How many shades of gray can the human eye appreciate?
32
A storage phosphor imaging uses a _______ imaging plate.
re-use-able imaging plate
What amount of exposure time reduction is a digital image compared to conventional radiography?
50-80%
What type of equipment is necessary to produce an image when using digital radiography?
Sensor and computerized imaging system
What are some ways that radiographic images are cleared from storage phosphor imaging plates?
Exposure to light and running through a scanner.
Can sensors be sterilized?
No
What nonmetallic restoration is the densest and least radiopaque?
porcelain
A well-adapted radiopaque restoration with smooth borders is probably?
Gold crown
What is the most common restorative material used in dentistry?
Amalgam
List some advantages of digital radiography?
-Superior gray scale resolution
-Reduced exposure to x-radiation
-increased speed of imaging viewing
-enhancement of digital imaging
-increased efficiency
-lower equipment cost
-Eco friendly
What types of objects should patients be instructed to remove for intraoral films?
-ant facial piercings
-glasses
-dentures/partials
What type of procedure would a patient have had performed is a post and cored can be seen on a radiograph?
Endo procedure
What is the most common reason that a dentist wants to take radiographs?
To detect carries
A thin radiopaque line outlining the prepared tooth may be invisible on a dental radiograph of an all porcelain crown. what does the thin line represent?
Cement
Which type of radiographs are used for the evaluation of caries?
Bitewings
These types of caries extend less than halfway through the thickness of the enamel.
Incipient carries
What diagnostic tool would a dentist use to detect caries that are not seen on a dental radiograph?
Explorer
What is the appearance of caries that are on the buccal or lingual surfaces of the teeth?
Appear circular-radiolucent area
These types of caries appear as a cupped-out or crater-shaped radiolucency?
Root surface caries
What is rampant caries?
Growing or spreading caries (Excessive amounts)
What are two causes of rampant caries?
-poor diet
-poor salivary flow
What type of exposure in general would you use to evaluate the TMJ?
-extraoral film (PAN)
What size is the most commonly used extraoral film?
5x7
An extraoral cassette would have the front side constructed of ______ and the backside constructed of _____.
plastic/metal
What is the fastest recommended screen and screen film combination?
rare earth and green light
What is a grid device?
Thin strip, reduces radiation.
Why are grids used?
-Reduces the radiation scatter.
-Decreases film fog
-increase contrast
What two areas are grids placed between?
Head and film
In panoramic radiography, the x-ray tube rotates around the patients head in one direction while the film rotates _____ direction.
opposite
Which exposure factors cannot be changed in panoramic radiography?
The exposure
What is the purpose of an intensifying screen in a cassette holder?
-help with scatter radiation
-reduce patient dose
-amplify incoming x-ray beam
How many intensifying screens are in a cassette?
2
What is the purpose of the occlusal technique?
exam the larger areas of the lower and upper jaw.
When using an occlusal film, how is it positioned in a patients mouth?
White side of film towards arch being exposed. Sandwich technique
A dental radiograph depicts which two dimensions of an object?
Length and width. it is a two-dimensional picture with a three-dimensional object.
What is the purpose of a calibration test for an x-ray machine?
Check to make sure there is no excess radiation leaks. Tests MA and KVP as well.
If the processed film appears clear with a slight blue tint, this indicates?
its properly stored and protected.
How do you test for light leaks in the darkroom?
Physical test-Shut off lights and close the door.
Using a coin test is a way that you are checking the proper distance of what piece of equipment?
The safelight
What is the purpose of a reference radiograph?
Used to compare the film density.
How often is a reference radiograph taken?
Daily
How often is a stepwedge taken?
Daily -used to determine developers strength
What is total dose?
Quantity of radiation received, or total amount of radiation energy absorbed.
Short-term radiation effects are associated with what two things?
-acute radiation
-Large amount of radiation absorbed in a short time.
What are somatic effects?
everything but genetic and not transmitted to future generations.
What is the traditional unit of dose for radiation?
-RAD : Radiation absorbed dose
What is the SI equivalent of the rem
Sievert (Sv)
What percentage of reduction is the F-speed film when compared to the D-speed film?
60% reduction
A longer source-to-film distance will reduce?
Reduce patient exposure to radiation.
Which is better? Rectangular or circular collimation?
Rectangular
Is there a set time between x-ray examinations for a patient?
No
A patient with gum disease will require______ frequent radiographic examinations.
More
Should radiographic procedures be limited for pregnant patients?
Yes
Who owns the original dental radiographs?
The dentist
The consumer-Patient radiation health and safety act is a ______ law.
Federal
What is a thyroid collar? And when is it used?
Protects thyroid gland and used in intraoral films. Can be separate or connected to a full lead apron.
Proper film processing after x-ray film exposure will reduce?
Patient exposure and amount of radiation
What are the degrees that the dental radiographer must be positioned at to avoid the primary beam?
90-135 degrees to the beam
Where should the radiographer wear a film badge?
belt line at the waist or by the collar.
What does ALARA stand for?
As low as responsibly achievable.
When the bisecting technique is used, the central ray is directed at 90 degrees to the?
imaginary bisector.
Why do you use a film folder when using the bisecting technique?
-Used to to position the receptor in the mouth and maintain it in position.
-Reduce radiation exposure.
What are the two commercially available holders that can be used with the bisecting technique?
Rinn BAI or Rinn XCP
In which x-ray techniques are the same principles of horizontal angulation used?
Paralleling , bisecting, and bitewing technique
What caused overlapping on a film/image?
Incorrect horizontal angulation
When images appear stretched out and distorted, this might be a cause of the FILM being?
It would be bent
When a FILM is creased what will appear on the image?
a radiolucent line
What is Phalangioma?
Finger on the film
A herringbone pattern is caused by a film being?
Being placed backwards in the mouth and appear lighter.
Electrons that can be visualized as being divided into an arrangement of blocks or picture elements are known as?
Pixels