I have to say I did seem to notice that older fillings in particular seemed to come out more often after oil pulling. Nothing drastic and I could be wrong, but that's also my impression.
Crowns, gold fillings, no. Since it seemed limited to the infamous mercury laced Amalgam
fillings, I was fine with it. But Amalgam
fillings aren't designed to last more than 15 years so I think most of them were past their natural life anyway. Se la vie!