Chapter #38
What are the primary components of a dental x-ray machine?
1. Tube head 2.extension arm 3. control panel
What two parts make-up an atom?
1. central nucleus 2. orbiting electrons.
What is usually found in the control panel?
1. master switch, 2. indicator lights,3.selector buttons,4. exposure buttons
What is the maximum permissible dose of radiation for occupationally exposed person?
5.0 rems/year
During the production of x-rays how much energy is lost as heat?
99%
Who was the first person to make practical use of x-rays in dentistry?
C.Edmund Kells
What is meant by the genetic effects?
Damage to genetic cells is passed on to succeeding generations.
What is the name of the process that results in the harmful effects of x-rays?
Ionization
What is a molecule?
Matter that is composed of atoms grouped together in a specific arrangement.
What are the 3 types of radiation?
Primary, Secondary, Scatter
What is ionization?
Process by which electrons are removed from atoms, causing harmful effects of radiation in humans.
What does radiolucent mean?
Structures that radiation can pass easily through appear dark on an image.
What does radiopaque mean?
Structures that radiation does not easily pass through appear white or gray on an image.
What are the two systems of radiation measurement?
Traditional system & Systeme Internationale
What is the most effective measure in reducing a patients exposure to radiation?
Using a fast-speed film is the most effective method.
Who discovered x-rays?
Wilhelm Conrad Roentgen
What exposure controls contrast?
a range of shades from black to white with multiple shades of gray. kilovoltage controls the exposure.
What is the positive electrode inside the x-ray tube?
anode
What is atoms?
are the basic form of matter, and they contain energy.
What is the negative electrode inside the x-ray tube?
cathode
What is matter?
is anything that occupies space and has form or shape.
What is energy?
is defined as the ability to work. energy cannot be created or destroyed, it can change form.
What is meant by density?
is the overall blackness or darkness of a film. is also controlled by milliampere.
What is the purpose of the aluminum filter?
is to remove the low energy, long-wavelength, least-penetrating x-rays from the beam.
The term image receptor?
is used when referring to either a digital imaging device or to film cause its recorded on or the other.
What is the name of the time period between x-ray exposure and the appearance of symptoms?
latent period
What precautions should be taken when one is handling the lead apron?
must be used on all patients for all exposures.
What is the purpose of the collimator?
to restrict the size and shape of the x-ray beam to reduce patient exposure.
Radiation
which is used to produce all types of dental images, has the ability to cause damage to all types of tissues. "No matter how small".
What is the heart of the x-ray generating system?
x-ray tube
