Cone Beam Computed Tomography (CBCT)

Cone Beam Computed Tomography (CBCT)

It is not possible to see all the details using conventional X-ray technology. The use of a CBCT scan allows the dentist to observe the spatial distribution of roots, the details of a root-canal system as well as the surrounding maxillo-facial structures.

Tumors and inflammatory changes in the jawbone are often overlooked due to the high density of bones and they can be masked by anatomical structures like the cheek bone (See Lofthag-Hansen, S., S. Huumonen, et al. (2007). „Limited cone-beam CT and intraoral radiography for the diagnosis of periapical pathology.“ Oral Surg Oral Med Oral Pathol Oral Radiol Endod 103(1): 114-9).

The CBCT technique allows the high resolution representation of teeth and jaw structures in thin slices in all three dimensions, increasing diagnostic reliability. The voxels (3D pixels) are extremely small (about 49 µm) as is the scanned volume (4×4 cm). Periapical radiography.

A CBCT scan is appropriate in the following circumstances:

1. Suspicion of an inflammatory disease in the jawbone arising from infected root-canal systems which cannot be detected on a conventional periapical x-ray.
2. Prerequisite for correct endodontic diagnosis and treatment planning (e.g., to confirm unidentified canal systems, complex root anatomy, perforations or root fractures).
3. When planning microsurgery on roots in the immediate vicinity of anatomical structures like the maxillary sinus, the mental or the mandibular nerve.
4. Diagnosis after dental trauma (to determine fractures of the root or jaw bone )
5. Diagnosis and treatment planning in cases of internal and external root resorption.

Effective doses from different sources of dental radiation

Conventional CT scans for imaging the maxilla and mandible cause a radiation dose of about 2.00 millisieverts (mSv), which corresponds to about 345 panoramic tomograms. In contrast, a digital volume tomogram with a small scan volume results in an effective radiation dose of 0.005 to 0.038 mSv due to the limited “field of view” as well as the low tube voltage (60 KV) and low tube current (1.0 mA).