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Do Metal Amalgam Fillings Contain Mercury?
Yes. In fact, they more than contain it, they are 50% mercury by weight. The rest of the filling is made up of a powder of silver, copper, and tin (itself a toxic metal).
Mercury is a liquid metal, and the process of making metal amalgam fillings is like making a mud pie. The liquid mercury is mixed with the powder until it creates a shapeable paste, which is then jammed into your tooth.
The problem is that mercury, like water, evaporates, so metal fillings give off mercury vapor that you inhale on a daily basis. Mercury also migrates through your teeth and into your bloodstream.
Are Silver Mercury Fillings Harmful?
The short answer is we don’t know. The FDA and others are convinced that mercury exposure from metal amalgam fillings is not harmful. You can read the 2009 FDA statement on metal amalgam fillings to see what they recommend. The statement is largely based on a 2004 survey of research that says there is “little evidence” of the dangers posed by mercury from amalgam fillings.
However, we do know that mercury is toxic, and we know that mercury doesn’t stay in your fillings. In the 1980s, researchers gave a pregnant sheep metal amalgam fillings marked with radioactive mercury (which doesn’t occur in nature). They killed the sheep 30 days later, removed the filling and looked at the presence of radioactive mercury in the sheep’s body. They found that in 30 days the mercury had migrated to the jawbone, and was also found in significant concentrations in the liver, kidneys, and digestive tract. In fact, all the tissues in the body were exposed to mercury, including the developing fetus. An experiment with a monkey gave the same results.
The amount of mercury exposure a person receives from dental fillings depends on the number of surfaces of metal amalgam they have. Two different studies in the 1990s estimated the number of fillings necessary to create a harmful exposure. One study estimated that a person would need to have 450 fillings to receive a toxic exposure. Another study concluded that adults might receive toxic exposure from as few as 2 metal amalgam fillings. More recent analysis suggests that the number of surfaces that can lead to toxic exposure is 6 for children, 8 for adults and older teens.
Again, the FDA has concluded that metal amalgam fillings are safe. Other regulatory agencies are not so sure. Germany, Austria, and Canada have said metal amalgam fillings should not be used on children and high-risk populations. Sweden and Denmark have banned all mercury-containing substances, including dental amalgam.
The Environmental Effects of Mercury in Dental Amalgam
We may not know whether dental amalgam is harmful to people, but we do know it is harmful to the environment, and may result in as much or more harmful exposure indirectly as it does directly.
The use of metal amalgam fillings in dentistry created 40 to 50 tons of mercury a year during the early 2000s. How dangerous is this amount of mercury? An annual deposition of only 12.5 micrograms per year can contaminate a square meter of fresh water lake and make the fish in the lake too toxic to eat. Forty tons of mercury is equal to 36,287,389—36 million grams!—enough mercury to contaminate almost three trillion square meters of fresh water, or more than 700 million acres, the equivalent of 25 times the surface area of Lake Michigan and Lake Huron combined.
Clearly, the potential environmental impact of dental amalgam fillings is huge, and is a major reason why they are being banned in other countries. It is also why we should move away from using them.
Mercury-Free Fillings at our Philadelphia Dental Office
At Dental Excellence of Blue Bell, Dr. Kenneth Siegel uses only tooth-colored fillings, including both ceramic fillings and composite plastic ones. These are not only safer for our patients and the environment, they are more attractive and more functional.
If you are concerned about mercury fillings and want to either remove mercury fillings or get new fillings at a mercurcy-free practice in Philadelphia, please call us at (610) 272-0828 or contact Dental Excellence of Blue Bell today for an appointment.