If precautions can be taken, leaving the tooth in has advantages. For one, if the nerve base is not completely removed, it can be a source of chronic infection. Of course, drilling a filling does have the disadvantage of exposing someone to mercury.

Generally speaking, it good to save a living tooth when possible, but that has to be evaluated on a case-by-case basis.

In case this hasn't been mentioned yet, the red coloring in dentures often has mercury in it, so those have to be avoided or at the very least, checked for mercury.

I'm sorry this is such a complicated process, but the government has made it difficult for us by setting up one bad policy after another.