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)