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Friday, June 6, 2008

Are Silver-Mercury Amalgams Dangerous? FDA May Be Changing Its Position.

Silver-Mercury amalgams (also know as silver fillings) have been controversial ever since their invention about 150 years ago. Amalgam is created by combining a silver alloy (metal) powder with liquid mercury at about a 50/50 ratio. In a few minutes the mixture hardens to a solid mass. While many recognized health organizations have never been able to find a connection between these fillings and any illness or disease, the material has always precipitated heated debate.

Amalgam occupies a prominent place in the history of dentistry. It is a material that is relatively easy to use. It lasts a long time in the mouth. And, it's relatively inexpensive. No doubt, it has kept billions of teeth from being lost to decay / cavities. It simply WORKS.

Over the course of dental history, there have been (and are) alternative materials, each with its own advantages and disadvantages: gold, composite (a tooth-colored plastic), and porcelain, as examples.

Today, the most commonly used alternative to amalgam for fillings is composite. Composite is a high-tech plastic that mimics the color of teeth. It is a far more demanding material in terms of the doctor's technique. Done meticulously, though, it performs very well. And, cosmetically, it looks far better. It's disadvantages include: technically challenging to perform, more expensive, and may not last as long. If composite is not placed with technical perfection, it tends to fail catastrophically.

I have not placed a silver / mercury amalgam in over 12 years. I discontinued amalgam in my office for a number of reasons. However, I've never felt it was a significant health hazard. I simply believe composites are a better service.

The primary reason I switched to composite was conservation of natural tooth structure. Since composite bonds to teeth, we don't have to cut away healthy tooth structure to create mechanical locks, as we do with silver amalgam that does not bond to teeth. Amalgam has to be mechanically locked into the tooth. This is done by making the "hole" bigger at the bottom than at the top. So, when the amalgam hardens, it locks in. This requires possibly removing healthy tooth structure to create this mechanical "retention." Composite requires me to only remove decayed structure - or just the cavity. After that, the composite bonds to the remaining healthy tooth firmly without having to create "mechanical retention."

All that said, it's interesting that in many parts of the U.S. it's illegal to dump silver / mercury amalgam waste into the garbage or down the drain. In many places it has to be collected and disposed of as hazardous waste. Dentists have to pay a special service to haul it away for recycling or refining. So, the same government that has been telling us that amalgam is safe for use in our MOUTHS, also is telling us that it's an environmental hazard. It's OK to put it in your mouth, but don't put it in the garbage! Figure out THAT logic!

So, where do we stand? The FDA is reclassifying amalgam. What does that mean? I'm not sure. Click on the link above and see what you think. Not surprisingly, the our illustrious government is rather vague. It may mean that dentists who use it may have to warn their patients about possible hazards. I'm guessing not many will choose it! I suspect this is the first step in banning amalgam.

Do I really believe it's a health hazard? Probably not for most people. No doubt, we get more mercury from our environment than we ever will from dental fillings. The vast majority of electric power comes from coal burning plants in the U.S. And, those plants dump TONS of mercury into our environment every year. Fillings are really insignificant sources of mercury, if any at all.

Do I recommend you have all your silver fillings replaced? No. If an old filling is broken down or has new decay, then yes... go ahead and replace it. However, I have no objection to replacing unsightly silver amalgam fillings with composite or porcelain for cosmetic reasons, as well. But, as it stands now, there is no reason to have all your fillings removed for health reasons. And, you should know that every time we work on a tooth, there are risks, which may include the need for root canal treatment. Larger amalgams may require restoration with a crown.

Stay tuned!