In: CBCT 3D Imaging
CBCT scans show your jaw in 3D, but they cost more and deliver more radiation than a standard X-ray. Here is when the upgrade is worth it.
What CBCT does that 2D cannot
A traditional X-ray is a 2D shadow - overlapping structures (roots, bone, sinuses) are flattened into one plane. CBCT captures hundreds of slices and reconstructs them into a 3D volume that can be viewed from any angle. Critical for cases where depth, width, or 3D position matter - bone volume for implants, root canal anatomy in complex teeth, airway dimensions, joint anatomy, and impacted tooth relationships.
When CBCT is essential
- Dental implant planning - must know bone width, height, density, and proximity to the inferior alveolar nerve and sinus floor.
- Complex endodontics - when 2D suggests missed canals, calcified canals, or vertical root fractures.
- Impacted wisdom teeth close to the nerve - CBCT dramatically reduces nerve injury risk.
- Surgical extractions of teeth with complex root anatomy or close to anatomic structures.
- TMJ imaging - bony anatomy of the joint.
- Sleep apnea airway evaluation in some cases.
- Suspected jaw cysts or pathology - extent and location.
- Orthodontic planning for some complex cases.
When CBCT is NOT needed
A 2D X-ray does the job for most routine work:
- Cavity diagnosis between teeth - bitewings are far better than CBCT for this.
- Routine periodontal bone-level monitoring - bitewings or vertical bitewings are sufficient.
- Simple extractions of fully visible teeth.
- **Standard crown and filling work.
- Routine recall exams - bitewings yearly are the standard.
We do not order CBCT routinely. The ALARA principle - "as low as reasonably achievable" - applies.
Radiation dose comparison
A small-field-of-view CBCT delivers about 0.05-0.1 mSv - equivalent to 1-2 weeks of background radiation, or one cross-country flight. A large-field CBCT (full skull) delivers 0.2-0.5 mSv. Compare to a traditional medical chest CT at 7 mSv. CBCT is therefore much lower-dose than medical CT but higher than dental bitewings (~0.005 mSv each). Acceptable when clinically indicated; not appropriate for routine screening.
How we use CBCT in our practice
At Stephen Cheung DDS:
- Standard 2D imaging for routine exam and cavity detection.
- CBCT recommended only when clinically necessary - implants, complex endodontics, surgical extractions near nerves, suspected pathology.
- Smallest possible field of view to limit radiation to only the area being studied.
- Lead shielding and protective protocols during scanning.
- Records reviewed before recommending - we don't reorder a recent CBCT from another office.
We explain what we are looking for, what the scan adds, and what it costs before ordering.
Frequently asked questions
- How long does a CBCT scan take?
- The scan itself takes 10-40 seconds. The whole appointment, including positioning, takes about 10 minutes.
- Will my insurance cover CBCT?
- Coverage varies. Some plans cover CBCT when there is a clear surgical or implant indication. We pre-verify and inform you of any out-of-pocket cost before the scan.
- Can I bring my own CBCT from another office?
- Yes, often. If the scan is recent and includes the area we need to evaluate, we can use it.
- Are CBCT scans safe for children?
- CBCT in children is reserved for specific clinical indications - impacted teeth, suspected pathology, complex orthodontic planning. We minimize field of view and dose for pediatric patients.