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Utskriftsdato (25.2.2021)

Oral Hygiene Associated with Radiation Therapy

Medical editor Bente Brokstad Herlofsen MD
Oral Surgeon
Oslo University Hospital


Radiation treatment to the head/neck region causes bothersome side effects to the mouth. Proper care and hygiene of the mouth are therefore very important for the patient to be able to complete radiation treatment without unnecessary side effects.


  • Radiation therapy toward the head/neck region.


  • Prevent side effects from treatment
  • Relieve side effects from treatment
  • Maintain healthy status of teeth and oral mucosa 
  • Promote well-being


Radiation treatment to the head/neck region is detrimental to the mucous membranes of the mouth, teeth, jawbone, salivary glands, temporomandibular joint, masticatory muscles depending on radiation dose and location, and may cause acute and chronic side effects.

Mucositis is one of the most common acute side effects from radiation to the head/neck. It is defined as an inflammation-like process in the oral mucous membrane caused by ionizing radiation. Ninety to 100% of patients treated with radiation to this region develop mucositis. The extent varies with radiation field and dose. Mucositis increases the risk of serious infections including sepsis.  

Other acute side effects:

  • Infection
  • Salivary gland dysfunction
  • Dry mouth due to reduced saliva secretion
  • Taste dysfunction
  • Bleeding
  • Pain
  • Viscous mucous 

Pain in the mouth can reduce the patient's quality of life by reducing food intake, causing dysphagia, and hoarseness. The acute side effects last for up to 4-6 weeks after end of radiation therapy. 

Chronic side effects:

  • Salivary gland dysfunction
  • Dry mouth
  • Taste dysfunction
  • Cavities in the teeth
  • Periodontal disease
  • Osteo(radio)necrosis
  • Reduced mouth opening (trismus)

Optimal dental and oral hygiene without damage to the teeth, jaw, mucous membranes, and salivary glands, prevents and reduces severity of side effects and complications.


Patients to be treated with radiation toward the head/neck region should have the following assessed and/or treated before treatment starts.

  • Cavities in the teeth (number/severity)
  • Teeth which require endodontal therapy 
  • Periodontal disease
  • Periapical infection and other pathology in the jaw
  • Disease status related to wisdom teeth (pericoronitis)
  • Number of teeth which should be extracted 
  • Oral hygiene (instruction and follow-up)
  • Salivary gland dysfunction (information/measures)
  • Mucous membrane symptoms
  • Edges of teeth or fillings that may cause trauma to the mucosa
  • Temporomandibular dysfunction, measure of mouth opening

At least two week interval is necessary between tooth extraction and start of radiation treatment.


Measures to reduce side effects in the mouth from radiation therapy

Fluoride is effective for fighting cavities and can be ingested by chewable tablets, gum, or mouthwash. For patients suffering from dry mouth, a mouthwash is the most gentle mode. Fluoride should be taken in the morning and evening.  

If the patient has a sore and dry mouth, a toothpaste with a mild soap or a sodium lauryl sulphate-free toothpaste should be used. Dental floss and/or an interdental brush should be used daily.

The mouth should be rinsed with lukewarm 9% NaCl  after each meal, preferably more frequently. Mouthwash such as Corsodyl® should only be used for short periods to optimize the oral hygiene, diluted 50% with water. If toothbrushing and rinsing is to painful, the teeth may be cleaned with Q-tips soaked in Corsodyl®.

Due to the high risk of cavities in the teeth, sugar intake should be reduced.

For dry mouth, it helps to drink copious amounts of fluids. If necessary, artificial saliva and moisturizing gels can be used. It may also help to chew gum to stimulate saliva secretion. Sugar-free chewing gum is recommended. 

Oral hygiene for patients with sore mucous membranes

  • Use lip balm/cream. 
  • The patient is offered a pain medication 30 minutes before oral cleaning. The mucosa can also be numbed with viscous Xylocain® or Andolex® mouthwash.

If the oral cleaning will take place in the patient's bed, the patient should lie with their head to the side to avoid fluid draining down their throat.

  • Hold the pus basin under the mouth through the entire cleaning. 
  • For ulcers and crusts in the mouth, wash the patient's mouth with a swab dipped in 3% hydrogen peroxide (1 tbs to 1/2 glass water). This will loosen crusts and remove mucous.
  • Start by washing the tip of the tongue and work further dorsally on the upper and lower surface of the tongue and finish with the inside of the cheeks. Brush the teeth with a soft toothbrush and use a mild toothpaste.

In cases of suspicion of an infection, examine for bacteria, fungi, or a virus.

  • Use tooth floss or an interdental brush between the teeth.
  • Frequent change of toothbrush.
  • After cleaning the mouth, lubricate the patient's mucosa.
  • Finally, the lips should be lubricated with lip balm/cream.

Oral cleaning should take place at least 2 times per day.

Oral hygiene for patients with dentures

Before cleaning the mouth, the dentures are removed to clean with a toothbrush or nailbrush. Dish soap or toothpaste can be used. For tartar, dentures can soak in 7% vinegar overnight. Coregas® dissolvable tablets can be used to prevent tartar.

When the mouth is dry, dentures may loosen. It may be necessary to use an adhesive. The adhesive should be removed daily before a new layer is applied.  

The mucosa will be thinner as a result of radiation treatment. Dentures or sharp edges may therefore more easily give rise to blisters. Some patients may find it difficult to wear dentures.

Blisters from dentures increase the risk for developing osteoradionecrosis. In these cases, the patient should not wear dentures.

If the denture does not fit properly, adjustments should be postponed until the condition of the mouth has normalized. This usually takes 4-6 weeks after the last radiation treatment.  



  • Formation of ulcers and possible sign of infection in the mouth
  • Pain
  • Mouth opening should be measured regularly after radiation treatment if temporomandibular joint and jaw muscles were included in the radiation field. Jaw exercises should be implemented to keep adequate mouth opening.