They switched me from the trays to prescription Prevident with very high fluoride content. My teeth have taken quite a beating from the radiation. I've lost one tooth, had a root canal on #31 which was right in the radiation field (and I am having more problems with it) and have had pretty severe gum recession. I am meticulous in my dental care, Water Pik, woven floss, perio-aid, etc. Evidently the risk of ORN is less in persons who received IMRT or other targeted radiation. We'll see...