Older dental fillings ‘unlikely to be toxic’

Scientists are suggesting mercury amalgam dental fillings may be less toxic than previously thought.

That’s the verdict of a new study appearing online in ACS Publication’s journal Chemical Research in Toxicology.

The scientists analysed the surface of freshly prepared metal fillings and compared these with the surface of aged fillings (about 20 years old) from a dental clinic.

Fresh fillings contained metallic mercury, which can be toxic.

However, aged fillings typically contain a form of mercury, called beta-mercuric sulfide or metacinnabar, which is unlikely to be toxic in the body.

The scientists found that the surfaces of metal fillings seem to lose up to 95% of their mercury over time.

Loss of potentially toxic mercury from amalgam may be due to evaporation, exposure to some kinds of dental hygiene products, exposure to certain foods, or other factors.

In 2008, Denmark joined Norway and Sweden in banning the use of amalgam in dental procedures, a move which at the time added weight to the anti-amalgam lobbyists’ argument here in the UK.

The scientists who conducted this most recent study say more investigation is needed to quantify and characterise mercury exposure from dental amalgam.

Prior to this report, little was known about how the chemical forms of mercury in dental amalgam might change over time.

The scientists caution that ‘human exposure to mercury lost from fillings is still of concern’.

To read the study, please click here.

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