Dental Radiography and Radiation Safety Complete Practice Set

A comprehensive collection of 300 vocabulary flashcards covering the entire Dental Radiography and Radiation Safety transcript, including physics, imaging techniques, biology, safety protocols, and digital advancements.

Electromagnetic radiation (ER)

A group of energies that includes x-rays, radio waves, television waves, radiant heat, microwaves, visible light, and gamma radiation.

Radiation

The ability to transmit energy through space.

Speed of light

$$186,000\,miles\,per\,second$$

Mass and weight of electromagnetic energies

Energies within the electromagnetic spectrum consist of pure energy and have no mass or weight.

Penetrate matter

One of the specific properties of x-rays that make them useful for imaging in dentistry and medicine.

Latent image

An invisible image produced by x-rays in phosphors and film that becomes visible after processing.

Fluoresce

The ability of x-rays to cause certain materials, such as screens, to emit light.

Ionize

The ability of x-rays to convert substances (like water in humans) into ions.

Energy

The capacity for doing work or overcoming resistance.

Photon

A packet of energy or a single unit of x-ray radiation.

Wave-length

The distance between the peak or crest of one wave and the peak or crest of the adjacent wave.

Wavelength and energy relationship

Longer distance between wavelengths results in less energy/penetration; shorter distance results in greater energy/penetration.

Atoms

The basic building blocks of all substances in the universe.

Building blocks of atoms

Protons, electrons, and neutrons.

Mass

The scientific term used to describe the specific weight of atomic particles.

Nucleus

The central core of an atom composed of protons and neutrons.

Protons

Positively-charged particles found in the nucleus of an atom.

Neutrons

Neutral particles with no charge found in the nucleus of an atom.

Electrons

Negatively-charged particles that revolve around the nucleus in specific orbits.

BEIR V

The fifth in a series of books on the Biologic Effects of Ionizing Radiation developed by experts.

Stable Atoms

Substances with an equal number of electrons (-) and protons (+), resulting in a net charge of zero.

Molecule

A new substance formed when two atoms unite or bond together.

Ion

A charged particle with either a positive (+) or negative (-) charge.

Ionizing radiation

Radiation sufficiently energetic to dislodge electrons from an atom.

Non-ionizing radiation

Forms of radiation that do not produce ions when passing through substances.

Indirect damage

Biological damage in humans caused by the ionization of water (splitting the $H_2O$ molecule) by x-rays.

Free radicals

Highly unstable and short-lived molecules produced by the ionization of water that can act as cellular poisons.

Hydrogen peroxide

A cellular poison represented as $H_2O_2$, produced as a result of free radical recombination.

Hydroxyl radical

An example of a free radical denoted as $HO$.

Standard International Units (SIU)

Preferred radiation measurement units including Coulomb per kilogram, Gray, and Sievert.

Traditional units of measurement

Older radiation units including the röentgen (R), rad, and rem.

Röentgen (R)

The traditional unit used to measure the degree of ionization in the air.

Coulomb per kilogram (Coul/kg)

The Standard International Unit (SIU) equivalent for the röentgen.

A measurement of one röentgen

Indicates the quantity of radiation ions in a volume of air, but not the area of exposure or quantity absorbed by the body.

Rad

Traditional unit of absorbed dose, an acronym for "radiation absorbed dose."

Gray (Gy)

The Standard International Unit (SIU) equivalent for the rad.

Dose absorbed per gram

As measured by rads or Grays, the measure of energy absorbed per gram of substance or tissue.

Rem

Traditional unit used to equate the effects of differing kinds of ionizing radiation; acronym for "roentgen equivalent mammal."

Sievert (Sv)

The Standard International Unit (SIU) equivalent for the rem.

Units of dose equivalent

Classification for Sieverts and rems.

Rule of Thumb for x-radiation

In practical terms for x-radiation only, one Gray equals one Sievert.

Conversion: 1 Gy

$$100\,rads$$

Conversion: 1 Sv

$$100\,rems$$

Milli-

A prefix indicating one-thousandth ($.001$) of a unit.

Micro-

A prefix indicating one millionth ($.000001$) of a unit.

Density

The degree of darkness or overall blackness on a processed radiographic image.

Contrast

The difference in gradation of shades of gray on an individual radiographic image.

Electricity

The flow of electrons through a conductor.

Current

Relates to the number of electrons flowing through a wire or conductor.

AC (Alternating Current)

Current where the flow of electrons changes direction; typical household current is $60\,Hz$.

DC (Direct Current)

Current where electrons flow in only one direction; preferred for contemporary x-ray machines.

