A dental CBCT scan is a three-dimensional X-ray that uses a rotating, cone-shaped beam to image teeth, jawbone, nerves and sinuses in a single pass. A dentist may recommend a CBCT scan when a flat X-ray cannot answer a specific planning or diagnostic question. It is not a routine replacement for checkup X-rays.
Key Takeaways
- A dental CBCT (cone-beam computed tomography) scan builds a 3D image of a selected area of the teeth and jaws that can be viewed from any angle.
- CBCT is most often used for selected questions such as dental implant planning, impacted teeth, complex root canal anatomy and locating nerves or sinuses before surgery.
- According to the FDA, dental CBCT typically delivers more radiation than conventional dental X-rays, but generally less than other CT exams.
- Health Canada's Safety Code 30 says CBCT should be prescribed only when lower-dose dental X-rays cannot meet the clinical goal, using the smallest field of view that will do the job.
- A CBCT scan clarifies anatomy; it does not guarantee a treatment result or replace a clinical exam.
What is a dental CBCT scan?
A dental CBCT scan, short for cone-beam computed tomography, is a type of CT imaging designed for the teeth, jaws and face. According to the U.S. Food and Drug Administration, dental CBCT systems rotate around the patient and capture data with a cone-shaped X-ray beam, and those data are reconstructed into a three-dimensional image of dental, oral and maxillofacial structures.
The "cone" in the name describes the beam. A 2012 position statement from the American Academy of Oral and Maxillofacial Radiology explains that CBCT uses a single X-ray source that produces a cone of radiation, rather than the fan-shaped beam of a hospital CT scanner, and that one rotation is enough to collect the data for the whole volume. The X-ray source and detector turn together around your head while you stay still.
The result is not a single picture but a stack of thin image slices. Your dentist can scroll through the volume, look at the jaw from the front, side or top, and measure distances between structures. The images can also be zoomed and adjusted for contrast, which helps with close review of a specific area.
That is the key difference from a regular dental X-ray. A bitewing or periapical X-ray is a two-dimensional projection, so everything in the beam's path overlaps on one flat image. CBCT separates those layers, which lets a dentist judge depth, width and the true position of one structure relative to another.
What does a CBCT scan show that 2D X-rays may not?
A CBCT scan shows the teeth, jawbone and nearby structures in their true three-dimensional relationships. Findings a dental CBCT scan can help evaluate include:
- the height, width and shape of the jawbone where a tooth is missing;
- the position of the nerve canal in the lower jaw and the floor of the sinus in the upper jaw;
- impacted teeth, including wisdom teeth, and their relationship to nerves and neighbouring roots;
- root shape and extra or curved canals that matter for root canal treatment;
- some root fractures and infection around root tips that a flat image may not show clearly;
- cysts, growths and other bone changes;
- the jaw joints (temporomandibular joints) and the size and shape of the airway.
Because the volume can be exported to planning software, some systems also let a dentist build a virtual model and plan a procedure, such as an implant position, before treatment begins.
Three-dimensional detail has limits. The AAOMR notes that soft-tissue contrast in CBCT images is inferior to that of medical CT, so CBCT is mainly a tool for teeth and bone, not for detailed soft-tissue diagnosis. Metal fillings, crowns and implants can create streaks called artifacts, and movement during the scan can blur the image. A CBCT scan can show the airway's shape, for example, but it does not diagnose sleep apnea on its own.
When might a dentist recommend a CBCT scan?
A dentist may recommend a CBCT scan when three-dimensional information is expected to change the diagnosis or plan and a lower-dose image is not enough. The ADA's 2024 radiography recommendations advise incorporating CBCT only when lower-exposure options will not provide the necessary diagnostic information. Health Canada's Safety Code 30 uses similar language for Canadian practices.
