Mouth care | Cancer Research UK
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When mouth care is important

It is important to keep your mouth very clean and moist

  • During cancer treatment
  • If you are not eating and drinking normally
  • If you are at risk of infections

General mouth care

  • Let your doctor or specialist nurse know if your mouth is getting sore - they can prescribe medicines to help
  • Clean your mouth and teeth gently every morning and evening, and after each meal
  • Use a soft bristled or child's toothbrush
  • If your toothpaste stings, or brushing your teeth makes you feel sick, use alcohol free mouthwash instead
  • You can use dental floss gently every day (if your doctor agrees) but be careful not to harm your gums
  • If your mouth is very sore, your doctor or specialist nurse can prescribe mouthwashes containing local anaesthetic
  • If you wear dentures, take them out and clean them every morning and evening, and after each meal
  • Use lip balm to keep your lips moist
  • If you are not eating or drinking normally, you need to moisten your mouth at least every 2 hours with mouthwash or a foam mouth care stick dipped in mouthwash

Remember to tell your doctor or nurses straight away if you start to get any mouth problems.


Support from your doctor, nurse or dentist

If you are due to have radiotherapy to your mouth, your doctor may advise that you see your dentist for a check up at least 2 weeks before treatment begins. Your dentist can check whether you have any tooth decay or gum problems, and will treat these before you begin your radiotherapy.

Your doctor or specialist nurse may give you one or more alcohol free mouthwashes to use every 4 hours while you are having treatment. This is mainly to help stop infection. You may have anti fungal lozenges, drops or mouthwashes too. It is important that you try to remember to use these as prescribed.

If you have a very sore mouth, your doctor may give you a mouthwash that contains local anaesthetic. You use it several times a day. Ask your doctor about it if you think it might help you. You can also have painkillers. Some people have morphine drips (infusions) because their mouths are so sore, so do let your doctor or nurse know if your mouth is painful.



Dentists recommend flossing for keeping your mouth fresh and clean. But it can damage the gums.

Blood cells called platelets are important for blood clotting. But people having chemotherapy can have a low platelet count. This is particularly likely with the high dose courses of chemotherapy for leukaemia or lymphoma.

If you have a low platelet count because of chemotherapy, your doctor may not want you to use dental floss because it can make your gums bleed. So do check with your doctor or specialist nurse first. There are alternatives, such as inter dental toothpicks or gum stimulators (rubber tips). But do be careful with these too. Sticking anything in between your teeth can cause gum damage and if your gums are bleeding, there is an open pathway for infection to get in.


Coping with a dry mouth

Some cancer drugs, painkillers, and mouth radiotherapy can make your mouth dry. After radiotherapy to the head, some people can have a permanently dry mouth. Your mouth also may be dry if you are not eating or drinking properly because you are not well enough. The following tips won't apply to all these situations, but just pick the ones that might work for you.

  • Choose meals that are moist
  • Use gravies and sauces to make swallowing easier
  • Take regular sips of water with your meal to help you chew and swallow your food
  • Try to drink at least 3 pints (one and a half litres) of fluid a day
  • Milk, water, fruit or vegetable juices are the best drinks to choose, but any fluid is better than nothing
  • Suck ice chips to refresh your mouth
  • Chew sugar free chewing gum
  • Eating fresh pineapple can keep your mouth fresh and moist, but avoid acidic fruits (such as oranges, grapefruit) if your mouth is sore
  • If you want to drink citrus juices, dilute them with water so they are not as acidic
  • If you are making some saliva, ask your doctor about medicines to stimulate your salivary glands
  • If you aren’t making any saliva, talk to your doctor about artificial saliva products - there are tablets, mouthwashes, gum, pastilles, and toothpaste
  • Artificial saliva can help you to feel better and can help to prevent tooth decay and mouth soreness
  • If there is no obvious reason for your dry mouth, talk to your doctor or nurse about your medicines you are taking - some drugs cause a dry mouth

Coping with taste changes

Food and drink can taste strange when you are having some chemotherapy drugs. Radiotherapy to the mouth may permanently change your sense of taste. This may improve slowly over time. If you have had any treatment that affects your sense of smell, this will affect your sense of taste. Many of us don't realise, but the scent of food contributes a great deal to how it tastes. 

