Here is a link with dry mouth info. Pain can be from mutiple factors including radiation, chemo injury, food injuries, mucosictis, bacterial, fungal, like thrush, and viral infections, which need to be treated with appropriate medication, impecable oral care, pain meds, changing type of foods etaen not to cause injury like non sharp textured, spicy, hot temperature, acidid foods.
http://www.oley.org/lifeline/Managing_the_Symptoms_of_Dry_Mouth.htmlGood luck
