Looking after your mouth during radiotherapy

It is important to look after your mouth while you are having radiotherapy.

Radiotherapy can reduce the amount of saliva you make, which increases the risk of tooth decay. Keeping your mouth as clean as possible will help protect your teeth.

See your dentist and hygienist regularly. They can show you how to keep your mouth and teeth clean, and pick up any problems early. Fluoride gel and mouthwashes can help.

Looking after your mouth will help your mouth heal during and after radiotherapy. You can take painkillers to help with any soreness. Tell your doctor if you are still in pain, in case you need stronger ones or treatment for an infection.

Choosing your food carefully can help avoid discomfort and reduce the risk of tooth decay. If you are having problems eating, there are products and treatments that can help you get the nutrition you need.

Although these side effects are unpleasant, most people find they improve and gradually go away after treatment is over.

Coping with mouth problems during radiotherapy

It is very important to look after your mouth during and after radiotherapy. Keeping your mouth as clean as possible can help protect your teeth, encourage tissue healing and reduce the risk of problems in the future.

Caring for your mouth during radiotherapy

Radiotherapy to the head and neck often reduces the amount of saliva you can make. Saliva washes your teeth and protects them from decay. This means you’ll be more prone to tooth decay during and after radiotherapy. Your specialist team may prescribe artificial saliva product to help keep your mouth moist.

Following a regular mouth care routine is very important. It helps stop your teeth from rotting very quickly. Try to clean your teeth after every meal and at bedtime. You will need to see your dentist and oral hygienist regularly. Going for regular check-ups means that any mouth problems can be picked up early when they are easier to treat.

You will be shown how to keep your mouth and teeth clean, and given fluoride gel or toothpaste to apply to your teeth every day. It is important to use the gel, as it will help to protect and strengthen your teeth.

Radiotherapy can cause swelling in your gums. If you wear dentures, they may not fit as well during treatment. If your dentures are uncomfortable, try leaving them out overnight. You may need to stop wearing them until your treatment is finished.

You may be prescribed painkillers to take regularly. It is important to tell your cancer specialist if your mouth is still sore, as you may need stronger painkillers or have an infection in your mouth that needs treatment.


If you smoked before treatment, you will be encouraged to give up before it starts. This is because stopping will make sure treatment has the best effect. Stopping smoking can also help reduce side effects such as sore mouth or throat.

Eating and drinking

If your mouth or throat is sore, avoid drinking alcohol and eating spicy, sour, acidic or salty foods. You can be prescribed mouthwashes and protective gels that coat the lining of the mouth.

Choose soft foods and moisten them with sauces and gravies, butter or custard. This can make eating easier.

If you’re having problems with swallowing, ask to see a speech and language therapist. They can assess your swallowing and give helpful advice.

If you find eating difficult, you can talk to a dietitian. They might suggest you try high-calorie drinks such as Complan® and Build up®. They are available on prescription or you can buy them from a pharmacy or some larger supermarkets. You should discuss any eating problems with the dietitian or specialist nurse at the hospital. They may prescribe supplement drinks, such as Ensure® or Fortisip®, which are complete meals in liquid form.

Sometimes eating and drinking becomes too uncomfortable and some people need to be fed through a type of feeding tube. Different tubes include:

  • a feeding tube placed through the skin and muscle of the abdomen into the stomach (gastrostomy tube)
  • a thin tube passed down the nose into the stomach (nasogastric tube).

For patients at high risk, doctors sometimes recommend that the feeding tubes are inserted before treatment begins. Your doctor will talk to you about your situation.

Once your course of radiotherapy has finished, your mouth will gradually heal. Most people get back to eating normally after a few weeks or months.

Tips for caring for your mouth and teeth during radiotherapy

Here are some tips for looking after your mouth and teeth:

  • Brush your teeth and dentures with a small, soft toothbrush after each meal.
  • Use fluoride toothpaste and fluoride gel or mouthwash daily, as prescribed by your dentist.
  • Rinse your mouth with a non-alcohol based mouthwash. A salt water mouthwash can be used. To make the mouthwash, add one teaspoon of salt to a tumbler of water.
  • Inspect your mouth daily for signs of infection. You can ask your dentist or specialist nurse what to look for.
  • Take sips of water and rinse your mouth regularly during the day to keep your mouth moist.
  • Avoid sugary foods or sugar in drinks in between meals.
  • Avoid acidic drinks, such as fizzy drinks and fruit juices.
  • Sparkling water can help to break down thick mucus or saliva.
  • Do jaw exercises as advised by your specialist to prevent jaw stiffness.
  • Visit your dentist and hygienist every three to six months. Let them know you are having radiotherapy treatment.
  • Try to practice swallowing during treatment, even if your throat becomes sore. It will help to maintain the action even if it is just sips of water. This will help with your recovery once treatment finishes. Talk to your speech and language therapist about this.

If you have any concerns about your oral health during your treatment, make sure you raise them with your doctor, specialist nurse or radiographer.

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