Xray - Week 10 PP Flashcards
Intraoral Film
Composed of:
-Paper wrapper
-Lead Foil
-Outer Package wrapping
Outer Wrapping has 2 sides:
TUBE Side - solid white (raised dots)
LABEL Side - coloured, contains flap to open packaging (inverted dot)
XRay Film Packet
1a - outer plastic/vinyl / paper wrapping (protects film from saliva)
2b. Black paper wrapping (protects emulsion)
- Xray Film (sensitive component)
2 (b) Black paper wrapping
- Lead foil/sheet (prevents backscattering of radiation - reduces patient exposure)
- b - Outer plastic/vinyl
Tube side of traditional film
TUBE SIDE – DOT is a BUMP
LABEL SIDE – DOT is FLAT
X-Ray Film Composition
- Film Base - Polyester plastic, provides support and strength.
- Adhesive Layer - Attaches emulsion to base.
- Film Emulsion - A mixture of gelatin and silver halide crystals (sensitive to radiation).
- Protective Layer - protects emulsion from damage.
What is Halide?
** Halide is a chemical compound that is sensitive to radiation. Silver halide is used in dental radiographs
3 Different types of conventional film
- intra oral - placed inside the mouth
- extra oral - taken outside of the mouth
- Duplicating - produces 2 copies of the same image (special film)
Latent Image
Film that has been exposed to radiation and has not yet been developed
Silver halide crystals (coating on film) contain various levels of stored energy, depending on the density of the objects in the area exposed.
The stored energy forms a pattern known as the latent image.
The latent image cannot be seen until chemical processing occurs to produce a visible image.
Film Sizes
Size 0 - 2-4 year olds
Size 1 - for child or adult anterior teeth
Size 2 - Adult posterior / bitewings
Size 3 - not used very often
Size 4 - occlusal
Film Speed (sensitivity) is determined by:
Film speed (sensitivity) is determined by:
1. Size of the silver halide crystals
2. Thickness of the emulsion
3. Presence of radiosensitive dyes
Speed ratings are from A-F (A is slowest, F is fastest)
ONLY D, E, F speed film is used for intra oral radiology
Extra Oral Film
There are two types of Extra Oral Films that are placed outside the mouth for xray exposure.
- Screen - film placed between 2 intensifying screens for exposure
- Film is exposed directly to xrays requires longer exposure time, NOT recommended for use in dentisty.
Duplicating Film
Photographic film used to make an identical copy of an intraoral or extraoral radiograph
Used only in a darkroom setting and is NOT exposured to radiation - exposed to LIGHT
Film Storage
Film must be kept in a cool, dry place (at SAIT we keep our film in the fridge)
- Must be stored in an area adequately shielded from radiation
- Film MUST be used before expiration date (can cause fogged films)
Processing Traditional Film - Responsibilities of a DA
- Process films/image
- Keep records of processed films/images
- Maintain the darkroom - the chemicals
- Maintain processing equipment
Importance of Film Processing
The use of traditional film is still currently being used in dental practices, although increasing numbers of dentists have transitioned from film-based to digital imaging, many offices still rely on film and processing.
Film processing procedures directly affect the quality of a dental radiograph. As a dental assistant, it is important to have a working knowledge of film processing procedures, problems, and solutions.
Film Processing refers to..
Film processing refers to a series of steps that produce
a visible permanent image on a dental radiograph.
The purpose of film processing is:
- To convert the latent (invisible) image on the film into a visible image.
- To preserve the visible image so that it is permanent and does not disappear from the dental radiograph.
Film Processing Techniques
- Manual (hand processing) – requires a dark room and processing solutions. ( not recommended as it is very technique sensitive)
- Automatic processing is the automatic film processing machine or automatic processor.
A variety of automatic film processors are commercially available.
Manual & Automatic Processing - 5 Steps in Processing
- Development
- Rinsing
- Fixing
- Washing
- Drying
Manual Processing - dark room
-Manual processing must be completed in a darkroom
-Any white light that “leaks” into the darkroom (e.g., from around a door or through a vent) is termed a light leak.
In a dark room, when all the lights are turned off and the door is closed, no white light should be seen.
-Any white light coming around the door, through a vent or keyhole, or through a wall or ceiling seam is a light leak and must be immediately corrected with weather stripping or black
tape. (white light affects the film)
Manual Processing - Safe lighting
The special type of lighting used to provide illumination in the darkroom is termed safe lighting. It is a low-intensity light ( 15 watts or less) composed of long wavelengths in the red-orange portion of the visible light spectrum. Safe lighting provides sufficient illumination in the darkroom to carry out processing activities safely without exposing or damaging the film.
