My understanding is that the hair test isn't great for mercury. You need a challenge test-go see a doc that actually does them.
I would also be surprise if you don't have metal in your mouth. Look at the xray-metal shows up-If for some reason you have two different kinds of metal then your dds made an electronic current. Ask any first year Science student-two different metals in a salient solution-creates current-three intches from brain.
So there are a couple things you may want to look into