CBCT and Radiation FAQs

People often have questions about CBCT scans. Below are some questions that we are frequently asked. If you have other questions, please ask one of our staff and they would be glad to explain things to you.

What is a CBCT?

CBCT stands for Cone Beam Computed Tomography. CBCT, also known as a CT or CAT scan, sends x-rays through the patient’s body to form a picture of the inside of the body.

What is an x-ray?

An x-ray is a beam of radiation, similar to light, that can penetrate through the body.

How is CBCT different than an x-ray film?

To make an x-ray film, an x-ray machine sends x-rays through a patient toward a film. Some of the x-rays are stopped by the patient’s bones and other tissues, creating a “shadow” on the film. With CBCT, an x-ray machine circles around the patient, sending x-rays as it goes around. Using a computer, pictures are created that look like many “slices” of the body. These pictures tell more about the inside of the body than x-ray film.

Does CBCT use radiation?

Yes. Because CBCT uses x-rays, a small amount of radiation is given to the patient.

How much radiation is used?

Very little. All of us receive small amounts of radiation all the time—mainly from the sun and the soil. Scientists call this background radiation. To put it into perspective, we can compare the amount of radiation used in dental CBCT and x-ray films to the amount of background radiation we receive every day.

SOURCE OF RADIATION

  • Dental x-ray
  • 3 hour airline flight
  • Dental CBCT scan
  • Chest x-ray
  • Head CT
  • Abdominal CT
  • Chest CT
  • Upper GI x-ray
  • Lower GI x-ray
  • Abdominal and Pelvis CT

DAYS OF BACKGROUND RADIATION

  • 1 day or less
  • 1 day
  • 1-4 days
  • 10 days
  • 4 months
  • 1.5 years
  • 2 years
  • 2 years
  • 3 years
  • 3 years

Adapted from: http://www.radiologyinfo.org/en/info.cfm?pg=safety-xray

Is this radiation harmful?

Even small amounts of radiation carry a low risk of being harmful. The effect of a small amount of radiation is not clearly understood, but doctors assume that it slightly increases the risk of cancer. On the other hand, CBCT provides very useful information that usually makes it worth the risk.

How much does a CBCT increase cancer risk?

According to the Canadian Cancer Society 1 out of 4 Canadians (29% of men and 24% of women) is expected to die from cancer. The risk of radiation-induced cancer from a dental CBCT scan is about 1 in a million. In other words, compared to the natural risk of cancer, the additional risk is negligible.

What About Children?

Concerns about radiation exposure are greater for younger patients (especially under 18) because they are more sensitive to radiation and they have a longer lifetime for ill effects to develop.

Benefits/Risks?

According to the FDA, when used appropriately, the benefits of a CBCT scan far exceed the risks. X-ray imaging, including dental CBCT, provides a fast, non-invasive way of answering a number of clinical questions. Dental CBCT images provide detailed, three-dimensional (3-D) information, rather than the two-dimensional (2-D) information provided by a conventional X-ray image.CBCT scans can provide detailed information to diagnose, plan treatment for, and evaluate many conditions in adults and children. Additionally, the detailed images provided by CBCT scans may eliminate the need for exploratory surgery. (This is according to the FDA which regulates the safety and effectiveness and radiation control of all X-ray imaging devices, including CT in the US.)

What’s the Bottom Line?

When used appropriately, the benefits of a CBCT scan far exceed the risks.