Dental Amalgam

What is dental amalgam?
Most people recognize dental amalgam as silver fillings. Dental amalgam is a mixture of mercury, and an alloy of silver, tin and copper. Mercury makes up about 40-50 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.


Is mercury in dental amalgam safe?
Yes. Mercury in dental amalgam is not poisonous. Its release is extremely small. In fact, the amount released in a dental amalgam is much less than what patients are exposed to in food, air, and water. When mercury is combined with the other materials in dental amalgam, its chemical nature changes, so it is essentially harmless. 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.


Why do dentists use dental amalgam?
Dental amalgam has withstood the test of time, which is why it is the material of choice. Amalgam is a very durable material and has been used safely for more than 150 years. It is estimated that well over 1 billion amalgam restorations (fillings) are placed annually. Dentists appreciate using dental amalgam because it is easier to work with than other alternatives. Dentists also believe that patients prefer dental amalgam to other alternatives because of its safety, cost-effectiveness, and ability to be placed in the tooth cavity quickly.


Why don't dentists use alternatives to amalgam?
Alternatives to amalgam, such as cast gold restorations, porcelain, and composite resins are more costly. Gold restorations take longer to make, and porcelain and composite resins are esthetically appealing, but aren't as durable as amalgam in posterior (back) teeth.


What about patients allergic to mercury?
Patients are better served if we know what they're allergic to. The trouble is, a lot of people don't know what they are allergic to. 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, and potential injury to teeth.


Are staff occupationally exposed?
Dental staff are more occupationally exposed than patients. Necessary precautions should be taken, such as having open air ventilation, and being careful not to spill mercury. Dental personnel have been shown to excrete three to four times more mercury in their urine than the average patient. Studies have shown that dentists have not suffered from more mercury-related disorders than the general population. In the few instances when dentists have shown evidence of mercury disorders, these cases have been associated with poor mercury management in the dental office, especially mercury spills that have not been cleaned up properly. More dentists also 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.


What are other sources of mercury?
Mercury can be found in air, food, and water. We are exposed to higher levels of mercury from these sources than from a mouthful of amalgam.


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.

This information was compiled for you by the Academy of General Dentistry. Your AGD-member cares about long-term dental health for you and your family. The Academy's 36,000 general dentist members in the United States and Canada participate in an ongoing program of professional development and continuing education that keeps them upto date in dentistrv.

 

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Send comments to:Dr. Jay Last Update February 16, 2006