Dental fillings with amalgam used to be very popular with dentists because of their very good filling properties.
However, these fillings consist of 50% mercury and can corrode over time. These small amounts of mercury can enter the body via the oral mucosa and cause allergic reactions.
Adding to the low health hazards is the visual aspect of amalgam fillings: The fillings are very dark and stand out in the bright tooth color.
Today, amalgam fillings have largely been superseded by other fillers. The existing fillings should be checked for tightness during regular checks at the dentist. Insufficient work should be replaced with modern fillers such as composites or ceramics.