Under safelight conditions, it is necessary to maintain an adequate safelight illumination
distance of a minimum of 4 feet
A film exposed to the safe light for more than 2 to 3 minutes will appear fogged.
Automatic Film Processor
Automatic processors can be used in a dark
room or use a daylight loader (SAIT)
How an Automatic Processor Works
- Feed film into feed slot
- Goes for a “ride” (on rollers, conveyer belt) and dips into developer solution
Total time to develop is about 4-6 minutes
Automatic Processing vs Manual processing
Total processing time is 4-6 minutes vs up to one hour with manual processing
Benefits of Automatic Processing
- Less processing time is required - because solutions are warm, they work faster
- Time and temperatures are automatically controlled - thermostats in machine, kept at proper temp
- Less equipment is used
- Less space is required
- Chances of errors in processing are reduced - since everything is all automatic
Automatic processing is what is used at SAIT
Processor Maintenance
- Processor chemicals should be checked and topped up daily
- Processing solutions should be replaced every 2-6 weeks (this can depend on the number of films being processed)
- The rollers within the processor should also be cleaned weekly (dependent on manufacturer instructions).
To do this the rollers are removed and rinsed in warm running water and then soaked for 10-20 minutes
Cleaning film can also be used at the beginning of each day to remove any residual gelatin or dirt on the rollers.
Always follow manufacturer instructions
Film Duplication
An identical copy of an intraoral or an extraoral radiograph is made through the proccess of film duplication. Dupicate radiographs may be used when referring patients to specialists, for insurance claims, and as teaching aids.
Before duplication occurs, the films are to be duplicated, the duplicating film, and the film
duplicator must be present in the darkroom. Similar to film processing, film duplication must
take place in a light-tight darkroom.
Processing problems may occur for a number of reasons, including the following:
- Time and temperature errors - too cold, too hot
- Chemical contamination errors - wrong mixture
- Film handling errors - when taking the film, did something wrong
- Lighting errors
As a dental assistants it is important, we understand what actions are needed to prevent these errors
Time and Temp Error Error: Underdeveloped film
Appears Light
Problems:
-Inadequate development time
Developer solution too cool
-Inaccurate timer or thermometor
-Depleted or contaminated developer solution
Solutions:
-Check development time
-Check developer temperature
-Replace faulty timer or thermometer
-Replenish developer with fresh solutions as needed
Time & Temp Error: Overdeveloped film
Appears Dark
Problems:
-Excessive developing time
-Developer solution too hot
-Inaccurate timer or themometer
-Concentrated developer solution
Solutions:
-Check development time
-Check Developer temperature
-Replace faulty timer or thermometer
-Replenish Deveoper with fresh solutions, as needed
Time & Temp Error: Reticulation of emulsion
Appears Cracked
Problem:
-Sudden temperature change between developer and water bath
Solution:
-Check temperature of processing solutions and water bath; avoid drastic temperature differences
Chemical Contamination Errors: Developer Spots
Appears - dark or black spots
Problems:
-Developer comes in contact with film before processing
Solution:
-Use a clean work area in the darkroom
Chemical Contamination Errors: Fixer Spots
Appears - White or light spots
Problems - fixer comes in contact with the film before processing
solutions - Use a clean work area in the dark room
Labeling Films/Images
Conventional films MUST be labeled once they have been developed on the film
mount as well as documented in the patient chart
- Record patient’s first and last name
- Date they were taken
- Type of radiograph(s) and how many
- Name of the Dentist or Hygienist who prescribed.
Automatic Film Processing Steps
- Prepare the darkroom
-if a daylight loader is not part of the automatic processor, the films must be processed in the darkroom
-Closer and lock the darkroom, turn off the overhead white light, and turn on the safelights - Prepare the films
-For intraoral films, carefully unwrap each exposed film over a clean work surface using proper infection prevention procedure
-Diposed of all film packet wrappings and recycle lead foil
-For extraoral films, carefully remove the film from the cassette
-Handle all films by the edges only - Insert the films
-Insert each unwrapped film into the film feed slot of the processor, one at a time
-Allow atleast 10 seconds between insertions of the films
-Alternate sides or slots, whenever possible
-Make certain that films are straight when inserted. (When films are turned sidways or inserted too quickly, overlapping may occur during processing. Overlapped firlms result in non-diagnostic radiographs). - Process and retrieve the films
-After the films have been inserted into the automatic processor, allow 4 to 6 minutes for automated processing to occur.
