My husband is also getting close to that five year mark and has been trying to take good care of his teeth with frequency cleanings etc. He just had radiation treatment for the cancer. He had one root canal and one extraction on April 12 and April 13, 2011. He went through 20 hyperbaric treatments before them and 10 after at for 2 hours per day + about another 2 hours per day travel time and at a cost of $2,000. per treatment. Now three months later he has an infection and is on his second round of antiobiotics. The hyperbarics is supposed to help the mouth heal properly after the extraction. Just make sure your dental people are aware of your oral cancer history and also that they do adequate follow up afterwards since we thought Michael was doing well, but now he has this infection. You are right about the long term after effects of cancer and the treatment being no fun.