Sinking our teeth into the debate
Ali Farahani, DDS
The debate continues over the possible negative health effects of mercury dental fillings. It has raged on for years and shows no sign of reaching an end.
The debate continues over the possible negative health effects of mercury dental fillings. It has raged on and on for years and currently shows no sign of reaching any definitive end. But what is fact and what is fiction?
Fiction 1: My fillings are made of silver, not mercury.
The facts: Silver comprises only about 35 percent of the restorative material (amalgam) used to fill your teeth. Fifty percent of silver-coloured dental amalgam is elemental mercury.
Fiction 2: We get more mercury from eating fish than we do from our dental fillings
The facts: Mercury from dental fillings is the primary source of mercury exposure for humans. Mercury is released from dental amalgam, exposing the individual to elemental mercury vapour. According to the World Health Organization, eating fish exposes us to 2.34 mcg daily, whereas chewing on mercury fillings exposes us to between 3 and 17 mcg every day, depending on the number of fillings in the mouth.
Fiction 3: Mercury is locked into tooth fillings and cannot leach into the body.
The facts: Mercury is released from fillings. Researchers observed that after chewing, people with mercury fillings had almost 20 times more mercury vapour in their mouths than those without mercury fillings.
Fiction 4: Any mercury vapour that is released from tooth fillings may enter the body, but it just passes through.
The facts: Mercury vapour does indeed pass from the fillings and into our organs. Furthermore, it passes from a pregnant mother into her fetus. Researchers at the University of Calgary “tagged” mercury with radioactive Hg isotopes so that it could be tracked and unmistakably traced back to tooth fillings. Researchers placed these tagged mercury fillings into pregnant sheep and investigated where in the body the mercury travelled. Their results were telling. All tissues examined in both mother and fetus (brain, heart, kidney, liver, muscle, stomach, and colon) collected tagged mercury.
Fiction 5: Drilling out mercury fillings will rid the body of mercury.
The facts: Taking a drill to the mercury fillings and replacing them with white fillings will not eliminate mercury in the body. Swedish researchers found that drilling out fillings had a statistically significant impact on the mercury levels found in blood and urine.
Fiction 6: There is no way to remove the mercury fillings and reduce the body burden of mercury.
The facts: One way to remove mercury fillings with less of an increase in mercury exposure is to visit a dentist who is accredited with the International Academy of Oral Medicine and Toxicology (IAOMT). The IAOMT educates dentists and allied professionals in methods of dealing with mercury fillings. More than 500 IAOMT accredited dentists are registered on the IAOMT website (iaomt.org).
Is Mercury Doing Harm in the Body?
Research published in 2004 in the journal Toxicological Sciences investigated whether mice that were given low levels of mercury vapour similar to what humans receive from mercury fillings would experience neuro-behavioural effects after six months. Researchers found that mice that did not have the protective metal-binding protein (metallothionein) exhibited significantly higher incidence of anxietal behaviours and poorer learning and memory function.
Fortunately, humans have access to large quantities of protective metallothionein, provided that we consume adequate levels of the dietary minerals zinc, copper, and selenium and the amino acids histidine and cysteine.
Thoughts to Chew Over
The average 50-year-old likely had their first mercury filling at about age six and has had many fillings since then. That’s more than 44 years of mercury exposure. We have yet to determine the behaviour and learning changes after 10, 20, 30, or more years of exposure to mercury amalgam. More research needs to be done.
I firmly believe it is the responsibility of health care professionals to stay the scientific course and not take extreme positions either for or against mercury. This element is not an evil villain intent on spreading toxicity to the masses. It has uses in mining, the battery industry, and in refining gold. But, should it be in our teeth?
That decision is up to you.