I think there are some dentists that will give you a choice. Mine did, but I let him choose based on my Serum Compatibility test.

Don't be discouraged by quackwatch's demonization of these tests. Quackwatch is nothing more than a pharmaceutical disinformation website, as is the NCAHF.

Anyway, all dental filling types fall into broad categories:

BIS GMA (estrogen-enhancing - cancer)
Methyacrylate (hard on kidneys)
Ceramic (contains ~25% aluminum)
Gold (high copper content)
Resin (contains plastics and glass)
and more.

It may be good for me to put together a page describing all of the categories along with their advantages and disadvantages.