That's a tricky one! I thought all silver fillings had mercury content and I heard that the really toxic ones came from the 1970s which is exactly when I had mine put in. There is plenty of information available on the internet and my own dentist mentioned nothing to me other than he would have silver fillings removed if he had them. It was a costly trip to my dentist - in fact two visits, and he had all the up to the minute dams and this and that, electrickery, bells and whistles. It is a private practice in Camberley.
I was warned that not all dentists do this procedure with the correct bits and bobs to stop patients inhaling the very debris that is being removed, so ending up in a worse state.
Today I have just walked from my kitchen with a coffee full to the brim and haven't spilled a drop. Other little things like being able to get dressed without balancing myself with a free hand, being able to step into the shower unaided, walking down a dodgy staircase whilst carrying a case - all these things (and more) made it worthwhile for me. The best bit for me - I can stand for longer periods. I had just reached the stage where I had to sit more and more.
Any more I can tell you if you want to message me.