecdotal, as are claims of miraculous cures achieved by removing amalgam. These claims have not been proven scientifically

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Why do dentists use dental amalgams?
Dental amalgam has withstood the test of time, which is why it is the material of choice. It has a 150-year proven track record and is still one of the:

safest

durable

least expensive materials to a fill a cavity.

It is estimated that more than 1 billion amalgam restorations (fillings) are placed annually. Dentists use dental amalgams because it is easier to work with than other alternatives. Some patients prefer dental amalgam to other alternatives because of its safety, cost-effectiveness, and ability to be placed in the tooth cavity quickly

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Why don't dentists use alternatives to amalgam?
Alternatives to amalgam:

cast gold restorations

porcelain

composite resins are more costly.

Gold and porcelain restorations take longer to make and can require two appointments. Composite resins, or white fillings, are esthetically appealing, but require a longer time to place the restoration. It should also be known that these materials, with the exception of gold, are not as durable as amalgam

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What about patients allergic to mercury?
The incidence of allergy to mercury is far less than one percent of the population. People suspected of having an allergy to mercury should receive tests by qualified physicians, and, when necessary, seek appropriate alternatives. Should patients have amalgam removed?

No. To do so, without need, would result in unnecessary expense

potential injury to teeth

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Are staff occupationally exposed?
Dentists are using pre-mixed capsules, which reduce the chance of mercury spills. And newer, more advanced dental amalgams are containing smaller amounts of mercury than before.

An interesting factor can be brought into this: Because dental staff are exposed to mercury more often, one would expect dental personnel to have higher rates of neurological diseases, such as multiple sclerosis. They do not.

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What are other sources of mercury?
Mercury can be found in:

air

food

water.

We are exposed to higher levels of mercury from these sources than from a mouthful of amalgam.

Updates:

ADA Testifies Before FDA on Dental Filling Safety Story Receives Widespread Media Coverage

The U.S. Food and Drug Administration is holding a two-day panel meeting today and tomorrow to gather facts and opinions regarding dental amalgam. ADA representatives, as well as a number of witnesses from other dental organizations, are testifying at the meeting. Numerous other individuals will also testify, including two international participants describing the basis for their countries' regulation of amalgam. Time has been set aside for comments from the public, and we expect a number of dental amalgam opponents will share their views.

The FDA has prepared a draft report in advance of the meeting that supports the safety of dental amalgam. No specific FDA regulatory action is expected; however, this meeting has received widespread media coverage due primarily to Associated Press and CBS network radio stories. Both stories cited the ADA's position that the weight of scientific evidence indicates dental amalgam is a safe and effective restorative material. NBC Nightly News is also covering this story, and may air its segment tomorrow night.

* Dentists welcome this review of the science by the FDA.
* The overwhelming weight of scientific evidence, including two recent clinical trials published in the Journal of the American Medical Association, support the safety and effectiveness of dental amalgam.
* Dental amalgam contains elemental mercury combined with other metals such as silver, copper, tin and zinc, which forms a safe, stable cavity-filling material. It's important to note that dental amalgam has entirely different properties than mercury by itself.
* Amalgam is one of several safe, effective materials to fill cavities. Other materials include gold and tooth-colored fillings.

More information:
* A news release about the FDA meeting and testimony from our three representatives is posted on ADA.org <http://www.ada.org/public/media/releases/0609_release01.asp> .
* Dental Filling Options: information for patients <http://www.ada.org/public/topics/fillings.asp>
* An ADA press statement <http://www.ada.org/public/media/releases/0604_release03.asp> on the dental amalgam clinical trials published in the Journal of the American Medical Association.
* A Journal of the American Dental Association patient page entitled, <http://www.ada.org/prof/resources/pubs/jada/patient/patient_52.pdf> When A Filling Needs to be Replaced

9/06

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Are amalgam dental restorations containing mercury safe for children? Children who received dental restorative treatment with amalgam did not score significantly better or worse on neurobehavioral and neuropsychological assessments than children who received resin composite material. Children who receive restoration with resin may be more likely to need additional treatment. Studies evaluating outcomes for longer than 5 to 7 years are needed. (LOE = 1b) Reference Bellinger DC, Trachtenberg F, Barregard L, et al. Neuropsychological and renal effects of dental amalgam in children. A randomized clinical trial. JAMA 2006;295:1775-1783.

Mercury Fillings in Moms Don't Lead to Small Babies
Risk of low birth weight infants debunked in new study

In good news for expectant moms with cavities, a new study suggests pregnant women aren't threatening their newborn's birth weight by getting mercury-based silver amalgam fillings.

This latest research revealed no connection between use of the fillings and low birth weight.You cannot prove absolute safety, but mercury seems to have quite a bit of data on it now indicating that it shouldn't be of concern.

The use of silver amalgam fillings has dipped over the past couple of decades. They made up 68 percent of all fillings in the United States in 1990, but dropped to 30 percent in 2003.Resin-based fillings known as "white" fillings have become more popular, and some dentists have abandoned silver fillings because of concerns about the safety of mercury.

While silver amalgam fillings are commonly known just as "silver," they're actually made of several metals, including silver, tin, mercury and copper. The fillings "are a very good filling material. They're very long-lasting and have good properties as far as dental material.

