Radiology: Chapter 7 Dental X-ray Film and Processing Methods
Size 3 film has a longer ______ dimension and will record more teeth than size 2 film
Horizontal
Developer contains two reducing agents:
Hydroquinone & Elon (Hydroquinone slowly to build density & elon is fast to build contrast)
What happens when gelatin is placed in liquid?
It swells and exposes the silver halide crystals to the chemicals in the developing solution
There are FIVE sizes of intraoral film, what are they? The larger the number, the larger the size
0, 1, 2, 3, and 4
Dental film emulsion is about __-__% silver IODIDE
1-10%
The basic steps of processing dental x ray films:
1. Developing 2. Rinsing (automatic processors often omit this step) 3. Fixing 4. Washing 5. Drying
What 4 things do film packets consist of?
1. Film (one or two films) 2. Black Paper Wrapping (adds additional light protection) 3. Lead Foil (located in the back, absorbs scatter radiation, clarity) 4. Moisture Resistant Outer Wrapping
The fixing steps: (3)
1. Stops further film development, establishing permanent imagine on film 2. Removes (dissolves) unexposed silver halide crystals 3. Hardens (fixes) the emulsion
Dental film emulsion is about ____-____% silver BROMIDE
90-99%
Silver halide crystals are compounds of a what?
A halogen (bromine or iodine) with another element
Rinsing preserves the _____ of the fixer and prolongs it's useful life
Acidity
Classified as screen film, is larger in size and designed for use outside the mouth
Extraoral film
What film speed has the greatest sensitivity to radiation
F
True or false Film size is found on the back side of the intraoral film packet
FALSE IT IS NOT
The LARGER the crystals, the ____ the film speed, resulting in less radiation
Faster
The American National Standards Institute (ANSI) groups film speed using letter of the alphabet: speed group A die the slowest through F, which is the _____ film available
Fastest
What provides support for the fragile emulsion and strength for handling x Ray film?
Film base
Small films suitable for intraoral radiography are made into what are called...
Film packets
After brief rinsing, the film is immersed into the what?
Fixer solution
Physical pressure and bending can ____ the film
Fog
The use of high speed film has made it possible to reduce patient exposure to radiation to a _____ of the time formerly deemed necessary
Fraction
During radiation, the x-rags strike and ionize some, but not all, of the silver halide crystals resulting in the formation of a...
Latent (invisible) image
During x Ray exposure, crystals within the film emulsion become energized with a...
Latent image
The faster the FILM SPEED, the _____ radiation required
Less
Silver halide crystals are ____ and ____ sensitive
Light and x Ray
Will all of the radiation penetrating the patient's tissue reach the film emulsion?
No
True or False The MAIN function of the GELATIN is to keep the silver halide crystals evenly suspended over the base
True
True or false All automatic processors require water
True
True or false Individual packets should also be kept in a shielded area
True
True or false Stray radiation can fog film
True
True or false The tube side is usually solid white, and the tab for opening the film packet is on the back side
True
The front side or ____ side of the film packet faves the tube (radiation source)
Tube
Fixing agent (clearing agent) that removes unexposed and any remaining undeveloped silver halide crystals (responsible for radiopaque appearance)
ammonium thiosulfate or sodium thiosulfate
______ is composed of gelatin
Emulsion
What largely replaces Manuel processing because of its ability to produce a large volume of radiographs in less time? (5 minutes)
Automatic film processing
The _____ side of the film packet faces away from the radiation
Back
What provides support for the fragile film emulsion?
Base
The role of the DEVELOPER solution is to reduce the exposed silver halide crystals within the film emulsion to _____ ____ ____
Black metallic silver
X Ray film is sensitive to white light and white light in the darkroom can _____ the film or cause it to fog
Blacken
After the film is completely fixed, it is washed in running water to remove any remaining traces of ______
Chemicals
The blue tint enhances ______ & _____ quality
Contrast and image
To prevent fogging, film should be stored in a ____, dry place, at what temperature?
Cool 50-70 degrees (30 to 50 humidity)
Currently, only what 3 speed films are available?
