The amalgam has 20 to 35 percent sliver, while mercury accounts of half of its weigh. Other compounds found in it are tin, copper and zinc. Dental fillings made of it have gained their popularity thanks to their low price and extended durability.

The FDA has previously checked and approved mercury dental fillings, but said that while there is a very small chance of people having health problems as a result of them, more research would be necessary to completely rule out the case.

The results of the next study that the FDA plans to make on amalgam will be published next year. Specialists predict that most probably the agency will neither ban the product, nor ask for a specific labeling stating that it is harmful to certain categories of people. Instead FDA will try to set a series of rules for the companies that are producing it, so that people’s health would be perfectly protected.

The agency has said that it does not encourage people to change their mercury dental fillings. However, it recommended that people with a lower tolerance to mercury as well as pregnant women should announce this to their dentists and see if alternatives are possible.