Hi Kathy, I agree with Joanna, as far as I know, there was no mention about carbonated beverages being a risk-factor for oral cancer, although one could get into a debate about the aspects of "artificial sweeteners" in diet beverages/foods that some say could lead to forms of cancer. I know topics such as this has caused much conversation in the past - and I don't want to rehash that if possible. Anyways - getting back to your question, carbonated beverages WILL sting for ahwile, at least I know it did for my husband while he was going through radiation and for a good 2 or 3 months afterwards. Now he is going on 7 months post-radiation, and MOST soda's don't bother him now -except for a few every now and then. It's also weird because sometimes he can tolerate certain spices and condiments like ketchup but other days - it still stings. It's a mystery to me. But like Joanna said, everyone heals at a different rate - so only time will tell. Good luck and sending best wishes and positive thoughts your way.