How safe are the silver fillings in your teeth?
A panel of experts have begun a two-day meeting on the issue at the Food and Drug Administration.
Dentists have been filling cavities with amalgam fillings for decades.
They're a combination of metals, including mercury.
Mercury is a poison, but the question is whether it poses a health risk in the form of dental fillings, which release a small amount of mercury vapor.
Dr. Ada Cooper is a spokeswoman for the American Dental Association.
"Amalgam is not only safe and effective but it's an extremely important option that patients should have," she says.
Amalgam fillings are often the cheapest and longest-lasting option, but some blame them for health problems.
Freya Koss developed severe double vision and balance problems in 1998.
Doctors first thought she had multiple sclerosis or lupus, then turned their attention on an amalgam filling she'd recently had.
They suspected "acute mercury toxicity" and removed 12 fillings.
"Mercury is still somewhere in the body, but I am, I would say 98% improved without having those mercury fillings in my teeth," she now says.
Koss will tell her story to the to the fda panel of experts during its two day meeting.
The FDA committee will not make any specific recommendations related to amalgam fillings, but will discuss a series of questions regarding safe levels of mercury exposure.