There's lead from dental fillings though.

Mercury? There is no lead in dental filings. In fact, filings are mercury free as of the last couple of decades.

In some places, yes. If you get the silver/gray stuff, it's about half mercury.

I think lead was used in dental amalgams but I don't know when it was phased out. But yeah, mercury too.

The word "amalgam" means a mixture of mercury with another metal. A lead amalgam would be too soft to use as a chewing surface (it would have a texture like chewing gum). Traditional dental amalgams were mixtures of silver or gold and mercury.

You are right, I probably misremembered what I've read.