Mercury Fillings May Be Less Toxic: Caution Still Needed

A new study on the surface chemistry of silver-colored, mercury-based dental fillings suggests that the surface forms of mercury may be less toxic than that which was previously thought.

Graham George and his colleagues note that mercury-based fillings (amalgams) have been used by dentists to repair teeth for over 100 years. In recent years, their use has become controversial because of concerns about exposure to potentially toxic mercury. Even so, mercury can potentially exist in several different chemical forms, each with a different toxicity.

Scientists analyzed 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. Aged fillings, on the other hand, usually contain a form of mercury, called beta-mercuric sulfide or metacinnabar. This form is unlikely to be toxic to humans.

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 certain foods, exposure to dental hygiene products, or some other causes.

Even so one should be cautions as exposure to mercury as it changes chemical forms over time is still a concern.

George et al. The Chemical Forms of Mercury in Aged and Fresh Dental Amalgam Surfaces. Chemical Research in Toxicology, 2009; 22 (11): 1761 DOI: 10.1021/tx900309c

2 thoughts on “Mercury Fillings May Be Less Toxic: Caution Still Needed”

  1. Do you think the mercury just ‘evaporates’ into the atmosphere? Solids dont evaporate, and being located in the mouth, if there is less mercury over time, the mercury certainy went into the body didn’t it. You’re either doing cover up for the ADA or you’re insanely stupid.

  2. Great comment Phil. This particular study was actually done in Canada.

    I did not write this study and really never should have published the results on this blog as clearly the mercury in question is going into the body.

    A major problem today is news organizations just picking up science results without asking questions.

    The whole point of this website is to ‘make you think twice before wisdom teeth removal’ so obviously I am encouraging a strong hope that people will ask questions and not be intimated by someone who may hold a degree and appear to have more knowledge than them.

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