I didn't (not do I now) have dental insurance when my Amalgams were removed.
I believe you can get conventional insurance to pay if:
(1) You are "diagnosed" with mercury toxicity from the fillings, or
(2) The fillings have cracked and need to be replaced.
Either way, I don't regret dishing out over $2000 for the procedure because it is the turning point of my life. It's hard for anyone to understand the difference it can make in your life both physically and emotionally.