I have searched, but the threads were from 2008-10 mainly and nothing in the last three years.
I had a filling come out about 10 years ago. I go yearly every couple of the years to see the dentist and they have always said its fine and up to me if I want it replaced.
I've always said just leave it. However I am getting increasingly annoyed about having to dig food out of there every time I eat (rasberrys or air dried beetroot crisps are the worst).
So I've bit the bullet and asked them to repair it, however they've said as its a back tooth it will have to be grey filling. 
I'm probably being paranoid, but should I be concerned about this? I'm tempted to just leave it as even psychosomatically it may make me unwell