Radiation exposure can potentially lead to tooth decay and other oral health issues. However, the amount and type of radiation exposure matters significantly. Low levels of radiation, like from dental x-rays, CT scans, or background environmental radiation have not been shown to directly cause tooth decay. However, high doses of radiation, like those from radiation cancer treatments, can increase the risk of dental problems.
What is radiation?
Radiation is energy that is emitted from a source and travels through space in waves or particles. There are different types of radiation, including:
- Ionizing radiation – high frequency radiation like x-rays, gamma rays, and cosmic rays that can remove electrons from atoms and damage cell DNA. This type is higher energy and can be harmful in large doses.
- Non-ionizing radiation – lower frequency radiation like radio waves, microwaves, and visible light. This type generally does not have enough energy to ionize atoms and is less harmful.
We are exposed to small amounts of natural background radiation every day from cosmic rays from the sun and elements like uranium in the earth. We also encounter man-made sources regularly through medical imaging tests, air travel, electronics, and nuclear sites.
How does radiation exposure affect oral health?
High doses of radiation, especially ionizing radiation, can damage the soft tissues and bone that support the teeth. Side effects may include:
- Reduced saliva flow – Radiation can damage salivary glands, resulting in a permanently dry mouth (xerostomia). Saliva helps neutralize cavity-causing acids.
- Mucositis – Radiation can damage mucous membranes in the mouth, causing painful inflammation and ulcerations.
- Osteoradionecrosis – Radiation can weaken jaw bones, increasing risk of bone death (osteonecrosis) after trauma from dental work.
- Tooth enamel erosion – High radiation doses may subtly damage or alter the mineral structure of enamel, making teeth more prone to cavities.
- Reduced immune function – Radiation can lower white blood cells and antibodies needed to fight infections.
These issues make the mouth more vulnerable to tooth decay, periodontal disease, and infection after dental procedures. Poor healing can also cause problems with dentures, implants, and other restorations.
What radiation treatments increase dental risks?
The highest risk comes from radiation therapy to treat head and neck cancers, since the mouth is directly irradiated. Tissues may start to show damage within a few weeks.
Other cancer radiation treatments, like pelvic or chest radiation, can also increase dental risks since radiation can affect the whole body. However, the risks are lower than head and neck radiation.
Total body irradiation before bone marrow transplants is another high risk scenario. The goal is to suppress the immune system through irradiation before introducing the donor cells.
Does dental x-ray radiation cause cavities?
Dental x-rays use very low doses of radiation focused on small areas. A full mouth series of x-rays is only about 150 microsieverts (.15 mSv). Average background radiation exposure is 2,400 microsieverts (2.4 mSv) per year. There is no evidence this minor exposure causes tooth decay.
Can CT scan radiation damage teeth?
CT scans use x-rays and have higher radiation doses than dental x-rays because they create 3D images of large areas. A CT scan of the head can be around 2,000 microsieverts (2 mSv).
While CT scans do not directly impact the teeth, the higher radiation dose may slightly increase the overall risk of oral cancer. This risk is still low, but repeated CT scans without necessity should be avoided.
What about environmental radiation sources?
Background radiation from outer space, the ground, and everyday items is low. No studies have specifically linked background radiation to increased tooth decay.
Much higher radiation levels are required to see measurable dental effects. For example, nuclear plant workers exposed to estimated doses over 1,000 mSv had a higher incidence of gum disease, but no increase in caries. Doses this high are rare outside of accidents.
Can mobile phones or wifi signals damage teeth?
Cell phones, wifi, and other wireless devices emit non-ionizing radiofrequency radiation from their signals. The energy level is very low and focused on the skin surface. There is no credible evidence that the minimal heating effects can damage tooth enamel or oral tissues.
Does UV light exposure affect dental health?
UV light is also non-ionizing radiation. While excessive UV exposure from the sun or tanning beds can increase skin cancer risk, it does not penetrate deeply enough to impact tooth structure beneath the enamel. No studies have found links between UV light exposure and tooth decay.
How can radiation therapy patients minimize dental risks?
Here are some tips for patients before, during, and after radiation treatment near the mouth:
- Get a full dental exam and address any infections, decay, or gum disease before starting radiation.
- Discuss options like fluoride application or saliva substitutes to protect teeth during treatment.
- Use an extra soft toothbrush and fluoride toothpaste after radiation to avoid tissue trauma.
- Rinse mouth frequently during treatment to remove bacteria and prevent infection in damaged tissues.
- Avoid alcohol and tobacco, which further irritate irradiated oral tissues.
- Get regular dental checkups after treatment to detect and treat any new decay early.
- Avoid elective dental work on irradiated jaw bones due to osteoradionecrosis risk.
Key points
- High radiation doses from treatment for head, neck, or other cancers can increase risks of tooth decay, gum disease, and other oral health issues.
- The highest risk is from high energy ionizing radiation damaging the soft and hard tissues supporting the teeth.
- Lower energy radiation sources like dental x-rays, CT scans, and background radiation have not been shown to directly cause tooth decay.
- Patients receiving radiation therapy near the mouth need special precautions to minimize dental risks.
Conclusion
While excessive radiation exposure can negatively impact oral health, routine low-dose exposures from dental x-rays, medical scans, or the environment do not appear to be a direct cause of tooth decay. More research is still needed, but current studies have found no link between these kinds of radiation and increased rates of dental caries.
However, high therapeutic doses of radiation for head, neck, and some other cancers can damage tissues in the mouth and increase susceptibility to dental problems. Patients receiving this treatment require special dental care before, during, and after radiation to preserve oral health.