Don't automatically assume a debtal school won't replace your amalgams. Some might, even if yours aren't in such bad shape.
Be prepared to possibly get a no answer, but perhaps you might be able to talk them into replacing at least some of your amalgams that are in worse condition. It depends on the individual school, and perhaps who examined you, how busy they are(and perhaps also if you are a paying customer rather than on medicare or medecaid?). Judging the condition of your amalgams may also be quite subjective. Perhaps a dental school might be willing to replace some but not all of your amalgams. It is worth a try, especially if they will give you a free or low cost consultation.