I'm not quite sure what material you're talking about that you put over a filling but you should see your dentist to make sure your teeth are protected. The medication could be causing the erosion but not too sure without seeing it. There 's no scientific evidence that i know of that amalgam fillings cause autoimmune disorders. You should consult your dentist with your symptoms, especially if you think you have an infection.
I do not agree with their opinion. I believe, from personal experience, Amalgam fillings should never be put in the mouth. Mercury inhibits your body from functioning properly and therefore leaving you open to many more health problems you may be predisposed to. Mercury can leak into the body with simply eating hot foods, being near computers screens that emit a low radation, along with power lines and more. It is amazing to see that what we put in our mouth affects our over all health.