Patient Dose in Dental Radiology
(for dental professionals)

Exposure of the patient during most diagnostic radiological procedures performed in the field of dental radiology is very small and there is a very small risk of adverse effects of ionizing radiation.

Patient exposure can be described by the effective dose expressed in sieverts. Sievert is a large unit of measurement, so the patient’s exposure in radiological diagnostic procedures is most often expressed in mSv (millisieverts, thousandths of a sievert) or even in µSv (microsieverts, one-millionth of a sievert).

The effective dose is related to the risk of exposing the whole body to ionizing radiation and is not intended to describe the radiation of an individual patient, but a typical patient. The effective dose of the patient can be used for the purpose of comparing different modalities, i.e. exposure of the patient when using different types of sources of ionizing radiation used in the implementation of a diagnostic radiological procedure.

The following table compares the effective doses of a typical patient for different diagnostic radiological procedures performed within dental radiology. The same table also shows exposure  of the population as a result of daily exposure to natural radiation and during overseas airplane flights. 

Type of image

Effective dose (µSv)

Single image of teeth

0.3 – 8

Panoramic image of the jaw (“orthopan”)

4 – 30

Cephalometric image (craniogram)

2-3

CBCT

180 – 1250

Overseas airplane flight

80

Exposure in one year as a consequence of exposure to natural radiation

2400

Even though the patient’s exposure is low in most of the listed diagnostic radiological procedures, it is extremely important to respect the principle of justification. Furthermore, the diagnostic radiological procedures themselves must be optimized, i.e. they must be performed in a way that ensures the least possible irradiation of the patient while maintaining the appropriate image quality. The required image quality must correspond to the clinicalquestion. Optimization includes, among other things, selecting the appropriate modality, imaging parameters, field size used (which is especially important in the case of CBCT), establishing and revising local diagnostic reference levels, and regularly performing quality control of X-ray devices and imaging systems, for which a medical physics expert should be consulted.