The controversy surrounding the use of mercury in amalgam fillings seems set to run and run, reports SYLVIA THOMPSON
THE USE of mercury amalgams in tooth fillings is sometimes described as one of the oldest unresolved controversies in medicine. There are opposing sides each equally convinced of their arguments which often leave people with a lingering uncertainty about the safety of having a toxic metal in their mouths for decades on end.
Last week’s ITV Tonight documentary highlighted the issues again, reminding us that the largest source of mercury exposure for most people in developed countries is inhalation of mercury vapour from dental amalgams.
English author Terry Pratchett controversially blamed amalgam fillings for his Alzheimer’s disease. “Having something like mercury in your mouth seemed to me to be a really bad idea and I got rid of the stuff,” says Pratchett, noting that his dentist disposed of his old fillings into a special unit for toxic waste.
The problem is that despite significant numbers of often highly emotional personal testimonies about illnesses caused by mercury poisoning from dental amalgams, the evidence is scant.
Some studies have shown higher mercury concentrations in brains of deceased and in the blood of living patients with Alzheimer’s disease. Others have shown an association between amalgams and multiple sclerosis but no association between amalgams and chronic fatigue syndrome.
In Ireland, there are a small number of so-called holistic dentists who will remove amalgam fillings and replace them with composite fillings. Typically, this procedure will cost €150-€200 per filling and is usually followed by a detoxification regime for up to six months afterwards.
None of these dentists would go on the record for this article yet pointed to a postal survey which found that 72 per cent of patients who had amalgams removed and detoxification reported that their symptoms were much improved or had gone.
Getting a diagnosis of mercury toxicity remains one of the greatest difficulties as many of the symptoms associated with it, can be caused by other conditions.
Dr Joe Fitzgibbon, an allergy specialist, says he has seen patients who have had their dental amalgams removed and replaced with composites. “These are often patients who are desperate to find a reason for their fatigue but I’ve yet to see a single patient improve with this procedure,” he says.
Dental associations around the world acknowledge that there is a very small number of people who are allergic to mercury but, apart from this, the risks of mercury leaching into your body from amalgams is small. Yet, in Britain in 1998, a Department of Health committee advised women to avoid “where clinically reasonable, the placement or removal of amalgam fillings during pregnancy”.
Pregnant women are similarly advised to avoid eating too much fish (particularly large fish such as shark and tuna) due to possible residues of mercury.
Tom Feeney, a Dublin-based dentist who is a board member of the Council of European Dentists, points to the EU’s Scientific Committee on Emerging and Newly Identified Health Risks which states that “the current use of dental amalgams does not pose a risk to health apart from allergic reactions”.
He adds that modern methods of using mercury in sealed capsules which are then mixed in a machine reduce risks of mercury vapour in dental surgeries. He says that amalgam fillings remain the most durable and affordable material to work with for dentists. “If I had a material as good as it to use instead, I would,” says Feeney. However, he acknowledges that amalgam use is reducing. “Yes, there is a movement towards white fillings which is mainly happening for cosmetic reasons.”