If you have taste changes

  • Avoid foods that taste strange to you, but try them again every few weeks as your taste may have gone back to normal
  • Choose foods that have strong flavours (such as herbs, spices and marinades) if all your food tastes the same.
  • Try adding garlic, lemon juice, herbs and spices to food.
  • You can marinate foods overnight, but if you haven't got that long, leave it for however long you've got - even 10 minutes will make a difference.
  • Make a marinade with a couple of tablespoons of olive oil, and whichever herbs or spices you fancy - add a splash of wine or some lemon juice if you like.
  • You can use a dry marinade, which is sometimes called a rub - mix up spices and herbs and slap onto uncooked meat or fish with clean hands
  • Be careful with spicy foods if you have a sore or infected mouth
  • Gravies and bottled sauces can help to add flavour to a meal
  • You might find you prefer stronger versions of your favourite foods - smoked ham or bacon or stronger cheese.
  • You may prefer to avoid your favourite foods and drinks altogether during chemotherapy so there is no danger of going off them for good - this is particularly useful advice for children

Coping with bad breath

Many things can cause bad breath. It can be worse if you also have a dry mouth. But good mouth care can cure most cases of bad breath. 

To help treat bad breath

  • Brush your teeth regularly
  • Floss daily (if your doctor agrees)
  • Use mouthwashes after cleaning your teeth or after eating
  • Chew sugarless gum or suck on sugarless mints
  • Drink plenty of water to keep your mouth moist - swish the water around in your mouth for a few seconds to help remove any bits of food that may be stuck in your mouth or teeth.
  • Have regular dental check ups

Preventing mouth sores and infection

If your type of cancer drug tends to cause mouth sores, you need to try to prevent getting mouth infections. A dry or sore mouth can easily become infected.

  • Check your mouth every day for sores or any other changes
  • Tell your doctor or nurse if there are any problems
  • Stick firmly to your mouth care routine, cleaning morning and night and after every meal
  • Use anti fungal or other mouthwashes your doctor has prescribed, even if you don't like them. They may suggest rinsing your mouth regularly with plain water or salt water
  • A salt water mouth rinse can help to stop bacteria growing - use 1 teaspoon of salt in 1 pint of cold or warm water. You can use this during the day as part of your mouth care routine. You'll need to make a fresh supply every day
  • Stay away from foods that are sharp or crunchy which could scrape or cut your mouth - such as crisps or French bread.
  • Avoid alcohol (especially neat spirits), smoking, and using toothpicks - these irritate the lining of your mouth and may make problems worse
  • Some people say that sage, thyme and German chamomile help reduce soreness and prevent infection - steep a teaspoon of dried sage, thyme, or 2 tablespoons of German chamomile flowers, in a cup of boiling water for 20 minutes, strain and cool, and use as a mouthwash several times a day
  • If you are taking ginger to help with sickness, this may help your mouth - some people believe that ginger helps soothe inflammation
  • Sucking crushed ice during chemotherapy sessions can lower the risk of mouth ulcers by reducing blood flow to the mouth - you must talk to your doctor before trying this

If you have mouth ulcers or infection

If you have sores in your mouth (ulcers) or infection, your nurse will give you a mouth care routine to follow. You may have mouthwashes or medicines to help protect the lining of your mouth, reduce pain, and keep your mouth clean. Your doctor may prescribe anti fungal mouth rinses to help stop thrush infection. It is important to take your medicines and use the mouthwashes exactly as your doctor or nurse advise.

  • Brush your teeth regularly with a soft toothbrush using alcohol free mouthwash - a baby’s toothbrush is good
  • If your mouth is too sore for a toothbrush, you can clean your teeth with a foam mouth care stick or a piece of gauze dipped in the mouthwash - ask your nurse for advice.
  • If you have sores in your mouth that are crusty, rinse with mouthwash several times a day to loosen the crusts
  • You could try a gel mouthwash that sticks to the inside of your mouth and reduces pain from mouth ulcers - ask your doctor or nurse about these
  • If you are able to eat, choose bland, soft foods, such as mashed potato, well cooked rice, or scrambled eggs
  • Don't eat spicy or salty foods, dry or crisp foods, citrus fruits or juices
  • If you can't eat, it is important to drink plenty of liquids - water is fine
  • It is much better to take painkillers and be able to eat and drink than to try to carry on without
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Updated: 31 July 2015