A patient has decay in tooth that means existing amalgam filling must be
removed.

Many dentists just drill it out thus aerosolizing toxicologically
massive amounts of mercury which the patient breathes into his lungs and
most dentists say amalgam placements are safe?

It would be funny if dentists weren't so dumb/stupid/careless.

Sure some dentists use a dam but i've never heard of one doing so in my
town and when i asked i received a quizzical look from the the idiot
in the green mask.