I completely understand, I am sensitive also. And very ill and I don't have amalgams anymore, but I "was' healing at one point. Just too many other issues occured and I'm now pretty much permanently ill. Not sure what they are but possible jawbone cavitations from wisdom tooth removal coudl be part of it. Plus my ongoing problem with candida.

At any rate, I see how careful you have to be. There is something you could do. You can get a sample of the material (plus the bonding material they use to seal it) and do a cheek and gum test. You just basically get a sample, put it in your mouth everyday and just pretty much suck on it, or leave it in your mouth for as long as you can (taking it out when eating or sleeping) and do this for about two weeks or something and see if there is any reactions.

This is just another way you can test. Plus you may want to look at getting a good porcelain restorative instead of composite. One such good one is Cerec porcelain and apparently they don't "leach" out their components like amalgam and composite. Though again, I'd advise the cheek and gum test with that too.

Whatever you do, I sincerely hope something works out for you. Treading carefully is very wise.

take care and all the best.