"Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Approximately half (50%) of dental amalgam is elemental mercury by weight. The chemical properties of elemental mercury allow it to react with and bind together the silver/copper/tin alloy particles to form an amalgam."
Amalgam fillings do offgas tiny amounts of mercury. Of course, this is a controversial topic and there's a lot of misinformation around, so do your own research. Personally, I came to the conclusion that the one amalgam filling I have is ok but too many would cause potentially toxic buildup over a lifetime so I'll never get another.
"Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Approximately half (50%) of dental amalgam is elemental mercury by weight. The chemical properties of elemental mercury allow it to react with and bind together the silver/copper/tin alloy particles to form an amalgam."
https://www.fda.gov/medical-devices/dental-devices/dental-am....