D, E, and F
Film fogging is the _____ of the finished radiograph caused by one or more of these factors
Darkening
Provides an area where x Ray films can be safely handled and processed
Darkroom
The ______ is especially subject to oxidation in the presence of air and loses its effectiveness quickly
Developer
In this case, the ______ and _____ with the oxygen in the air is what is causing oxidation
Developer and fixer
A thermometer is used for Manuel processing to determine the temperature of the...
Developer solution
During which step are the exposed silver halide crystals reduced to metallic silver?
Developing
Final step is _____ Films may be air dried at room temp or dried in a heated cabinet
Drying
The emulsion side appears ___ and ___ when observed under sage light conditions in the dark room
Dull and lighter
Different than x Ray film and is exposed by the action of infrared and ultraviolet light rather than by x rays
Duplicating film
To make a copy of a radiograph, the emulsion side of the film is placed against the original radiography with the _____ side up
Nonemulsion
Which side contains an antihalation coating?
Nonsmulsion side
How many sides of duplicating film is coated with emulsion?
One
Film should be stored in its original packaging in an area shielded from radiation
Original
Weakened chemistry occurs though _______, the union of a substance
Oxidation
Film used in dental radigraphy is _____ film that has been especiallt adapted in size, emulsion, speed, & packaging
Photographic
Films used in Dental radiography have a thin, flexible, clear, or blue-tinted ______ base
Polyester
This transforms the latent image, which is produced when the x Ray photons are absorbed by the silver halide crystals in the emulsion (invisible and stable)
Processing
All exposed films should be kept safe from ____ until processing
Radiation
All radiographic film is extremely sensitive to:
Radiation Light Heat Humidity Chemical fumes Physical pressure
Basically, the developer is responsible for creating the film's ____ appearance
Radiolucent
The purpose of the rinsing step is to remove as much of the ______ developer as possible before placing the film in the fixer solution
Rinsing
______ refers to the AMOUNT of radiation required to produce a radiograph of acceptable density
SPEED (sensitivity)
Exposed primarily by a fluorescent type of light given off by special emulsion coated intensifying screens
Screen film (indirect-exposure film)
Film is sensitive to AGING, having a ____ ____ determined by the manufacturer
Shelf life
The nonemulsion side appears ___ and ___ when observed under sage light conditions in the dark room
Shiny and darker
A supercoat later of gelatin does what as it dries to protect the emulsion from handling, leaving a SMOOTH SURFACE that becomes a radiograph
Shrinks
In radiography, as well as in I'll photography, the other element is what?
Silver
Most automatic processors consist of _____ tanks for the developer, fixer, water, and drying solution
Three
Emulsion is composed of gelatin, in which CRYSTALS of what are suspended?
Silver halide salts
What size film is especially designed for small children and is also called pedo or pedodontic film?
Size 0
What size film may also be used for children, but can be used for the anterior teeth on adults? (Ideal for places where oral cavity is narrow)
Size 1
What size film is generally standard or referred to as PA (periapical film) Used to take both periapical and bitewing radiographs in adults and children with large oral cavities
Size 2 (most selected size)
What size film comes with a preattached bite tab and is used exclusively to take bitewing radiographs?
Size 3
What film is the largest and are used exclusively for taking occlusal radiographs?
Size 4
** What factors can determine film speed? (3)
Size of silver halide crystals Thickness of the emulsion Addition of special radiosensitive dyes
Of these three factors, which is MOST important in increasing film speed?
Size of the silver halide crystals in emulsion
However, imagine sharpness is more distinct when the crystals are _____
Small
which ingredient removes the unexposed/undeveloped silver halide crystals from the film emulsion?
Sodium thiosulfate
When duplicating film is exposed to ultraviolet light from the duplicating machine, the ____ _____ records the copy
Solarized emulsion
Automatic processor has ability to regulate the _____ of the processing solutions and the time of the developing process
Temperature
If not thoroughly ____, chemicals will continue to react within the dried emulsion and degrade the image over time
Washed
Manuel processing can be used to produce a _____ ____ without a darkroom in about 30 seconds. (Rapid or chairside processing)
Working radiograph
Are silver halide crystals sensitive to radiation? (Retain the latent image)
Yes
Is the film speed printed on the back side of each individual film packet?
Yes
What is the function of the lead foil in the film packet?
absorb backscatter radiation
