Radiation that affects the salivary glands can cause dry mouth (called xerostomia). You may have "tacky" saliva, an ongoing need to drink, challenges eating and speaking, and a decline in oral and dental health. Dry mouth increases your risk of cavities, requiring proactive oral hygiene at home, regular dental exams, and possibly, fluoride treatments. You may be able to use saliva substitutes in the form of gels, sprays or rinses or the prescription, Salagen. Try sugar-free lozenges or gum.