The US Food and Drug Administration (FDA) will review the scientific evidence which claims that mercury in dental amalgam does not cause harm to patients.

Dental amalgam is dental restorative material used for dental fillings, which contains a mixture of mercury and other metals.

In July 2009, FDA had classified amalgam as a moderate-risk item that released levels of mercury not high enough to cause harm in patients.

However, consumer and dental activists have petitioned to the agency about the possible link between mercury in dental amalgam and neurological and other health problems.

As a part of the review, an advisory panel will meet and discuss a series of technical questions about how exposure to mercury is measured, whether safe levels of exposure have been set correctly and the reliability of studies of mercury on humans.

FDA Center for Devices and Radiological Health deputy director for Policy Nancy Stade said the review is not being taken because of new data, and at this time, the FDA is not modifying its existing guidance that mercury fillings are safe.

"But questions about the rigor of the FDA’s science, contained in four petitions to the agency, justify a second look at the evidence," Stade said.