Concerns about mercury exposure have grown in recent years, especially regarding its presence in foods such as fish. However, the U.S. government has declared that there is "scant evidence that the health of the vast majority of people with amalgam (fillings) is compromised."

In the new study, Hujoel and his colleagues studied a dental insurance company's records of 1,117 Washington state women who gave birth to low-weight infants and 4,468 women who gave birth to infants of normal weight.

The findings appear in the April 15 issue of the American Journal of Epidemiology.

The researchers found no connection between getting amalgam fillings during pregnancy -- nearly 5 percent of the women did so -- and giving birth to a underweight baby. Even women who had as many as 11 fillings during pregnancy weren't more likely to give birth to a low-weight child.

The study is another paper in a growing body of evidence that amalgam is safe and effective way to repair teeth that have been damaged by decay or trauma.

Learn more about amalgam fillings from the U.S. Centers for Disease Control and Prevention.

By Randy Dotinga HealthDay Reporter

SOURCES: Philippe P. Hujoel, Ph.D., D.D.S., professor, dental public health sciences, University of Washington, Seattle; Dr. Rod Mackert, D.M.D., Ph.D., spokesman, American Dental Association, and professor, dentistry, Medical College of Georgia, Augusta; April 15, 2005, American Journal of Epidemiology

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New Study Backs Amalgam

A new study, conducted by leading scientists from highly regarded research and academic institutions, finds no link between amalgam exposure and neurological function, reports the American Dental Association.

`Our findings do not support the hypothesis that exposure to amalgam produces adverse, clinically evident neurological effects,' concludes Albert Kingman, Ph.D., Chief, Biostatistics Core, at the National Institute of Dental and Craniofacial Research. The team tested for abnormal tremors, coordination, station or gait, strength, sensation and muscle stretch reflexes.

The study followed 1,663 subjects of the ongoing Air Force Health Study of Vietnam era veterans. An oral health examination has been part of the standard AFHS medical examination since 1992 because `peripheral neuropathy' is considered to be an important adverse neurological effect of high levels of exposure to elemental
mercury. This refers to an abnormality in sensation, such as vibration sensation at the ankle, pinprick sensation at the great toe and/or absence of ankle reflexes.

The study found no connection of amalgam to any level of peripheral neuropathy. We were unable to detect any associations between amalgam exposure and clinical signs of either neuropathy or a diminished sensation of the big toe among adult males - these are standard measures for diagnosing clinical neuropathy.

The research appears in the March 05 issue of NeuroToxicology.

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Study backs amalgam
Top scientists find no link to neurological functions

A new study, conducted by leading scientists from highly regarded research and academic institutions, finds no link between amalgam exposure and neurological function. Our findings do not support the hypothesis that exposure to amalgam produces adverse, clinically evident neurological effects.

These effects tested, as part of the overall neurological evaluation, include abnormal tremors, coordination, station or gait, strength, sensation and muscle stretch reflexes.

An oral health examination has been part of the standard AFHS medical examination since 1992 because "peripheral neuropathy" is considered to be an important adverse neurological effect of high levels of exposure to elemental mercury. "Peripheral neuropathy" refers to an abnormality in sensation, such as vibration sensation at the ankle, pinprick sensation at the great toe and/or absence of ankle reflexes.

But as with other neurological effects, the study found no connection of amalgam to any level of peripheral neuropathy. They were unable to detect any associations between amalgam exposure and clinical signs of either neuropathy or a diminished sensation of the big toe among adult males — these are standard measures for diagnosing clinical neuropathy.

This study represents another important piece to the research puzzle because of the unique military population tested. The results should be taken in the context of the larger group of clinical studies that have not found direct evidence linking amalgam exposure to impaired neurological function or peripheral neuropathy.

The bottom line is there was no association between abnormal neurological signs and amalgam exposure. So these findings do not support the hypothesis that amalgam exposure produces clinically evident neurological effects."

The NIDCR-led research was conducted because "concerns regarding the safety of silver-mercury amalgam fillings continue to be raised in the absence of any direct evidence of harm," the study reads. "The widespread population exposure to amalgam mandated that a thorough investigation be conducted of its potential effects on the nervous system."

Amalgam is a safe dental restorative material. This study, like the recently published report by the independent, nonprofit Life Science Research Office, which extensively reviewed the literature and concluded that amalgam is safe to use in people, adds to the definitive scientific evidence attesting to amalgam's demonstrated track record of safety.

The LSRO report's executive summary can be downloaded at no cost by visiting "www.lsro.org", click on "Review of Dental Amalgams." To obtain the full text, call the LSRO bookstore at 1-301-634-7030. By Mark Berthold Rsearch by by Albert Kingman, Ph.D., Chief, Biostatistics Core, at the National Institute of Dental and Craniofacial Research, part of the federal National Institutes of Health. "Amalgam Exposure and Neurological Function," appears in the March issue of NeuroToxicology. It followed 1,663 subjects of the ongoing Air Force Health Study of Vietnam era veterans.

Sources:
Much of this information was received from Jack Mitchem, DMD, professor of dental materials at Oregon Health Sciences University Dental School and past chairman of the American Dental Association Council on Dental Materials, Instruments and Equipment.
AGD Impact thanks Recall, the Oregon AGD newsletter, which also contributed to portions of this fact sheet.

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