Dental Radiography and Radiation Safety

Practice vocabulary flashcards covering dental radiography equipment, film speeds, radiation biology theories, units of measurement, and safety protocols based on the provided quiz notes.

Rectangular collimator

A device that restricts the x-ray beam 3 times more than a circular collimator and decreases patient exposure considerably.

Collimator

A component that restricts the size and shape of the x-ray beam.

F-speed film

Currently the fastest intraoral film available; it reduces absorbed dose by $60\%$ compared to D-speed film.

Stochastic biologic effects

Radiation effects that occur as a result of exposure, where the severity is not determined by dose and there is no dose threshold.

Cell sensitivity factors

Characteristics that make cells more sensitive to radiation, specifically if they are rapidly dividing or young.

Latent period injuries

Cellular injuries following the latent period which may include cell death, cessation of mitotic activity, or abnormal mitotic activity.

Injury stage

The stage of the radiation injury sequence where a patient may experience symptoms such as a burning sore throat and great difficulty swallowing.

rad (radiation absorbed dose)

The traditional unit of radiation dose.

MPD

Maximum Permissible Dose; the maximum dose equivalent that a body is permitted to receive within a specific period.

Average US background radiation

The average dose of background radiation received by an individual in the United States each year, which is $6.2\,mSv$.

Cosmic radiation

A type of background radiation associated with increased amounts at higher geographic elevations.

Conical PID

A type of position-indicating device (PID) that produces excess scatter radiation.

1 in 1 million risk

The lethal risk level associated with activities such as riding 10 miles on a bike, 300 miles in an auto, or 1000 miles in an airplane.

Gray (Gy)

A unit of radiation equivalent to $100\,rad$.

Total dose

Refers to the total amount of radiation that is received or absorbed.

Indirect theory

A theory of radiation injury proposing that toxins are created from the formation of free radicals.

16-inch rectangular PID

The type of position-indicating device most effective in reducing patient exposure.

Medical radiation

The single largest contributor to artificial radiation exposure, measured at approximately $0.00053\,Sv/year$.

Erythema

Reddening of the skin; a sign of excessive radiation exposure that would require more than 30 exposures using film in a 14-day period.

ALARA

An acronym for 'as low as reasonably achievable,' representing the concept that all radiation must be kept to a minimum.

Direct theory

A theory of radiation injury involving damage to critical areas of a cell through direct contact with an x-ray photon.

Added filtration

The placement of filters in the dental x-ray tubehead that results in a more penetrating useful beam.

Radiation monitoring

A protective measure for the dental radiographer that includes monitoring both equipment and personnel.