The decision usually follows an exam, a review of your symptoms and a look at existing 2D X-rays. This table shows common situations and what 3D imaging may add:
| Situation | What CBCT may add | When 2D imaging may be enough |
|---|---|---|
| Dental implant planning | Bone height and width, nerve and sinus position, implant angle | Early discussion of options, before a site-specific plan |
| Impacted or wisdom teeth | Relationship of roots to the nerve canal or sinus | Tooth is clearly away from key structures on a panoramic image |
| Complex root canal problems | Extra canals, curved roots, some fractures or hidden infection | Straightforward single-canal teeth |
| Bone grafting | Size and shape of the defect before and after grafting | Routine monitoring of healed sites |
| Jaw joint or unusual bone findings | Joint shape, cysts or growths in three planes | Symptoms explained by exam and routine images |
| Cavities and checkups | Rarely needed | Bitewing and periapical X-rays are the usual tools |
This list is not a menu for every patient. Exact indications depend on the individual case, and some complex cases may be referred to a specialist. For a step-by-step look at implant use, see how CBCT supports dental implant planning.
To learn how 3D imaging fits into Landmark Dental Care's diagnostic services, see the practice page on 3D CBCT imaging.
How does dental CBCT compare with medical CT and regular X-rays?
Dental CBCT sits between routine dental X-rays and hospital CT in radiation exposure, while offering fine detail of teeth and bone. The comparisons below are drawn from the FDA and the AAOMR position statement:
| Feature | Regular dental X-rays | Dental CBCT | Medical CT |
|---|---|---|---|
| Image | Two-dimensional | Three-dimensional volume | Three-dimensional slices |
| Beam | Small, focused beam | Single cone-shaped beam, one rotation | Fan-shaped beam with multiple detector rows |
| Radiation (per FDA) | Lowest of the three | Typically more than conventional dental X-rays | Dental CBCT doses are generally lower than other CT exams |
| Soft-tissue detail | Limited | Limited (AAOMR) | Better soft-tissue contrast |
| Typical setting | Dental office, most visits | Dental office, selected cases | Hospital or imaging centre |
The AAOMR adds an important caution: radiation doses vary widely among different CBCT systems and scan settings, including field of view and scan time. That is one reason this article does not give a single dose number. Your dentist's choice of settings matters more than a generic figure. Our comparison of CBCT and standard dental X-rays covers this in more depth.
Is dental CBCT radiation a concern?
Dental CBCT uses ionizing radiation, so each scan should be justified and kept as small as the question allows. According to the FDA, dental CBCT exams typically deliver more radiation than conventional dental X-rays, although doses are generally lower than other CT exams. The FDA states that dental CBCT should be performed only when necessary to provide clinical information that cannot be provided by other imaging.
Health Canada's Safety Code 30 sets out how Canadian offices should keep CBCT exposure down. It says the smallest available field of view that meets the clinical objective must be used. A small field covering a few teeth exposes less tissue than a scan of both jaws.
Children and teens
According to the FDA, radiation concerns are greater for younger patients because they are more sensitive to radiation and have a longer lifetime for effects to develop. Safety Code 30 requires child-specific settings for pediatric imaging. The FDA suggests parents ask whether the facility uses size-based protocols for children and whether an equally useful exam with less or no radiation exists.
Pregnancy
Tell the dental team if you are pregnant or might be before any X-ray, including CBCT. Elective scans, such as planning for a future implant, can usually wait until after pregnancy. Essential imaging for an urgent problem is a separate discussion with your dentist.
Shielding
Canadian and American guidance currently differ on shielding. Safety Code 30 says patients should be given a lead apron for CBCT procedures when it will not interfere with the image. The ADA's 2024 recommendations advise discontinuing lead aprons and thyroid collars because they can block the beam and cause retakes. Your dental team follows Nova Scotia's requirements and can explain what they use.
What a CBCT scan does not do
A CBCT scan does not replace your regular checkup X-rays. Cavities between teeth and routine gum monitoring are still usually checked with bitewing and periapical images. The AAOMR advises against using CBCT for periodic review of implants that have no symptoms, and its guidance recommends panoramic and intraoral X-rays, not CBCT, as the starting point for implant assessment.
CBCT also does not replace a clinical exam, a biopsy when tissue diagnosis is needed, or medical imaging ordered by a physician for non-dental problems. It does not guarantee that an implant, extraction or root canal will go a certain way. What it does is reduce uncertainty about anatomy so your dentist can plan with better information.
