Radiography Test Three Choter 8,9, 10,11, Q12, 13,14 Flashcards
Air space freely permits the passage of dental x ray and appears
Mostly radiolucent
Radiolucent
The portion of the radiograph that is black or dark.
Radiopaque
Portion of the processed radiograph that appears light or white.
Density
Overall blackness.
Today most modern machine do not allow for adjustment of
Milliamprage
Not being able to adjust the milliamprage results in
More x rays that the receptor is exposed to thus more density
Contrast
The difference in degrees of density ( blackness) between adjacent areas.
The difference in the amount of light transmitted through adjacent areas can also be called
Contrast
When viewed on a light source, a dental radiograph that has very dark areas and very little light areas is said to have
High contrast.
An increase in development time or development temperature results in a film with
High contrast
The range of useful densities seen on a dental radiograph is termed.
Scale of contrast.
The smaller the focal spot area
The sharper the image.
The larger the focal spot area
The greater is the loss of image sharpness.
Manual film processing also known as
Hand processing or tank processing
Manual film processings five steps
development, rinsing , fixing ,washing ,drying
The first step in manual processing
Development-chemical solution known as developer is used. The developer solution softens the film emulsion during this process.
To maintain freshness the processing solutions must be
Replenished daily and changed every 3 to 4 weeks .more frequent if large numbers of films are processed.
Developer solution Hydroquinone
Generates the black tones and the sharp contrast of the radiographic image
A non mercury thermometer
Goes in the developer, it is ness army to determine the temperature of the developer solution. A floating thermometer may be used.
The tank on the left is used for
Developer
The tank on the right is used for
The fixer
Cleaning film
An extra oral size cleaning film thatRemoves any residual gelatin or dirt from rollers.and must be ram through the processor at the beginning of each day
A safe light
Must be placed a minimume of 4 feet ( 1.2) away from the film and wrk area and unwrapped films must be processed immediately under safe light conditions
The duplication of films requires the use of
Film duplicator and duplicating film
A film duplicator is
A light source available through manufactures such as densply rinn corporation
A film duplicator provides a
Diffused light source
Underdeveloped film appears
Light
An over developed film appears
Dark
Chemical contamination on films such as developer spots:
Dark spots appear on film, are seen when the developer solution comes in contact with the film before processing. The solution is to use clean work are, can place a paper towel.
Fixer spots
Appearance: white spots on film
Problem:fixer solution come in contact with film befor processing
Static electricity
Thin black branching lines appears on the film
May result from opening a pack quickly.
A fogged film appears
Gray and lacks detal and contrast
Screens and cassettes : extra oral screens used with a cassette holder
Should be periodically examined for dirt and scratches. Screens should be cleaned monthly.
The view box
Contains fluorescent light bulbs that omits light through a plastic or plexiglass front
When functioning properly the view box
Should summit a uniformed and subdued light.
Proper safe lighting
The film should be unwrapped 4 ft away from safe light.
Fixer strength
Unwrap film place it in fixer take it out if it clears in2 minutes it adequate strength if it doesn’t then re immerse if the film doesn’t completely clear in 3 to 4 minutes the solution is depleted.
