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Your Oral Health

Chemotherapy and Your Mouth

Are You Being Treated with Chemotherapy for Cancer?

While chemotherapy helps treat cancer, it can also cause side effects. Some of these problems affect the mouth and could cause you to delay or stop treatment - but there are ways to help decrease these problems so you’ll get the most from your cancer treatment. To help prevent serious problems, see a dentist at least two weeks before starting chemotherapy.

How Does Chemotherapy Affect the Mouth?

Chemotherapy is the use of drugs to treat cancer and other diseases. These drugs kill cancer cells, but they may also harm normal cells, including cells in the mouth. Side effects include problems with your teeth and gums; the soft, moist lining of your mouth; and the glands that make saliva, as well as an increased likelihood of cold sores and other mouth infections.  

It’s Important to Know Side Effects in the Mouth Can be Serious  

  • The side effects can be painful and make it hard to eat, talk, and swallow.
  • You are more likely to get an infection, which can be dangerous, when you are receiving treatment.
  • If the side effects are bad, you may not be able to keep up with your cancer treatment. Your doctor may need to cut back on your treatment or may even stop it.

What Mouth Problems Does Chemotherapy Cause?

The problems depend on the chemotherapy drugs and how your body reacts to them. You may have these problems only during treatment or for a short time after treatment ends.  
  • Painful mouth and gums
  • Dry mouth
  • Higher risk of cavities
  • Burning, peeling, or swelling tongue
  • Infection
  • Change in taste

Why Should I 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 is not 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 oncologist to talk to each other about your cancer treatment. Be sure to give your dentist your oncologist’s phone number.  

When Should I See a Dentist?

You need to see the dentist at least two weeks before your chemotherapy begins. If you have already started chemotherapy and didn’t go to a dentist, see one as soon as possible. You should also see a dentist as recommended or needed during and after treatment.  

What Will the Dentist and Dental Hygienist Do?  

  • Check your teeth and gums.
  • Take X-rays if necessary.
  • Take care of mouth problems - especially infected teeth which may cause problems later.
  • Show you how to take care of your mouth to prevent side effects.

What Can I Do To Keep My Mouth Healthy?

See a dentist before you start cancer treatment. Ask about whether you may need artificial saliva, fluoride, and/or other rinses. Once your treatment starts, look in your mouth every day for sores or other changes. These tips can help prevent and treat a sore mouth.

To keep your mouth moist:  

  • Sip water or sugarless drinks often.
  • Suck on ice chips.
  • Chew sugarless gum or suck on sugarless hard candy to stimulate saliva flow; citrus, cinnamon, or mint-flavored candies are good choices.
  • Use a saliva substitute.
  • Don’t use tobacco or alcohol. They dry out the mouth.
  • Use a humidifier at night.

To clean your mouth, tongue, and gums:

  • Check with your oncologist or dentist regarding any restrictions or changes to brushing and flossing.
  • Typically, you should brush your teeth, gums, and tongue with an extra-soft toothbrush after every meal and at bedtime. If brushing hurts, soften the bristles in warm water.
  • Floss your teeth gently every day. If your gums bleed and hurt, avoid the areas that are bleeding or sore, but keep flossing your other teeth.
  • Use fluoride toothpaste.
  • Use the special fluoride gel and/or other products that your dentist prescribes.
  • Don’t use mouthwashes with alcohol in them.
  • Talk to your oncologist or dentist about your dentures, because dentures that don’t fit well can cause problems.

If your mouth is sore or dry, watch what you eat and drink:

  • Choose foods that are good for you and easy to chew and swallow.
  • Take small bites of food, chew slowly, and sip liquids with your meals.
  • Eat moist, soft foods such as cooked cereals, mashed potatoes, and scrambled eggs.
  • Be aware that spicy, salty, or acidic foods may irritate your mouth.
  • Avoid drinks with caffeine, such as coffee, tea, and some sodas. Caffeine can dry out the mouth.
  • Stay away from sharp, crunchy foods which could scrape or cut your mouth.
  • Sip water or a sugarless drink during meals. This will make chewing and swallowing easier. It may also improve the taste of food.
  • Call your doctor or nurse when your mouth hurts. Work with them to find medicines to help control the pain. If the pain continues, talk to your oncologist about stronger medicines.

Do Children Get Mouth Problems Too?

Chemotherapy causes other side effects in children, depending on their age. Problems with teeth are the most common. Permanent teeth may be slow to come in and may look different from normal teeth. Teeth may fall out. The dentist will check your child’s jaws for any growth problems. Before chemotherapy begins, take your child to a dentist. The dentist will check your child’s mouth carefully and pull loose teeth or those that may become loose during treatment. Ask the dentist or hygienist what you can do to help your child with mouth care.  


  • Visit your dentist before your cancer treatment starts.
  • Take good care of your mouth during treatment.
  • Talk regularly with your oncologist and dentist about any mouth problems you may have.