Dental Radiography Flashcards

What is the maximum permissible dose (MPD) of radiation for an occupationally exposed dental worker per year according to NCRP guidelines?

Answer: 50 mSv (5 rem)

The NCRP recommends a maximum permissible dose of 50 mSv (5 rem) per year for occupationally exposed workers.

Which film placement error results in a foreshortened image on a periapical radiograph?

Answer: Excessive vertical angulation

Excessive positive (downward) vertical angulation causes the image to appear foreshortened, making teeth look shorter than they actually are.

Which radiographic landmark appears as a radiolucent oval area above the roots of the maxillary central incisors?

Answer: Incisive foramen

The incisive foramen (nasopalatine foramen) appears as a round or oval radiolucency located at the midline between the roots of the maxillary central incisors.

During fixer processing, what is the primary chemical action on the exposed radiographic film?

Answer: Removes unexposed silver halide crystals

The fixer solution removes unexposed and undeveloped silver halide crystals, clearing the non-image areas of the film.

Which dental condition would appear radiopaque on a radiograph?

Answer: Amalgam restoration

Amalgam restorations are highly radiopaque because the metal alloy absorbs X-rays, appearing white on the radiograph.

What does the term 'long-cone technique' refer to in dental radiography?

Answer: Paralleling technique using a 16-inch focal-film distance

The long-cone technique refers to the paralleling technique using a 16-inch (40 cm) focal-film distance to reduce image magnification.