The U.S. Food and Drug Administration (FDA) has developed graphics that provide a visualization of recommendations about the use of dental amalgam (a mercury-containing dental restorative or filling material) in certain groups of people who may be at greater risk for potential harmful health effects of mercury exposure. 

These higher-risk groups are:

• Pregnant women and their developing fetuses
• Women who are planning to become pregnant
• Nursing women and their newborns and infants
• Children, especially those younger than six
• People with preexisting neurological disease
• People with impaired kidney function
• People with known heightened sensitivity (allergy) to mercury or other components of dental amalgam.