-Retrieve the processed radiographs from the film recovery slot on the outside of the automatic processor
Film Duplication
- Arrange the original set of processed films in anatomic order
-Place the dental radiographs to be duplicated on the light screen of the film duplicator
-Use manufacturer-supplied film organizers to arrange the films and block out extraneous light - Place the duplicating film
-Place the duplicating film on top of the arranged set of film
-Make certain the emulsion side is down on the duplicating film. Note: The emulsion side will appear dull and gray or lavender in color - Secure the duppicator lid
- Close the lid of the film duplicator and fasten it securely to ensure adequate contact between the original films and the duplicating films. Note: to prevent blurring of the image, good cotact must be maintained between the duplicating film and the firlms that are being duplicated
-Without good contact, the duplicate film appears fuzzy and shows less detail than the orignal film - Set the timer
-Select the exposure time, set the adjustable time, and activate the light sourse to expose the duplicating film. Note: An adjustable timer on the film duplicator controls the exposure time
-The adjustable timer controls the amount of light emitted from the film duplicator; the light passes through the original films and exposes and dupicate the film. The longer the duplicating film is exposed to light, the lighter it appears. This is the opposite of xray film; xray film appears darker with longer xposure to light.
-Exposure Time depends on the type of dupicator used and the density o the orginal films being duplicated. - Process the duplicating film
-Process the duplicating film using manual processing techniques or the automatic processor - Lavel the duplicate radiograph.
-Label the processed dupicate radiographs iwth the patient’s name and date of exposure.
-Also, label the radiographs to indicate the patient’s right (R) and left (L) sides.
Chemical Contamination Errors - Yellow-brown stains
Appears - yellow-brown colour
Problems:
-exhausted developer or fixer
-insufficient fixing time
-insufficient rinsing
Solutions:
-Replenish chemicals with fresh solutions, as needed
-use adequate fixing time
-rinse for a minimum of 20 mins
Film Handling Errors: Developer cutoff
Apearance - straight white border
Problem: Underdeveloped portion of film caused by low level of developer
Solution - Check developer level before processing: add solution if needed
Film Handling Errors: Fixer cutoff
Appearance: Straight black border
Problem: Unfixed portion of film caused by low level of fixer
Solution - Check fixer level before processing; add solution if needed
Film Handling Errors: Overlapped Films
Appears: White or dark areas on film where overlapped
Problem - Two films contacting each other during processing
Solution - Separate films so that no contact takes place during processing
Film Handling Errors - Air bubbles
Appears - white spots
Problem - Air trapped on the film surface after being placed in the processing solutions
Solution - Gently afitate film racks after placing in processing solutions
Film Handling Errors - Fingernail Artifact
Appears - black cressent shaped marks
Problem - Film emulsion damaged by operator’s fingernail during rough handling
Solution - Gently hand films, holding them on edges only
Film Handling Errors - Fingerprint artifact
Appears - Black fingerprint
Problem - film touched by fingers that are contaminated with fluoride or developer
Solution - Wash and dry hands thoroughly before processing films
Film Handling Errors - Static Electricity
Appears: thin black branching lines
Problems:
-Occurs when a film packet is opened quickly
-Occurs when a film pack is opened before radigrapher touches a conductive object
Solution - Open film packets slowly
-Touch a conductive object before unwrapping films
Film Handling Errors: Scratched film
Appears: White lines
Problem: Soft emulsion removed from film by a sharp object
Solution: Use car when handling films and film racks
Lighting Errors: Light Leak
Appears: Exposed area appears black
Problems: Accidental exposure of film to white light
Solutions - Examine film packet for defects before using
Lighting Erros: Fogged film
Apperance: Gray; lack of detail and contrast
Problems:
-improper safelighting
-light leaks in darkroom
-outdated films
-improper film storage
-contaminated solutions
-Developer solution too hot
Solutions:
-Check filter and bulb wattage of safelight
-Check darkroom for light leaks
-Check the expiration date on film packages
-Store films in a cool dry protected area
-Avoid contaminated solutions by covering tanks after each use
-Check temperatures of developer
How an Automatic Processor Works
Film feed slot – where film is inserted
Roller film transporter - The primary function is to Transport the film through the processor and helps to remove excess solutions on the film.
Developer compartment - Holds the developer solution which is a special chemical solution for high temp processing between 80°F and 95°F
Fixer compartment - Holds the fixer solution, which has chemical hardening agents that fix and harden.
Water compartment - Holds circulating water that washes the film after the fixer to remove all excess solutions.
Replenisher pumps/solutions - The pump and solutions are required to maintain proper solution concentration and levels automatically in some automatic processors, whereas other processors require the operator to add the necessary replenishing solutions.
Drying chamber - Holds heated air and is used to dry the wet film.
Film recovery slot - An opening on the outside of the processor housing where the dry, processed radiograph emerges from the automatic processor.
Total processing time is 4 to 6 mins
Note * The solutions that are used in an automatic processor are not the same as manual processing solutions.
