Compared with cone-beam CT, standard CT generally has higher radiation exposure.

• A. Standard CT uses less radiation than CBCT.
• B. Compared with cone-beam CT, standard CT generally has higher radiation exposure.
• C. Standard CT is a handheld device.
• D. Standard CT cannot be used for dental implant planning.

Answer: (B)

Understanding how imaging dose differs between modalities helps explain why standard CT typically carries more radiation than cone-beam CT for dental purposes. Cone-beam CT uses a cone-shaped X-ray beam and a flat-panel detector that rotate around the patient to capture a 3D volume in a single or few passes. This setup often achieves the necessary detail for dental structures with a lower overall radiation dose, especially when the field of view is limited to the teeth and jaws. Standard CT, on the other hand, uses a fan beam (often with helical scanning) and thinner slices that cover a larger volume with higher tube current and longer exposure to reach high-resolution images. That combination generally results in more radiation delivered to the patient.

So the statement that standard CT generally has higher radiation exposure compared with cone-beam CT aligns with how these systems are designed and used in dental imaging. The other notions—that standard CT uses less radiation, that standard CT is a handheld device, or that it cannot be used for dental implant planning—do not fit the typical clinical realities of these modalities.