Steve

After my first 40 IMRT, my prosthodontist told me I needed a root canal on the wisdom tooth that had been directly in the path of the radiation. His assessment was that an extraction would put me at risk for radiation necrosis but not a root canal. The oral surgeon had wanted to pull it, but my prosthodontist intervened. That was two years ago and all is still fine. I hope you have a similar good experience.
I just had new uber X-ray/CT scan of my jaw done last month and it showed no necrosis - although I was amazed at all the staples left behind from surgery to "mark' the tumor as well as the size of the titanium plate that holds my jaw together now. I actually had another root canal done also and no problems but that one was only in the "scatter radiation (?)" zone. Zero problems
Best wishes
Charm