FDA now states, for example:

“Dental amalgams contain mercury, which may have neurotoxic effects
on the nervous systems of developing children and fetus.” “Pregnant
women and persons who may have a health condition that makes them
more sensitive to mercury exposure, including individuals with
existing high levels of mercury bioburden, should not avoid seeking
dental care, but should discuss options with their health practitioner.”

For the FDA statement here
Toxic Teeth is a grassroots organization dedicated to mercury free dentistry, check them out for additional information.