The American Dental Association says metal fillings have been used safely for more than 100 years and fresh government studies said they caused no problems in children.
However, Linda Brocato of Prospect Heights, Ill., is convinced metal fillings caused her to develop multiple sclerosis -- symptoms that improved when she had the fillings replaced.
"The FDA is supposed to protect us, and they have not done so in this instance," Brocato told the Chicago Sun-Times.
Brocato filed the Chicago suit behalf of herself, a California dental board member and an Arizona state senator, among others.
While the FDA banned mercury in disinfectants and veterinary products and warned against mercury in fish, "we fail to understand why the FDA ... continues to allow its unregulated use inches from a child's brain," they wrote U.S. Health and Human Services Secretary Michael Leavitt.
2014: The Year in Music [PHOTOS]