Introduction to Dental Radiography and Equipment

Vocabulary flashcards covering the components, functions, and image types associated with dental x-ray equipment.

Tubehead

The tightly sealed, heavy metal housing that contains the x-ray tube that produces dental x-rays.

Metal Housing

The metal body of the tubehead filled with insulating oil that houses the x-ray tube.

Tubehead Seal

A seal made of leaded glass or aluminum that keeps oil in the tubehead and acts as a filter for the x-ray beam.

Transformer

A component in the tubehead that alters the voltage of incoming electrical current.

Aluminum Filter

An aluminum sheet $0.5\,\text{mm}$ thick located in the tubehead that filters the x-ray beam.

Lead Collimator

A metal disc with a small opening in the center used to control the size and shape of the x-ray beam as it leaves the tubehead.

Position Indicator Device (PID)

An open-ended, lead-lined cylinder extending from the tubehead housing used to aim the x-ray beam.

X-Ray Tube

A glass vacuum tube housing the cathode and anode electrodes where x-rays are produced with minimal resistance.

Cathode

The negative electrode in the x-ray tube consisting of a tungsten filament in a molybdenum focusing cup that supplies the electrons necessary to generate x-rays.

Anode

The positive electrode in the x-ray tube composed of a tungsten target embedded in a copper stem that acts as a target for electrons.

Tungsten Target

A small block of tungsten in the anode that serves as a focal spot to convert bombarding electrons into x-ray photons.

Central Ray

The x-rays located at the center of the useful x-ray beam.

Extension Arm

The component that encloses the wire between the tubehead and control panel, folding and swiveling to allow positioning of the tubehead.

Control Panel

The component of an x-ray unit containing the master switch, indicator lights, selector buttons, exposure button, and control devices for exposure factors.

Master Switch

The switch on the control panel used to turn the x-ray machine on and off.

Orange Indicator Light

The light on the control panel showing when the master switch is turned on.

Red Emission Indicator Light

The light on the control panel that illuminates only when the exposure button is pressed and x-rays are actively being emitted.

Impulses

Fractions of a second used to measure exposure time, where $60\text{ impulses} = 1\text{ second}$ and $30\text{ impulses} = 0.5\text{ seconds}$.

Milliamperage (mA)

A measurement of the electrical current passing through the tungsten filament.

Kilovoltage Peak (kVp)

The selector setting used to control the penetrating power of the x-ray beam.

Bitewing Image

An intraoral radiograph showing upper and lower teeth in occlusion, used to detect interproximal decay, periodontal disease, recurrent decay, and fit of restorations.

Periapical Image

An intraoral radiograph showing the entire tooth from the crown to $2\text{ to }3\,\text{mm}$ beyond the apex, used to examine pathologic conditions of the tooth, root, and bone.

Full-Mouth Examination (FMX)

A complete intraoral series usually containing $18\text{ to }20$ images ($14$ periapical and $4\text{ to }6$ bitewing views) for a comprehensive survey.