| Sunday, September 24, 2006
| METAL MOUTH:WHAT YOU SHOULD KNOW ABOUT THE MERCURY IN DENTAL FILLINGS
|WHETHER YOU HAVE A MOUTHFUL OF SILVER TEETH or just a few cavities, new questions about the safety of mercury fillings have made many of us nervous about our dental work.
Last week, an expert panel for the Food and Drug Administration rejected an agency report that had concluded mercury dental fillings are safe. In a 13-7 vote, panel members complained that the report excluded some important studies, making it impossble to reach a definitive conclusion about the safety of the fillings. The panel vote doesn't mean the fillings are'nt safe; it just means the experts felt that far more study is needed. Here are answers to some common questions about mercury fillings and your dental options.
Why are dentists using mercury in teeth?
Dentla amalgam has been in use for more than 100 years. It contains about 50percent mercury as well as a combination of metals, including silver, copper, tin and zinc. The amalgam starts as a putty-like substance that is mashed into the drilled-out tooh. It takes the shape of the cavity and the mercury triggers a reaction that cause it to harden. It's easy to use, cheap and durable. If you have a silver filling, chances are its' made of amalgam.
How much mercury are we exposed to from dental fillings?
Most Americans have sever or eight fillings. The amount of mercury relaaed daily is about one microgram per seven fillings, according to a 1997 World Health Organization report. A microgram is one millionth of a gram. By comparison, we absorb five to six micrograms of mercury from food and water sources each day, according to the Environm,ental Protection Agency. And the upper limit of permissible exposure set by governmentsafety standards for workers is equal to about 460 micrograms per day.
What do we know about the health risks of daily low-level mercury exposure from fillings?
We know dental amalgam release trace amounts of mercury vapor, but we don't know whether that has abt meaningful impact on a person's health. The World Health Organization has looked at various levels of mercury exposure and determined the threshold for when mercury exposure becomes toxic. Based on fillings to reach toxic levels of mercury exposure, according to J. Rodway Mackert, detal professor and materials science expert at the Medical College of Georgia in Augusta.
Even though the FDA panel was skeptical about the agency's report, panel members boted that dental amalgam likely is safe for most people. The question is whether certain groups, such as children and pregnant women, should avoid mercury-based fillings. "I have concerns not about what we know, but more about what we lack in knowledge", says panel consultant Michael Aschner, professor of pediatrics and pharmacology and a mercury expert at Vanderbilt University medical school in Nashville, Tenn.
Some consumers and advocacy groups believe there is a link between mercury fillings and multiple sclerosis. Alzheimers' disease and chronic-fatigue problems. There is no scientific cridible evidence supporting any link. But since the health impact isn't fully understood, serveral European conuntries have restricted use of deantl amalgam and ruled it should'nt be used in pregnant women.
Are there altenatives to mercury fillings?
Yes. About 15 years ago, two thirds of all dental fillings were made from amalgam, but today that number has dropped to about 30percent.Now dentists use resin composites --while fillings that match tooth color and are made of powdered glass and epoxy like materials. A blue light is used to make them harden. But studies show they often aren't as durable as amalgam. As a result, while fillings work well for small cavities and teeth that show in a smile, but many dentists still prefer to use amalgam. In back teeth and for large fillings.
Gold fillings and a combination of porcelain inlays are composite materials are also options, but they are time-consuming and expensive. Composite fillings can cost 30percent more than amalgam fillings and are far more likelty to wear out and need replacement. Patients can always ask their dentists what kind of material they plan to use on a tooth and request that dental amalgam not be used if they are concerned about mercury exposure.
Should we all have our silver fillings removed?
Unless your are having a problem with a tooth or a rare allergic reactions to your mercury fillings, most experts say it's not necessry to remove the fillings. Not only would the procedure be costly and typically not covered by dental insurance, but questions remain about whether you might be exposed to more mercury when the fillings is chipped away. Dr. Mackert notes that some studies have shown a temporary spike in urine levels of mercury when fillings are removed, but the increase lasts for only a few days.
Although Dr. Aschmer still has questions about the safety of mercury fillings, he has'nt opted to have a half dozen amalgams removed from his own mouth."But if one of my kinds needed a cavity filled, I would ask what are are my options," Dr. Aschner syas, "If composite resins are an option, I would defintely consider them over putting mercury in their mouths."
FILLING THE GAP
Here's a look at the pros and cons of various dental-filling options:
@ Amalgam: Durable amd cheap, contains mercury.
@ Composites: White color; costly and less durable.
@ Ceramic: Attractive, expensive and time-consuming.
@ Gold: Durable; expensive and requires two visits.
(Source:WSJ/HEALTH TODAY by: Tara Parker-Pope email@example.com)
|posted by infraternam meam @ 1:44 AM