FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

NO NEED TO REPLACE EFFECTIVE AND SAFE MERCURY-SILVER FILLINGS

Question: I recently heard a dentist on a radio talk show saying that silver amalgam dental fillings are dangerous and can cause Alzheimer's disease and some forms of cancer. He recommended having all of your silver fillings taken out and replaced with newer types of filling material. Is this good advice?

Answer: Despite much progress in preventive dentistry, people still get cavities. The proper way of dealing with dental decay involves removing the damaged area and repairing the subsequent defect with a material that is both hard and longwearing.

One persistent dilemma the dentist confronts is the difficulty of finding a suitable filling material that can be shaped to fit into and tightly seal the properly prepared cavity space. An amalgam provides a particularly good solution for this problem. An amalgam is a mixture of mercury, which I'm sure you know is a liquid at room temperature, and powered metal. The most common filling material is comprised of about 50 percent metallic mercury and about 50 percent finely powdered silver. There are usually trace amounts of tin and copper present as well. Within a few minutes of mixing these ingredients together, they form a soft moldable material that can be tightly fitted to fill the cavity. In a few more minutes, this amalgam becomes a solid metal that is the material we know as a "filling." Mercury-silver amalgam has been the most commonly used filling material for the last 160 years.

A variety of materials have been used for dental fillings over the last few centuries, however. Lead, tin, silver, gold and plastic are a few of the materials that have been used extensively at one time or another. Mercury certainly can be hazardous to our health. High levels of exposure can cause damage to the nervous system, kidneys and liver. Consequently, there has been a century-long debate about the safety of using mercury-silver amalgam fillings because a small amount of the amalgam is ingested as the fillings wear down. Despite many high-quality research studies, there has been no link established between these fillings and Alzheimer's, cancer or multiple sclerosis. In fact, the only known disorder linked to their use is a rare allergy to mercury that in some people can produce mouth irritation. And for the record, other filling materials, particularly the new plastic ones, have an even higher risk of causing this type of allergic reaction.

So why are there people out there preaching that we should all have our amalgam fillings removed? Well, I'd guess that this contrived controversy provides an opportunity for those preachers to grab a bit of fame and glory. Or perhaps, as the common saying suggests: "A fool and his money are soon parted." I'd suggest that you listen to the radio for pleasure and listen to your dentist for good advice about your dental care.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701. Past columns are available online at http://www.FamilyMedicineNews.org.