Like Donna, I have been helping my dentist support his family. No sooner was I done my first radiation and chemo TX then I had four root canals and four crowns. I was worried that I would or should get HBO but my prothodontist specializes in Head and Neck Cancer patients and was confident I didn't need it.
See about getting flouride trays, as most of us now use them for life. I had a nice break of about a year after the recurrence with zero food in my mouth reducing the chance of decay and the sensitivity of the post surgery tissue making the flouride burn. But the extra second round of radiation prompted the prothodontist to insist I start back up on flouride trays if I wanted to keep my teeth.
Just another example of how radiation is the gift that keeps on giving.