Radiotherapy is an essential and integral part of treating oral cancers. Although it is beneficial in reducing the size of the tumor, it comes with unwanted side-effects. During radiotherapy sessions, along with the tumor site, the surrounding structures like the salivary gland, jaw bone, and other dental tissues get exposed to the radiations. This incidence increases the probability of developing radiation caries, dry mouth, and inflamed oral tissues. In this article, we will be focusing our knowledge to one of the most common side effects of radiotherapy, which is radiation caries.
Radiation caries develop after several weeks of completing radiation therapy. This condition is prevalent among patients who undergo radiotherapy of head and neck. This condition initiates as a lesion around the neck of the teeth near the gums called the cervical area. With time, caries progresses and leads to loss of crown structure. Mild forms of radiation caries may include enamel erosion and tooth discoloration. This type of tooth decay is rampant, but with the right treatment and preventive measures, radiation caries can be controlled on time. Let’s continue to read further about radiation caries, its causes, treatment, and preventive measures.
What is radiation caries?
Radiotherapy is a non-invasive technique used to treat oral cancers. While it may prove to be helpful in this case, one of its significant side effects is exposure of salivary glands to radiation, which may cause radiation-induced xerostomia. Radiation caries is a type of tooth decay that is typically caused as a result of radiation-induced dry mouth. The probability of developing radiation caries is always high among post-radiation patients. (1)
What causes radiation caries?
As mentioned above, the prime cause of radiation caries is radiation-induced dry mouth. Radiation damages the functioning of the major salivary glands. Saliva plays a crucial role in moistening the oral tissues.
Its antimicrobial activity helps to control the growth of tooth decaying bacteria. Moreover, saliva provides minerals to the enamel for remineralization. (2)
Lack of salivary flow in the mouth fails to regulate bacterial growth. As a result, plaque and bacterial accumulation increase on the surface of the teeth.
What are the clinical signs of radiation caries?
Usually, symptoms of radiation caries become evident only in the later advanced stages. Enamel is the outer most layer of the teeth. It is made up of minerals and has no nerve innervations. Initiation of caries on the surface of enamel often goes unnoticed.
Once the decay progresses into the dentin and pulp, the symptoms of tooth sensitivity, pain, and discomfort may be experienced by the patient. (3) Radiation caries is rampant and affects more than one tooth at the same time. Clinically, it is seen as a discolored decay area around the cervical region of the tooth.
In advanced stages, radiation caries leads to loss of crown structure.
What is its treatment?
Treatment depends on the severity and extent of caries progression. The dentist will perform a thorough clinical examination along with dental x-rays to check the extent of caries. (4) Accordingly, the dentist may plan the following treatment –
- Surface caries involving only enamel or enamel and dentin can be treated with restorations such as composite fillings and crowns. Crowns are preferred to cover a large area of decay.
- Tooth decay associated with abscess usually goes for extractions.
- The advanced stages of radiation caries, which includes only root stumps, are also extracted and replaced by a dental bridge or implant.
How can radiation caries be prevented?
The risk of developing radiation caries increases with the increase in the dose of radiation therapy. It is, therefore, essential to take necessary precautions to take care of your dental health and prevent tooth decay.
Following are some of the preventive steps that you can follow to maintain good dental health throughout your radiation therapy –
- Follow a regular oral hygiene practice, which includes brushing twice a day with fluoridated toothpaste and a soft-bristled toothbrush. Floss at least once in a day.
- Use an antibacterial non-alcoholic mouthwash to hydrate the oral tissues.
- Modify your diet to moist food, which is easy to swallow and chew.
- Keep yourself hydrated by drinking lots of water during the day.
- Avoid smoking and drinking alcoholic beverages,
- Sugar-free chewing gums and artificial salivary substitutes stimulate salivary flow in the mouth and prevent tooth decay.
- Professional cleaning to remove plaque and calculus will take you a long way to maintain excellent dental health, especially if you are undergoing radiation therapy.
Routine dental visits at this point are crucial to detect any signs of radiation caries at an early stage and prevent it by appropriate treatments.
Take away message
Oral cancer is a life-threatening condition that requires all the attention and treatment to cure it completely. One of the first steps in curing oral cancer is radiotherapy. Radiotherapy is useful in reducing the size of the tumor, and often, it also eliminates the necessity of a surgical approach.
However, radiation therapy can expose other structures of the mouth like salivary glands, teeth, jaw bone, and oral mucosa. One of the side effects of radiotherapy is disruption of salivary gland functions. As a result, it causes radiation-induced dry mouth. Saliva is one of the critical components that regulate bacterial growth in the mouth and provides essential minerals to the enamel for remineralization.
Lack of saliva increases the susceptibility of tooth decay due to increased plaque and bacterial accumulation on the surface of the tooth. This condition is recognized as radiation caries. Radiation caries is a dominant form of tooth decay that starts as a lesion around the cervical area of the tooth and quickly progresses to a stage where the crown structure becomes weak and falls off.
Treatment of radiation caries depends on the extent and severity of the condition. However, taking care of your dental health right from the beginning eliminates the chances of formation of radiation caries.