Trays - One comment I've heard about fluoride trays is they may not be all that effective at minimizing dental cavities in post rad patients.

The rational goes most of post rad tx cavities hit along the gumline. The trays put fluoride on the top surface of the tooth so it might not be helping the area of cavity formation.

Where I am on this topic is to focus primarily on the teeth along the gumline and the gums themselves, rather than the other parts of the teeth. My routine is to brush first with a regular toothpast, then waterpik thoroughly, then come back with a brushing using prescription fluoride paste. Leave it in my mouth then proceed to bed.