What is CBCT and how is it different than regular X-rays?
While suitable for identifying cavities, conventional dental X-rays can only produce two-dimensional images, which limits their usefulness in diagnosing more advanced conditions. Where conventional X-ray images use parallel beams of light, diagnostic technology such CBCT, which is available at our practice in San Antonio, TX, uses X-rays that extend in the shape of a cone.
As with large-scale medical CT imagers, the CBCT scanner rotates around you to form three-dimensional views. Dental scanners are much smaller, since they need only rotate around your head. Images produced by the CBCT provide detailed views of dental structures, bones, soft tissue, blood vessels, and nerve paths.
How are CBCTs used in a dental practice?
While radiation exposure levels from a CBCT are far lower than with conventional CT scanners, these are still higher than standard two-dimensional dental images, so the familiar bitewing X-rays may still be used when high-resolution, three-dimensional models aren’t necessary.
There are, however, treatments and procedures that become easier and more effective with the extra information provided by CBCTs. For example, planning extraction surgery for impacted teeth becomes easier, since the tooth, bone, and soft tissue are each portrayed in a CBCT image in three dimensions.
CBCT imaging also replaces conventional dental impression molds for use with teeth restoration, denture making, and orthodontic procedures. Some patients find the physical impression process uncomfortable, and the trays and casting material themselves interfere with the representation of your natural bite.
What should I expect during a CBCT session?
The procedure is not much different from a conventional X-ray, though you won’t need to clamp down on the bitewing films. The CBCT arm that rotates around your head has an X-ray source on one side and a detector on the other. The image-making cycle lasts about 20-40 seconds for a complete scan, and less when scanning only a particular part of your face.
As with other X-rays, you’re asked to remain as still as possible during exposure. You’ll feel nothing and there’s no recovery time needed. Through computer processing of the CBCT X-ray image, many views and angles can be retrieved from a single scan. Teeth, bones, and soft tissue are all imaged at the same time.