Mouth Care During Your Cancer Treatment

This information explains how to care for your mouth during cancer treatment.

About Mucositis

Some cancer treatments, including radiation therapy to the head and neck, may affect the cells that are in your mouth and digestive tract. This is known as mucositis.

Mucositis can cause redness, swelling, tenderness, and sores on the lining of your mouth, tongue, and lips. You may experience some mouth and throat discomfort that can make it hard to eat or swallow. These symptoms may begin 3 to 10 days after treatment starts. How quickly they go away depends on your immune system and the treatment you’re receiving.

Back to top Arrow (up) icon.Icon pointing upwards. Usually means that the containing element can be opened and closed.

Caring for Your Mouth During Your Cancer Treatment

Dental care

Your doctor may tell you to see a dentist before you start cancer treatment. If you need to see your dentist during your treatment, ask them to call your doctor at Memorial Sloan Kettering (MSK) first.


  • Brush your teeth and tongue gently after each meal and at bedtime. Use a small, soft-bristle toothbrush. If your mouth is too sore for a regular soft toothbrush, you can get a supersoft one from a drugstore. Some examples of these are:
    • Biotene® Supersoft Toothbrush
    • Sensodyne® Extra Soft, Gentle Toothbrush
    • Colgate® 360 Sensitive Pro-Relief Toothbrush, Compact Head, Extra Soft
    • Oral-B® Indicator 35 Compact Head Toothbrush, Soft
  • Change your toothbrush every 3 to 4 months or more often if needed.
  • Use a fluoride toothpaste or baking soda with fluoride.
  • If you have a set of dentures, a bridge, or a dental prosthesis, take it out and clean it each time you clean your mouth. You can keep wearing it if it fits well and does not irritate your mouth. Take it out of your mouth while you sleep. If you develop any irritation, keep it out of your mouth as much as possible.


Floss your teeth with unwaxed dental floss once daily at bedtime. If you have not flossed regularly before treatment, don’t start flossing now.


Rinse your mouth every 4 to 6 hours, or more often as needed. Use one of the rinses listed below:

  • One quart (4 cups) of water mixed with 1 teaspoon of salt and 1 teaspoon of baking soda.
  • One quart of water mixed with 1 teaspoon of salt
  • One quart of water mixed with 1 teaspoon of baking soda
  • Water
  • A mouthwash with no alcohol or sugar, such as Biotene® PBF Oral Rinse or BetaCell™ Oral Rinse.

Don’t use very hot or cold temperatures of mouth rinses.

Swish and gargle well for 15 to 30 seconds, then spit out the rinse.

If your nurse told you to irrigate your mouth, you will get other instructions about rinsing.

Moisturizing your lips

  • Use a lip moisturizer (such as, Aquaphor®, Vaseline®, Eucerin Original®, or A&D® ointment).
  • Do not apply lip moisturizers 4 hours before radiation therapy to the head and neck.
Back to top Arrow (up) icon.Icon pointing upwards. Usually means that the containing element can be opened and closed.

Managing Mouth Pain During Your Cancer Treatment

What to avoid

If you have mouth pain during your cancer treatment, you should avoid:

  • Tobacco
  • Alcohol
  • Commercial mouthwash that has alcohol (such as Scope® and Listerine®)
  • Salty foods and foods that contain strong spices (such as pepper, chili powder, horseradish, curry powder, and Tabasco® sauce)
  • Citrus fruits and juices (such as orange, lemon, lime, grapefruit, and pineapple)
  • Tomatoes
  • Hard, dry, or coarse foods (such as toast, crackers, raw vegetables, potato chips, and pretzels)
  • Very hot or cold foods and liquids

Managing symptoms

About medications

If you have a few small, painful areas, your doctor may prescribe an anesthetic (numbing medication), such as viscous lidocaine 2%. You can apply it to the painful areas using a cotton swab (Q-tip®). Apply it every hour as needed.

If you feel pain in most of your mouth and throat, your doctor may prescribe medication to coat your whole mouth (such as GelClair® or viscous lidocaine 2%). Swish, gargle, and spit out 1 tablespoon of the medication every 3 to 4 hours, up to 8 times a day. Do not swallow the medication. Do not eat for 60 minutes after using the medication.

If you still have mouth pain, tell your doctor or nurse. They may prescribe other medications for your mucositis.

Trouble swallowing

Here are some suggestions to help make swallowing easier. This will help you take in enough protein and calories during your treatment:

  • If your mouth is dry, rinse it just before eating to moisten it and stimulate your taste buds.
  • Eat warm or cool foods. Don’t eat very hot or very cold foods.
  • Eat soft, moist, bland foods in small bites and chew them well.
  • Use sauces and gravies.
  • Moisten foods with yogurt, milk, soy milk, or water.
  • Dip dry foods in liquids.
  • Blend or purée your food.
  • Avoid things that can irritate your throat such as alcoholic beverages, tart or acidic fruits and juices, spicy foods, pickled foods, and tobacco.
  • Sip plenty of water throughout the day to be sure you have enough liquids. Keep in mind that drinks with sugar (juice, iced tea, soda) may cause tooth decay. You can drink these during meals, but limit them between meals.

Dry mouth

To manage dry mouth, drink sips of water often throughout the day. You can also use:

  • A spray bottle to squirt water into your mouth
  • Over-the-counter mouth moisturizers (such as Biotene® Oral Balance, Salivart® Oral Moisturizer, Mouth Kote® Dry Mouth Spray)
  • Biotene® Gum
  • A humidifier in the room that you’re in

Trouble eating

You may have trouble eating due to your mouth pain. If you do, here are some suggestions to make sure you are getting all the nutrients you need.

  • Tell your doctor and nurse if you’re not eating well. They may arrange for you to see a dietitian.
  • Drink nutritional supplements such as Carnation® Instant Breakfast and Ensure®.
  • Add protein powders to broths, soups, cereals, and beverages.
  • Eat multiple small meals throughout the day rather than fewer large meals. Try having a small meal every 2 to 3 hours.
Back to top Arrow (up) icon.Icon pointing upwards. Usually means that the containing element can be opened and closed.

Call Your Doctor or Nurse if You Have:

  • A temperature of 100.4° F (38° C) or higher
  • New redness, sores, or white patches in your mouth
  • Bleeding of your gums or mouth
  • Difficulty or pain when you swallow
  • Pain that does not get better with pain medication
  • Any questions or concerns
Back to top Arrow (up) icon.Icon pointing upwards. Usually means that the containing element can be opened and closed.

Last Updated