Patients smiling for a dental imaging guide

Published September 22, 2025Written by Landmark Dental Care

What Is a CBCT Scan in Dentistry?

A dental CBCT scan is a cone-beam computed tomography exam that uses a rotating, cone-shaped X-ray beam to create a three-dimensional image of teeth and nearby anatomy. A dentist may recommend it for selected diagnostic or planning questions. It is not a routine substitute for bitewing, periapical or other conventional dental radiographs.

Key Takeaways

  • CBCT reconstructs a 3D volume from X-ray data collected as the scanner rotates around the patient.
  • Dentists may consider CBCT when three-dimensional detail is expected to change diagnosis or planning and lower-exposure options are not enough.
  • CBCT typically involves more radiation than conventional dental X-rays, so clinical justification and ALARA principles still apply.
  • Ask what question the scan is meant to answer, and whether another image type could provide the needed information.

What cone-beam imaging shows that 2D images may not

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. Those data are reconstructed into a three-dimensional image of dental structures and related oral and maxillofacial anatomy.

A conventional dental radiograph is a two-dimensional projection. Useful as that is for many everyday questions, a flat image can overlap structures and limit depth assessment. CBCT provides volumetric information that can be viewed in multiple planes, which may help a clinician evaluate relationships that are difficult to judge on a single 2D view.

That added dimensionality does not automatically mean more information is always better. Extra detail is valuable only when it answers a defined clinical question. Soft-tissue contrast, image artifacts and the size of the scanned field also affect what a particular scan can and cannot clarify. Your dentist should explain what the 3D data are expected to show in your case.

CBCT is related to medical CT in concept, but dental CBCT systems are designed for dental and maxillofacial imaging tasks. Comparisons with hospital CT exams should be made carefully; dose, field and purpose vary. For patient education, the practical distinction is usually between selected 3D cone-beam imaging and the routine 2D radiographs used in many dental visits.

When a dentist may recommend CBCT

CBCT is generally considered when the expected benefit of three-dimensional information outweighs the radiation risk and when lower-exposure imaging will not provide what is needed. The ADA and FDA recommend that dental X-ray examinations, including CBCT, be performed only when necessary for diagnosis or treatment of disease.

A recommendation may follow an examination, review of symptoms and assessment of existing 2D images. Examples of the kinds of clinical questions that can lead dentists to consider three-dimensional imaging include situations where depth, spatial relationships or anatomy outside a single flat plane matter for planning or diagnosis. Exact indications vary by patient and by what information would change care.

This article does not assume that any one application applies to every practice or every patient. Availability of CBCT, the clinical problems a given office evaluates with it and the equipment used should be confirmed with the dental team. What matters for patients is the decision process: Is there a specific question? Will the answer affect care? Have simpler imaging options already been considered?

If CBCT is proposed, ask how the findings will be used. Imaging that does not change diagnosis, monitoring or treatment planning is harder to justify under radiation-protection principles.

To learn how 3D imaging is presented within Landmark Dental Care’s diagnostic services, see the practice page on 3D CBCT imaging.

How the scan differs from a routine X-ray

A routine dental X-ray appointment often uses small intraoral sensors or selected extraoral views to answer common questions about teeth and supporting bone. Capture is usually brief for each exposure, and the images remain two-dimensional.

A CBCT exam uses a dedicated cone-beam system. The patient is positioned according to the region of interest, and the machine rotates while collecting the dataset used to build the 3D volume. The appointment experience differs from holding a bitewing tab, but the core principle is the same: ionizing radiation is used only when justified.

The FDA notes that although radiation doses from dental CBCT exams are generally lower than many other CT exams, dental CBCT typically delivers more radiation than conventional dental X-ray exams. That relative difference is one reason CBCT is not treated as a default upgrade from everyday radiographs. It is reserved for selected needs.

Image review may include scrolling through slices or examining reconstructed views. Interpretation quality depends on scan parameters, the clinical question and the clinician’s training. Some cases may warrant specialist radiologic review; that decision belongs to the treating dentist.

Limitations and when CBCT is not the first choice

CBCT has clear limits. It is not automatically the best first image for every dental concern. Many cavities, periodontal assessments and routine monitoring questions are still addressed with conventional radiographs selected after examination.

Professional safety recommendations emphasize incorporating CBCT only when lower-exposure options will not provide the necessary diagnostic information. Using a larger field of view or more complex imaging than needed can increase exposure without improving the answer. Optimization includes matching the scan to the question rather than capturing the largest possible volume by default.

CBCT can be affected by artifacts from metal restorations or patient movement. It may not replace clinical examination, medical imaging ordered for non-dental disease, or biopsy when tissue diagnosis is required. A 3D scan also does not guarantee a specific treatment outcome.

Concerns about radiation exposure are greater for younger patients because they are more sensitive to ionizing radiation and have a longer lifetime ahead, according to FDA patient information on dental CBCT. Extra care with justification is therefore important for children and adolescents.

Pregnancy should be disclosed before any ionizing imaging. As with other dental radiographs, the need for imaging during pregnancy should be discussed openly so elective exposures can be deferred when appropriate and essential imaging kept to the minimum required.

What to discuss before a scan

Before agreeing to CBCT, make sure you understand the purpose, alternatives and practical steps. Helpful questions include:

  1. What clinical question will this scan answer? Ask for a plain-language explanation tied to your symptoms or treatment plan.
  2. Why is a 2D X-ray not enough? The answer should explain what three-dimensional information adds.
  3. What happens if we wait or use another image first? Understanding alternatives supports informed consent.
  4. How will findings be explained to me? Ask who will review the images and when you will hear the results.
  5. What should I tell you about pregnancy, recent imaging or childhood health? Share details that affect justification and timing.

Also ask about preparation, positioning and whether removable metal objects should be taken out for the scan. Follow the specific instructions given by the office performing the exam.

FAQ

Is a dental CBCT the same as a medical CT scan?

No. Both create cross-sectional or volumetric X-ray images, but dental CBCT systems are designed for dental and maxillofacial imaging tasks and differ from many hospital CT protocols in purpose and technique. Your dentist can explain why one modality is being considered for your question.

Does everyone need a CBCT before dental treatment?

No. CBCT is for selected situations where three-dimensional information is expected to help and conventional radiographs are not sufficient. Many dental decisions are made with examination and routine 2D imaging alone.

Does CBCT use more radiation than regular dental X-rays?

Dental CBCT exams typically involve more radiation than conventional dental X-rays, according to the FDA, even though doses are generally lower than many other CT exams. That is why justification and ALARA-based optimization matter before a scan is ordered.

Next step

If your dentist has discussed three-dimensional imaging or you want to understand when CBCT may be considered, learn about 3D CBCT imaging at Landmark Dental Care or call 902-893-2919 to ask about an assessment at 125 Queen St in Truro.

References

This article provides general educational information and is not a diagnosis or a substitute for care from a dentist or other qualified health professional.