For patients who are undergoing oral radiation, I find that FL trays are hard to manage. First some do not tolerate the taste (taste perception changes during this time for some) and the mucositis makes it hard to use. I recommend my patients to use brush on flouride instead. It does two things. First, it MAKES you brush your teeth. Second, no clumsy annoying trays when your mouth is so tender. So speak with your dentist to see about this recommendation. Also getting proper nutrition is very important. I always tell my patients to drink supplemental drinks. If they find that the whole thing tastes so bad because of the altered taste thing, use the straw to bypass the tougue. Hope this helps. DP