Three-Dimensional Basics: CT vs. CBCT

While speaking with my colleagues—and even patients—about 3D imaging, I am sometimes questioned about the difference between computed tomography (CT) and cone-beam computed tomography (CBCT).  Since we are in the beginning stages of our series on 3D, I thought this would be a great time to compare the two technologies and discuss the benefits of incorporating CBCT into your practice.

Differences between CT and CBCT

Invented in 1972 by Godfrey Hounsfield (of EMI Laboratories) and Allan Cormack (of Tufts University), conventional tomography gets its name from the Greek word “tomos”—slice or section—and graphia, which means “describing.” The first clinical CT scanners were installed in hospitals and clinics starting in 1974, though the early models were used only for scanning the head. Whole body systems became available in 1976. CBCT technology, in turn, got its start in 1993 after GE developed the first CT based on light-intensifier technology.

With that being said, the main difference between CT and CBT is the shape of the beams—CT scans use fan-shaped x-ray beams that rotate while the patient advances (think of a CAT scan) to capture limited thickness slices, while CBCT uses a cone-shaped area detector that does not require patient movement.

As far as dentistry goes, CBCT delivers a number of advantages over CT:

As to the last point—the fact that CBCT units are small enough to fit into practices provides a number of direct benefits to dental professionals:

• There is no need to send patients out to a third-party for imaging

• Exams can be performed according to patient needs

• A better workflow for the staff and patient

• Additional revenue can be generated by performing scans in house