I had several extractions before radiation in 2011, but not after. I was supposed to have one extracted, and did 30 HBOT in 2011 for an impacted, abscessed tooth, but was hospitalized for a transfusion, and a recurrence one after the other, so I never did have it extracted. I currently need all my teeth extracted, and was waiting for cancer clearance, which I received today, and my RO said for sure I need to have HBOT, but I had much more radiation than most did, and recently finished one treatment in January.

If they can do root canal instead, it may better, I was told by a dentist. I didn't need HBOT for any root canal after radiation.

Yes, look at whether root canals may be an option.
Kris has 1 tooth left to go, then all his teeth will have been root Canalled . We chose this over extraction and particularly HBO. Neither of us were keen to do HBO at this stage. Really feel that we want Kris to be some years down the track before risking growth of any stray Ca cells left - if any.
Fortunately our public health system has done all this work for Kris.
Tammy