Lec 4 Film Imaging Flashcards
The most widely used receptor system in dentistry.
X-ray film
Composition of the x-ray film? (2)
1) Emulsion
2) Base
The ________ is sensitive to x-rays and visible light and records the radiographic image. The _______ is a plastic support onto which the emulsion is coated.
Emulsion; base
2 main components of the emulsion?
- silver halide grains
- vehicle gelatinous matrix
Silver halide grains
- Composed of primarily _____________ crystals 80% to 99%
- 1 – 10% __________
- silver bromide (AgBr)
- silver iodide (AgI)
- Suspends the silver halide grains.
- Absorbs processing solutions to reach and react with the silver halide grains.
- Acts as a barrier to protect film from scratching, contamination, or pressure from rollers of the automatic processor.
Vehicle gelatinous matrix
Supports the film emulsion.
Base
The base of the dental x-ray film is made up of?
Polyester polyethylene terephthalate
A thin layer of adhesive material that covers both sides of the film base.
Adhesive layer
- Thin transparent coating
- It serves to protect the emulsion surface from manipulation as well as mechanical and processing damage.
Protective layer
The intra-oral x-ray film is made up ____-emulsion film.
double-emulsion film
Is a small, raised bump in one corner of the film is used for orientation.
Identification dot
Identification dot:
- Convex side of dot means ____ side.
- Concave side of dot means towards ________.
- After exposure, during mounting, _______ side of the dot is toward the viewer.
- Convex side = tube side
- Concave side = patient’s tongue
- Convex side = viewer
Covers the film and shields from light.
Paper film wrap
Thin lead foil sheet is positioned behind the film to shield the film from backscattered (secondary) radiation that results in film fog
Lead foil sheet
Serves to protect the film from exposure to light and oral fluids.
Outer package wrapping
What are the 2 sides of the outer package wrapping?
Tube side, label side
- Tube side – faces the ____ and _________.
- Label side – contains the flap, color coded to distinguish one film or two film, when in the mouth, faces the _________.
- teeth and tubehead
- tongue
Records the crowns, roots, and surrounding bone
Periapical views
PERIAPICAL VIEWS:
- Size __ for small children (22 mm × 35 mm)
- Size __, which is relatively narrow and used for views of the anterior teeth (24 mm × 40 mm)
- Size __, the standard film size used for adults (30.5mm × 40.5 mm)
Size 0
Size 1
Size 2
Refers to the amount of radiation required to produce a radiograph of standard density.
Film speed
Larger the crystals, ___ (slower/faster?) the film speed
faster
An intraoral film speed is determined by? (3)
1) Size of the silver halide crystals
2) Thickness of the emulsion
3) Presence of special radiosensitive dyes
- They are used to detect interproximal caries and evaluate the height of alveolar bone.
- Coronal portion of maxillary and mandibular teeth are in one image.
Bitewing views
BITEWING VIEW:
- Size ___ film for adults,
- Size ___ for children.
- Size 2
- Size 1
A _________________ is used for patients to bite on.
paper tab or bitewing film holder
- It is used to show larger areas of the maxilla or mandible than may be seen on a periapical film.
- Patient bites lightly on the film to hold in place
- Shows right angle views.
Occlusal view
Occlusal views uses size?
Size 4
Extraoral films are also called as?
Screen films
Extraoral films are used in? (2)
cephalometric and panoramic views
Absorb x-rays and emit visible light, which exposes the film.
Intensifying screens
The pattern of stored energy on the exposed film cannot be seen and is referred to as?
Latent image
Irregularities in the lattice structure of the exposed crystal that attract the silver atoms?
Sensitivity specks
Is placed between two special intensifying screens in a cassette.
Screen film
Only __-speed, __-speed, ____speed, and __-speed (fastest) are used in intraoral dentistry
D, E, E/F, F
