Horrible taste in my mouth - could it be my filling?

[LadyGaggia]

Last day or so I have noticed a weird waft coming from the lower back teeth on my left side.
It leaves me with a nasty taste that I can't identify...bleugh.

The dentist mentioned that I may have to have a filling replaced and I wondered whether this was what was causing the taste...

Any ideas? How did you know when you needed a new filling anyway?

Ta!

Inspect your tonsil beds with a torch. The little crevices can fill with food debris and give off a horrible taste.

Ooh, ewwww.

Thanks, I will inspect later tonight when I brush my teeth.