Thanks Bryanna, the dentist didn't take an X-ray at the check up. It was my upper first molar and it wasn't root canalled. It had a crack in it, which made it sensitive when I was eating. I was offered a root canal and crown, or extraction. I remember your advice previously about root canals and decided to get it extracted instead.

I have no periodontal disease and my dentist has commented about how healthy my gums are. I've no root canals in any other teeth. I do smoke and I drink alcohol occasionally, but very little. I've had stomach problems with ulcers and GERD previously but it seems to be ok now. I'm not taking any medication. None of this has changed since the extraction.

I had stitches after the extraction and I know the dentist used gelfoam, which I heard can cause bad breath whilst it dissolves. But it's still just as bad 6 weeks on.
Should I ask the dentist to X-ray it again? He did take X-rays before extracting it to check if my sinus could be affected by the extraction. He said they showed it wouldn't.