Final Flashcards
What is the Compton effect?
The dental X-ray interacts with an orbital electron and ejects it.
What is secondary radiation?
Given off by any matter irradiated with X-rays. Craeted at the instant the primary beam interacts with matter and gives off some of its energy, forming new and less powerful wavelengths. Can also be referred to as secondary radiation.
What is radioactivity?
It is defined as the process by where certain unstable elements undergo spontaneous disintegration (decay) in an effort to attain a stable nuclear state.
What are the X-ray machine components?
The control pad which regulates devices. 2) the extension arm or bracket that enable the tube head to be positioned. 3) The tube head contains the X-ray tube from which the X-rays are generated.
What is the transformer?
It is an electromagnetic device for changing the current coming into the dental X-ray machine. Transformers are required to decrease (step-down) or increase (step up) the ordinary 110-V or 220 V current that enters the X-ray machine.
What is the autotransformer?
It is located at the control panel is a high voltage compensatory that corrects minor fluctuations in the current flowing through the wires.
What is contrast?
It refers to the many shades of grey that that separatee the light and dark areas.High is for caries and low is for peril.
What is ionization?
States that cell damage results when ionizing radiation directly hits critical areas within the cell.
What is indirect theory ?
states that cell damage results indirectly when X-rays cause the formation of toxins in the cello such as hydrogen peroxide. Toxins in turn cause the cell damage.
T/F one third of biological alterations from and x-radiation exposure result from a direct effect.
True
t/f two thirds of biological alterations occur from a radiation exposure result from indirect effects.
true
Threshold dose response curve?
indicates that there is a threshold amount of radiation below which no biological response would be expected.
Nonthreshold response?
indicates that any amount of radiation no matter how small is has the potential to cause biological response.
What is ionization?
The form of ion pairs. The delicate balance of the cell structure is damaged or destroyed.
Rectangular PID/
restrict the beam to a size #2
