One way in which people are routinely exposed to extremely small amounts of mercury is through the gradual wearing-away process of dental amalgam fillings, which contain approximately 50% mercury. The amount of mercury to which a person might be exposed from dental amalgams would depend on the number of amalgams present as well as other factors.

The U.S. Centers for Disease Control and Prevention (CDC) has determined that dental amalgam fillings do not pose a health risk, although they do account for some mercury exposure in those having such fillings.

People who frequently grind their teeth or often chew gum can add to the small amount of mercury normally released from those fillings over time.

Note the process of removing mercury amalgam fillings generates mercury vapor and blood concentrations will subsequently rise substantially before they eventually decline. (1)

REFERENCES

¹(Kingman A, Albertini T, Brown LJ. Mercury concentrations in urine and whole blood associated with amalgam exposure in a US military population. J Dent Res 1998;77:461)