CBCT uses ionising radiation. The examination should be justified, limited to the required area and adjusted to the patient.
Why radiation can feel frightening
It is reasonable to be concerned when an examination uses ionising radiation. Radiation can damage cells, and radiation-protection models assume that exposure may produce a small increase in lifetime cancer risk. At the relatively low doses used in dental imaging, the exact increase for an individual patient cannot be predicted with certainty.
The aim is not to say that the risk is zero. It is to use CBCT only when the expected diagnostic or treatment-planning benefit justifies the exposure and to limit the scan to the area that is actually required.
There is no single CBCT dose
Dose varies considerably between scanners and protocols. Important factors include the field of view, the part of the head being imaged, image resolution, exposure settings, patient size and whether repeat imaging is required. A small, focused tooth scan is different from a large volume including both jaws and facial structures.
CBCT generally uses more radiation than routine intraoral dental X-rays or an OPG, but often less than conventional medical CT of the same region. These comparisons are approximate because protocols differ.
How dose is reduced
- Use CBCT only when the result is expected to affect diagnosis or treatment.
- Select the smallest field of view that includes the required anatomy.
- Adjust exposure settings for patient size and the clinical question.
- Avoid unnecessarily high resolution when it will not change management.
- Review previous imaging to avoid duplication.
- Position the patient carefully to reduce motion and repeat scans.
- Use particular caution for children and adolescents, who are more sensitive to radiation.
Lifetime risk and online calculators
Estimated lifetime risk depends on age, sex, the organs exposed and the dose. Younger patients generally have a higher estimated lifetime risk because they are more radiosensitive and have a longer remaining lifespan.
Some patients use online radiation-risk calculators for preliminary perspective. Generic calculators may not include the exact CBCT protocol and may use dose assumptions that differ substantially from the dose delivered by a particular clinic. The result should therefore be treated as a broad estimate, not an individual prediction.
Pregnancy and children
Tell the clinic if you are pregnant or may be pregnant. Dental imaging may still be appropriate when clinically necessary, but timing, field of view and alternatives should be considered. In children, CBCT should be targeted to a specific question and performed with the smallest suitable field of view and exposure settings.
Frequently Asked Questions
Does the radiation stay in my body?
No. X-rays pass through the body during the scan and do not remain afterwards.
Is there a maximum number of CBCT scans I can have?
There is no simple annual number that applies to everyone. Each scan should have a clear indication and previous imaging should be reviewed before repeating it.
Why is a small field of view important?
It limits the exposed area and can improve detail for the specific target while reducing unnecessary radiation to other tissues.
Related Patient Guides
See the full MBR Health Patient Guides library for simple information about imaging, preparation, safety and results.
- PG5001 Cone Beam CT: What to Expect Before, During and After Your Scan
- PG5002 Cone Beam CT vs OPG and Standard Dental X-Rays
- PG5004 Cone Beam CT for Dental Implant Planning
- PG5005 Cone Beam CT for Wisdom Teeth and Oral Surgery
- PG5006 Cone Beam CT for Root Canal and Endodontic Assessment
- PG5007 Cone Beam CT for Orthodontics and Impacted Teeth
- PG5008 Cone Beam CT for the Jaw Joint and Facial Skeleton
- PG5009 Sinuses, Airways and Incidental Findings on Dental CBCT
- PG5010 What Cone Beam CT Can and Cannot Show
Related MBR Health services: X-ray & Dental Imaging • Dental X-Ray • Spectral CT
More FAQs: For other common imaging and appointment questions, visit the MBR Health FAQs page.
| Important: CBCT should not be a routine “just in case” scan. The expected benefit, field of view and patient-specific radiation considerations should be reviewed before exposure. |
PATIENT GUIDE • PG5003 | Patient information: low-dose cone beam CT Gold Coast
Looking for accurate, low-dose cone beam CT on the Gold Coast?
Patients searching for safe, accurate or advanced dental imaging on the Gold Coast should ask how the field of view and exposure are matched to the clinical question. The goal is not the lowest possible dose at any cost; it is the lowest reasonable dose that still provides diagnostic information. MBR Health combines targeted dental CBCT with specialist radiologist interpretation and access to other imaging when CBCT is not the best test.
Explore: X-ray & Dental Imaging • Spectral CT
