A controversial area of immunotoxicology which has stirred considerable media attention and controversy since the mid 80’s concerns the evidence suggesting that common silver dental fillings are causing or worsening various health disorders and immune system problems.

What’s In Silver Fillings?

The silver fillings that the dentist puts into your mouth are actually made of 52% mercury and the rest copper, tin, silver and zinc. It is now a documented fact that silver/mercury fillings release mercury vapor into the mouth, especially when you chew or eat hot or acidic foods. In research conducted at the University of Calgary in Canada, chewing increased the mercury levels within the air in the mouth six-fold among test subjects. The greater the number of fillings, the more mercury vapor was released. The researchers next step was to find just where this mercury was going. In other investigations from the Department of Radiology at the University of Calgary, it was found that substantial quantities of mercury lodged in the lungs, gastrointestinal tract and jaw tissue. Other sites of substantial mercury placement were the brain, heart and several endocrine glands. The researchers stated, "From our results we conclude that dental amalgams can be a major source of chronic mercury exposure."

T-Cell Counts Improve After Filling Removal

Effects upon the immune system provide some of the strongest evidence that mercury fillings are causing harm. David Eggleston, an American Dentist, published a report of his work in the 1984 Journal of Prosthetic Dentistry. Dr. Eggleston measured the T-lymphocytes on three patients before and after removing the silver/mercury fillings In all cases, the percentage of T-lymphocytes went up substantially. One patient, after filling removal showed an increase of 55%. He then reinserted the silver/mercury filling in two of the patients as a reverse test. In both cases, the percentage of T-lymphocytes decreased again. Finally, he removed the new filling and replaced them with a non-mercury filling, the T-cells went up again, in one case an increase of 30%. Dr. Eggleston has done 30 such immune system tests before and after removal and showed an average improvement in T-cells of 30%.

Dr. Hal Huggins is another dentist who has researched the problems caused by mercury based fillings. Dr. Huggins, who also has a Masters Degree in Immunology, stated, "At the University of Colorado, I’ve measured T-cell rises of 100-300% after fillings were removed. These findings could mean that amalgams have some role in causing allergies and autoimmune diseases."

Fillings Linked To Chronic Tiredness

Dr. Huggins says that 90% of his 2000 patients have symptoms of fatigue which improves when the fillings are removed. He explains there is evidence to support why this is happening from a biological viewpoint - Mercury interferes with the oxygen carrying capacity of red blood cells. In most of his patients who are given the "oxyhemoglobin test," the oxygen carrying capacity of red blood cells is about half of what it should be. This explains the chronic tiredness in the presence of normal hemoglobin levels.

In a related research project discussed in the 1975 Critical Reviews in Toxicology - low levels of mercury were found to slow the uptake of glucose into the brain and glucose is the primary "fuel" your brain uses for energy.

Politics and Silver Fillings

Most people assume that if mercury fillings were really harmful that the American Dental Association would admit the problem and stop their use. Of course, this will never happen. Keep in mind that the majority of the U.S. population over the age of 15 has some silver/mercury fillings. If the American Dental Association was to ever officially state these fillings were potentially harmful, they would also be acknowledging guilt, and therefore acknowledging liability. They would put themselves and all dentists into the position of not only having to replace the fillings without charging the patients (since they made the error), but they would also set themselves up for an onslaught of legal action from people experiencing health problems related to the mercury based fillings. Therefore, what we will most likely see is a gradual transition away from the silver/mercury fillings by dentists providing other filling options such as porcelain, plastic/glass composites and gold, while at the same time telling their patients that silver/mercury fillings do not cause any problem. But at least now you know why they have to tell you mercury fillings are "safe."