Dear Fran,
I think no matter what type of treatment you decide upon, once you have cancer, it seems your life will change. You are young, you have a full life ahead of you. My mom has gone through 31 treatments of IMRT, 8 cycles of Erbitux and just this past week brachytherapy surgery. I can tell you that her saliva is still pretty good. There are many products on the market that are beneficial in aiding saliva, Biotene for one, my mom still prefers the sodium chloride she gets from her doctor. As for the dental end of it, you could get your teeth taken care of before hand, any damage or teeth that need to be replaced could be dealt with after. We have two dentists here at OCF, Jerry Wilck and Dr. Mike, who can shed a lot of light in this area.
Fran, I can't imagine wondering what if I didn't try this if some of the doctors are feeling so strongly about you following through this way. My mom was originally supposed to have similar surgery to yours but because of a heart condition which she was unaware of she had to go in a different direction. All along the doctors felt she would benefit from the radiation after surgery had she been able to go that route.
Read here and ask questions. So many dear people have helped so many, you just might find the answer you are searching for. Good luck to you, try to calm down, and I hope you find peace in whatever your decision is.
Donna