Which unit is used to measure patient radiation dose in dental radiography?

Which unit is used to measure patient radiation dose in dental radiography?

• A. Gray (Gy)
• B. Millisievert (mSv)
• C. Sievert (Sv)
• D. Roentgen (R)

Answer: (B)

In dental radiography, we describe the patient’s risk-related radiation dose using dose equivalent, which ties the energy deposited in tissue to potential biological effect. The millisievert is used because it expresses the dose in a unit that reflects stochastic risk for small, real-world dental doses. The sievert is the standard SI unit for dose equivalent, but dental exposures are very small, so reporting in millisieverts makes the numbers practical and meaningful. Absorbed dose, measured in gray, counts how much energy is deposited per mass but doesn’t account for how different tissues respond to radiation. Exposure in air, measured in roentgens, describes how much radiation exists in the air, not how much actually affects the patient’s tissues. So, for communicating and comparing typical dental procedures—bitewings, panoramics, or CBCT—the millisievert best represents the patient dose in terms of risk. For context, bitewings are usually a fraction of a millisievert, panoramic doses are a bit higher, and CBCT can be higher still depending on the field of view.

In dental radiography, we describe the patient’s risk-related radiation dose using dose equivalent, which ties the energy deposited in tissue to potential biological effect. The millisievert is used because it expresses the dose in a unit that reflects stochastic risk for small, real-world dental doses. The sievert is the standard SI unit for dose equivalent, but dental exposures are very small, so reporting in millisieverts makes the numbers practical and meaningful. Absorbed dose, measured in gray, counts how much energy is deposited per mass but doesn’t account for how different tissues respond to radiation. Exposure in air, measured in roentgens, describes how much radiation exists in the air, not how much actually affects the patient’s tissues. So, for communicating and comparing typical dental procedures—bitewings, panoramics, or CBCT—the millisievert best represents the patient dose in terms of risk. For context, bitewings are usually a fraction of a millisievert, panoramic doses are a bit higher, and CBCT can be higher still depending on the field of view.