Mouth Care During Your Cancer Treatment

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

What changes will I experience to my mouth and throat during treatment?

Some medications to treat cancer and 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 difficult 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 are receiving.

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Do I need special 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 him or her to call your doctor at Memorial Sloan Kettering Cancer Center (MSK) first.

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How should I care for my mouth during treatment?


  • 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. 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, do not start flossing now.


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

  • One quart (4 cups) of water mixed with 1 teaspoon of salt and 1 teaspoon of baking soda. This is the same as 1 quart of normal saline mixed with 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.

Swish and gargle well for 15 to 30 seconds, then spit out the rinse. Adjust the temperature of the solution for comfort, but avoid extreme hot or cold temperatures.

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

Moisturizing your lips

Use a lip moisturizer (e.g., Aquaphor®, Vaseline®, Eucerin Original®, or A&D® ointment) after mouth care. Do not apply it 4 hours before radiation therapy to the head and neck.

Should I avoid anything?

Yes. You should avoid:

  • Tobacco
  • Alcohol
  • Commercial mouthwash that has alcohol (e.g., Scope®, Listerine®)
  • Salty foods and foods that contain strong spices (e.g., pepper, chili powder, horseradish, curry powder, Tabasco® sauce)
  • Citrus fruits and juices (e.g., orange, lemon, lime, grapefruit, pineapple)
  • Tomatoes
  • Hard, dry, or coarse foods (e.g., toast, crackers, raw vegetables, potato chips, pretzels)
  • Very hot or cold foods and liquids
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What should I do if I have mouth pain?

Tell your doctor or nurse. If you have a few small, painful areas, your doctor may prescribe an anesthetic that you can apply to the area. An example of this is viscous lidocaine 2%. You can apply it to the painful areas using a swab or 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. He or she can prescribe other pain medications.

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What should I do if I have trouble swallowing?

Here are some suggestions to help make swallowing easier and 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.
  • 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 irritants 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.
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What should I do if I’m not eating enough?

  • Drink nutritional supplements such as Carnation® Instant Breakfast and Ensure®.
  • Add protein powders to broths, soups, cereals, and beverages. Dilute these as needed.
  • Eat multiple small meals throughout the day rather than fewer large meals. Try having a small meal every 2 to 3 hours.
  • Tell your doctor and nurse if you are not eating well. They may arrange for you to see a dietitian.


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What should I do if my mouth is dry?

Drink sips of water often throughout the day, or use:

  • A spray bottle to squirt water into your mouth
  • Over-the-counter  mouth moisturizers (e.g., Biotene® Oral Balance, Salivart® Oral Moisturizer, Mouth Kote® Dry Mouth Spray)
  • Artificial saliva
  • Biotene® Gum
  • A humidifier in the room that you’re in
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When should I contact my doctor or nurse?

Contact your doctor or nurse if you have:

  • 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
  • A temperature of 100.4° F (38° C) or higher
  • Any questions or concerns
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