LONDON (Reuters) - Mercury is a known poison that can damage the nervous system, so why is it still being used to fill cavities in peoples’ teeth?
The European Union is grappling with this issue as it faces pressure to ban mercury-bearing “amalgams” that some patients’ organizations say are dangerous, and counterarguments from dentists and some governments, who say the material is safer and more durable than alternatives.
The EU has commissioned two working groups to report back by year’s end, one on mercury’s effects on the environment and the other on the link between amalgams and human health.
The debate gives rise to strong emotions, particularly from anyone who has suffered from mercury poisoning.
“I was off work for 18 months and had a telephone directory of symptoms,” said UK coordinator Michele Payne of the worldwide organization D.A.M.S. (Dental Amalgam Mercury Syndrome).
Mercury, which accounts for 50 percent of an amalgam filling, cannot be degraded and persists in soil, water and living organisms and while high doses can be fatal, relatively low doses have been linked to adverse neuro-development impacts.
Most countries advise against use of amalgam for children and pregnant women due to its negative effects on brain development, but patient organizations believe the rest of the population, carrying an average of 2.5 grams in their mouths, is also at risk.
The amount may seem small, but it works out to 1,225 tonnes of mercury in the mouths of the population of Europe.
“At least one percent of those who have dental amalgam could be affected by mercury,” university teacher Servando Perez Dominguez of the Spanish patients organization Mercuriados said.
One percent account for some 4.9 million Europeans.
“There are other alternatives that are safer ... we try to tell people and even politicians as in the end it will be a political decision,” Perez Dominguez said.
The list of effects from mercury poisoning goes from mild tremors due to neurological damage and kidney problems to autism and even Alzheimers, according to advocates for a European ban.
Others say studies pointing to these symptoms are flawed.
“There is no evidence that amalgam fillings cause anybody any sort of illness or unwellness, unless you are truly allergic to the materials in the amalgam fillings in which case removal of the fillings will cure the symptoms,” said Susie Sanderson, chairperson of the British Dental Association.
Together with the Brussels-based Council of European Dentists, the association opposes a phase out or ban of amalgam.
“It is important we have different materials for patients with different needs,” Mark Beamish, the council’s EU affairs officer, said, adding that some people were allergic to alternative materials such as composites and plastics.
The use of amalgam has declined in most European countries as more people opt for aesthetic white composite fillings and in many countries dental hygiene overall has improved, resulting in fewer cavities.
“But there are other countries like Poland, Hungary and the Baltic states, where caries are comparatively high with a factor of three or four or even higher,” Professor Gottfried Schmalz at the German University of Regensburg, said.
In many countries, such as the Netherlands, many patients opt for cheap amalgam fillings, costing around two thirds of alternative fillings. Similarly, where dentists work in a national health system, such as in the United Kingdom, critics say amalgam is put in by default to save government money.
“Restrictions on the use of amalgam would damage the financial stability of health systems as well as impact on individual patients’ ability to afford dental care,” a paper from the European Dental Association said in May 2007.
In 1999 the Swedish Parliament decided no financial support should be given for amalgam fillings via the national dental insurance system and by 2003, the share of amalgam was some 6 percent of all filling material at around 100 kilogram.
“In Sweden we have said amalgam should not be used because of environmental reasons,” dentist Nils Rene at Sweden’s National Board of Health and Welfare said.
Amalgam waste is the biggest source of mercury in EU waste water and dental use also leads to the widespread dispersal of mercury into the atmosphere from cremation.
In the UK dental amalgam and mercury from laboratory and medical devices, account for about 53 percent of total mercury emissions and annually 7.41 tonnes of mercury from amalgam are discharged to the sewer, atmosphere or land.