Oral HealthSide-Effects Management Dental hygienist Kris Potts breaks down the side effects, such as dry mouth and oral ulcers associated with cancer treatments and lists treatments available to combat these problems. Founding Member of the National Network of Healthcare Hygienists Fort Worth, Texas Among the many side effects associated with cancer treatments, 2 of the most common that often affect the mouth are dry mouth (called xerostomia) and oral mucositis (or painful oral lesions).