Amperage

The rate of flow of charge in a conductor per second of time.

Ampere

The standard unit for measuring the strength of an electric current.

Milliampere (mA)

One thousandth of an ampere; used to measure x-ray unit current.

Dental mA range

Intraoral and panoramic x-ray machines typically operate between $7$ and $15\,mA$.

Milliamperage function

Determines the quantity or total number of x-ray photons produced.

Milliamperage Seconds (MAS)

The product of the milliamperage and the exposure time in seconds.

MAS effect on density

Different mA and time settings resulting in the same mAs will produce the same image density.

Radiopaque

White or light areas on an image where x-rays were stopped or attenuated by dense material like metal.

Radiolucent

Dark or black areas on an image where x-rays penetrated through less dense structures like pulp.

Voltage

The electrical pressure or force applied to move electrons across a conductor, measured in volts.

Kilovolt (kV)

One thousand volts.

Dental kV operating range

Generally ranges from $65$ to $90\,kilovolts$. ($65$ to $90\,kV$).

Kilovolt peak (kVp)

The highest voltage an alternating current attains during each cycle.

Kilovoltage function

Determines the energy or penetrating power of the x-ray photon.

Soft x-rays

X-rays with low energy produced by the x-ray unit that are removed by aluminum filtration.

Relationship: kVp and patient dose

Greater kVp results in less radiation dose to the patient's skin because x-rays penetrate through the tissue more effectively.

High contrast

Also called short scale contrast; produced by low kilovoltage (e.g., $65\,kV$) and shows fewer shades of gray.

Low contrast

Also called long scale contrast; produced by high kilovoltage (e.g., $90\,kV$) and shows many shades of gray.

Cathode

The negatively charged electrode in the x-ray tube containing a filament wire.

Thermionic emission

The process where electrons are "boiled off" a heated filament wire to form an electron cloud.

Focusing cup

A negatively charged component that concentrates and directs electrons toward the tungsten target.

Tungsten target

The material embedded in the copper anode that serves as the positive terminal and is bombarded by electrons.

Focal spot

The small part of the anode target bombarded by electrons where x-rays are produced.

Energy Conversion at Target

$99\%$ of the energy is converted to heat, while only $1\%$ produces actual x-rays.

Copper Anode

Provides structural support for the target and conducts massive amounts of heat away during x-ray production.

Radiator

Helps dissipate heat from the copper anode into the surrounding x-ray tubehead.

Glass Envelope

The vacuum tube that surrounds internal components and prevents air from impeding electron movement.

Oil (in tubehead)

Serves as an electrical insulator and a heat dissipator generated at the target.

Pulse

A unit of time equal to $1/60th$ of a second.

Formula: Seconds to pulses

$$Time\,in\,seconds \times 60 = Time\,in\,pulses$$

Dead-man switch

A safety feature requiring continuous pressure for x-rays to be produced; generation stops if the button is released.

Transformer

An electrical device used to raise or lower electrical voltage.

Step-up transformer

Associated with kilovoltage; provides the high voltage needed to pull electrons to the tungsten target.

Step-down transformer

Associated with the mA circuit; regulates the voltage to the filament to boil off electrons.

Primary rays

X-rays emitted from the tungsten target of the x-ray tube used to make the clinical image.

Secondary (scattered) radiation

Occurs when the primary beam enters the patient and causes interactions not associated with the image receptor.

Bremsstrahlung radiation

The primary type of radiation emitting from the tubehead; German word meaning "breaking."

Coherent scattering

One of the three ways x-rays can interact with matter.

Compton effect

One of the three ways x-rays can interact with matter involving scattering.

Photoelectric absorption

One of the three ways x-rays interact with matter involving total absorption.

Cytoplasm

The living substance filling a cell, enclosed by the cell membrane.

Mature erythrocyte

The only mature human blood cell that does not contain a nucleus.

Direct effect

Primary biologic damage from ionizing radiation occurring within the cell nucleus or cytoplasm.

Somatic cells

Include all body cells except genetic reproduction cells (egg and sperm).

Genetic cells

Egg and sperm cells involved in the reproduction of the organism.

Highly specialized cells

Cells slow to reproduce, like mature bone, muscle, and nerve, which are most resistant to radiation destruction.

Small lymphocyte

A type of white blood cell that is one of the most radiosensitive somatic cells due to continuous reproduction.

Genetic mutations

Biologic effects that cannot be repaired and are passed down to future generations.

Natural background radiation

Sources include radon, cosmic rays, and building materials; accounts for about $66\%$ of genetic dose.