Chemotherapy and Your Mouth

young woman with shaved head smiling with teeth at cell phone

Are you being treated with chemotherapy for cancer?

While chemotherapy helps treat cancer, it often causes many side effects. Some of these problems impact the mouth and could cause you to delay or stop treatment.

To help prevent serious problems, it is recommended to see a dentist one month before starting chemotherapy.

How does chemotherapy affect the mouth?

Chemotherapy drugs kill cancer cells, but in the process, they also harm normal cells. This leads to various side effects, including problems with your teeth and gums, and the glands that make saliva (spit).

Side Effects

Chemotherapy side effects vary from person to person. You may have these problems only during treatment, or for a short time after treatment ends. Chemotherapy medications can hurt and make it hard to eat, talk, and swallow.

You are also more likely to get an infection, which can be dangerous when you are receiving cancer treatment. If the side effects are severe, you may not be able to keep up with your cancer treatment. Your doctor may have to cut back or discontinue your treatment.

These are the most common side effects associated with your mouth:

  • painful mouth and gums
  • dry mouth
  • burning, peeling, or swelling tongue
  • tooth or gum infection
  • altered taste

Why do I need to see a dentist?

If you go to the dentist before chemotherapy begins, you can help prevent serious mouth problems. Side effects often happen because a person’s mouth isn’t healthy before chemotherapy starts. Not all mouth problems can be avoided, but the fewer side effects you have, the more likely you will stay on your cancer treatment schedule.

It’s important for your dentist and cancer doctor to talk to each other about your cancer treatment. Be sure to give your dentist your cancer doctor’s phone number. 

Try to see a dentist about one month prior to the start of your chemotherapy treatment. This will allow for enough time for your dentist to complete any necessary treatment. If you have already started chemotherapy and didn’t go to a dentist, see one as soon a possible.

What steps can I take to keep my mouth healthy?

There are many ways to keep a healthy mouth during chemotherapy treatment. The first step is to see a dentist before you start cancer treatment. Once your treatment starts, it’s important to look in your mouth every day for sores or other changes. These tips can help prevent and treat a sore mouth:

Keep your mouth from drying out

  • frequent sips of water
  • suck ice chips
  • use sugarless gum or sugar-free hard candy
  • use a saliva substitute to help moisten your mouth
  • increase your water consumption

Clean your mouth, tongue, and gums

  • brush your teeth, gums, and tongue with an extra-soft toothbrush regularly, especially before bed
  • use a fluoridated toothpaste
  • soften bristles in warm water before brushing
  • avoid and alcohol based mouthwash
  • be gentle while flossing
  • use a rinsing solution of 1/4 teaspoon of baking soda and and 1/4 teaspoon of salt in one quart of warm water, followed by a plain water rinse multiple times a day
  • make sure your dentures fit well

How to help with a sore mouth

  • choose foods that are good for you and easy to chew and swallow
  • take small bites of food, chew slowly, and include liquids with every meals
  • eat softer foods, such as soups, mashed potatoes, or smoothies
  • if you have trouble swallowing, soften your food with gravy, sauces broth yogurt or other liquids.


  • crunchy foods that could scrape or scratch your mouth
  • spicy, or acidic foods, like citrus fruits and juices, which can irritate your mouth
  • sugary foods like candy or soda that increase your risk of cavities
  • toothpicks or other oral care aids that may cut your mouth
  • any alcohol or tobacco products

Three things to remember!

If possible, make an appointment to see your dentist BEFORE your cancer treatment begins

DURING treatment, continue taking care of your mouth the best you can.

Stay in contact with your dentist and your doctor, and discuss ANY mouth problems you may have.


National Institute of Dental and Craniofacial Research, Center for Disease Control and Prevention,. Department of Health and Human Services, National Institute of Nursing Research, National Cancer Institute

Photography: Antony Shkraba, Shvets Production, Pexels