Finally, a larger scan is not automatically a better one. Imaging more area than needed adds exposure and can turn up incidental findings unrelated to the original question. The AAOMR recommends that every CBCT volume be reviewed for signs of abnormality, so ask how any unexpected findings would be handled.
Questions to ask before a scan, including cost and coverage
Before agreeing to a CBCT scan, make sure you understand its purpose and the alternatives. Helpful questions include:
- What question will this scan answer? Ask for a plain-language explanation tied to your symptoms or treatment plan.
- Why is a 2D X-ray not enough? The answer should explain what the 3D view adds.
- How large an area will be scanned? A smaller field of view means less exposure.
- Can recent scans from another office be used? A usable scan may avoid a repeat.
- Who reviews the images, and when will I hear the results? Some cases include specialist review.
- What should I tell you first? Mention pregnancy, recent head or neck imaging, and any trouble staying still.
Cost depends on several factors, including the size of the area scanned, whether the scan is part of a larger treatment plan and whether a specialist report is needed. Dental insurance plans differ in whether and how they cover CBCT, and some ask for a written reason before paying. Ask the office for an estimate and check your plan before the appointment. If you are asking about the federal program, see our Canadian Dental Care Plan page and call to confirm current participation and billing.
Getting a CBCT scan in Truro
Landmark Dental Care is a family general practice at 125 Queen St in downtown Truro, with a special interest in restorative dentistry. The practice offers 3D CBCT imaging alongside digital dental X-rays, which means a patient from Truro, Bible Hill or elsewhere in Colchester County who needs 3D imaging for planning may not need a separate trip to another centre. Whether a scan is appropriate is decided after an exam.
If you have a CBCT scan from another clinic or a specialist, bring the file or ask for a transfer before your visit. Knowing what the scan covered and when it was taken helps the team decide whether a new one is needed. For what happens on the day, read what to expect during a dental CBCT scan.
FAQ
Is a dental CBCT the same as a CT scan?
Not exactly. Both are X-ray methods that produce 3D images, but dental CBCT uses a cone-shaped beam and one rotation, is designed for the teeth and jaws, and, according to the FDA, generally involves lower doses than other CT exams. Medical CT shows soft tissue better and is used for different questions.
Does everyone need a CBCT scan before dental treatment?
No. CBCT is for selected cases where 3D information is expected to change the plan. Most fillings, cleanings and checkups rely on an exam and regular 2D X-rays.
Does CBCT use more radiation than regular dental X-rays?
Yes, typically. The FDA says dental CBCT usually delivers more radiation than conventional dental X-rays, though generally less than other CT exams, and the exact dose depends on the machine and settings.
How long does a dental CBCT scan take?
The rotation itself is short, but total time includes positioning and checking that the image is usable. Ask the office how long to plan for, since it depends on the equipment and area scanned.
Can a CBCT scan find cavities?
It can show some decay, but it is not the usual tool for finding cavities. Bitewing X-rays remain the standard for checking between teeth, and metal fillings can cause streaks that make decay harder to judge on CBCT.
Next step
If your dentist has mentioned a 3D scan or you want to understand whether one could help with an implant, wisdom tooth or root canal question, learn about 3D CBCT imaging at Landmark Dental Care. Call 902-893-2919 or contact the office to book an assessment at 125 Queen St, Truro, Monday to Friday, 8:30am to 5:00pm.
References
- U.S. FDA: Dental Cone-beam Computed Tomography
- Health Canada: Radiation Protection in Dentistry — Safety Code 30
- Canadian Dental Association: Control of X-Radiation in Dentistry
- American Dental Association: X-Rays/Radiographs
- American Dental Association: Updated recommendations to enhance radiography safety in dentistry (2024)
- Tyndall DA et al. Position statement of the AAOMR on selection criteria for the use of radiology in dental implantology with emphasis on CBCT. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012 (PDF)
This article provides general educational information and is not a diagnosis or a substitute for care from a dentist or other qualified health professional.
About this guide
This article was written and reviewed by the Landmark Dental Care Team at Landmark Dental Care, 125 Queen St, Truro, NS B2N 2B4. It is general patient education and is not a diagnosis or a substitute for an examination. If you have pain, swelling or a change in your mouth, call us at 902-893-2919 so a dentist can assess you.