By :
Maryam Mageed Nife
Nakheel Moaied Raheem
Masoma Mohammed Jaseem
Mohammed Zaki Habib
Mohammed Kareem Radhi
X-Ray Film
(Types & Indications)
X-ray films are the most widely used receptor system in
dentistry. This presentation will describes x-ray films
composition , types , sizes and indications.
Introduction
Extra oral X- Ray
film
Contents
X-Ray Film
Composition
Intraoral X-Ray
Film
X-Ray Film Composition
X-ray film has two principal components:
1- Emulsion
2- Base
Emulsion
The two principal components of emulsion are silver halide grains, which
are sensitive to x-radiation and visible light, and a vehicle gelatinous
matrix in which the crystals are suspended.
Scanning electron
micrograph of emulsion of
INSIGHT
film showing flat tabular
silver bromide crystals,
Scanning electron
micrograph of INSIGHT
dental x-ray film
Emulsion
The silver halide grains are composed primarily of crystals of silver
bromide. The silver halide grains in INSIGHT film and Ultra-speed film
are flat, tabular crystals with a mean diameter of approximately 1.8 μm
The tabular grains are oriented parallel with the film surface to offer a
large cross-sectional area to the x-ray beam. INSIGHT film has
approximately twice the number of silver grains so that it requires only
half the exposure of Ultra-speed film.
Base
The function of the film base is to support the
emulsion. The base for dental Xray film is
made of polyester polyethylene terephthalate,
which provides the proper degree of flexibility
to allow easy handling of the film.
Base
The film base must also withstand exposure to
processing solutions without becoming
distorted. The base is uniformly translucent
and casts no pattern on the resultant
radiograph.
.
1- Intra oral X- Ray film 2- Extra oral X- Ray film
Types of X-Ray Film
Intraoral X-Ray Film
Intraoral dental x-ray film is made as a double-emulsion film
(i.e., both sides of the base are coated with an emulsion). With
a double layer of emulsion, less radiation is required to
produce an image.
Intraoral X-Ray Film
Direct exposure film is used for intraoral examinations because
it provides higher resolution images than screen-film
combinations. Some diagnostic tasks, such as detection of
incipient caries or early periapical disease, require this higher
resolution.
One corner of each dental film has a small, raised dot that is used for
film orientation
(A) The raised film dot (arrow) indicates the tube side of the film and identifies the
patient's right and left sides. (B) The location of this dot is clearly marked with a
black circle on the outside of every film packet.
01
A thin lead foil backing with an embossed pattern is between the
wrappers in the film packet. The foil is positioned in the film packet
behind the film away from the tube. This lead foil serves several
purposes such as :
1- It shields the film from backscatter (secondary) radiation, which fogs
the film and reduces image contrast (image quality).
2- It reduces patient exposure by absorbing some of the residual x-ray
beam.
Types of Intraoral X-Rays film
Periapical View ( Type I)
Periapical views record the crowns, roots, and surrounding bone. Film packs come
in three sizes
• Size 0 for small children (22 mm × 35 mm)
• Size 1, which is relatively narrow and used for views of the anterior teeth (24 mm
× 40 mm)
• Size 2, the standard film size used for adults (30.5 mm × 40.5 mm)
Bite-Wing View ( Type II)
Bite-wing (interproximal) views record the coronal portions of the
maxillary and mandibular teeth in one image. They are used to detect
interproximal caries and evaluate the height of alveolar bone. Size 2 film is
normally used in adults; the smaller size 1 is preferred in children. In small
children, size 0 may be used. A relatively long size 3 is also available.
Bite-Wing View ( Type II)
Bite-wing films often have a paper tab projecting from the middle of the
film on which the patient bites to support the film. This tab is rarely
visualized on the image and does not interfere with the diagnostic quality
of the image. Film-holding instruments for bite-wing projections also are
available.
Occlusal View ( Type III)
Occlusal film, size 4, is more than 3 times larger than size 2 film. It is used
to show larger areas of the maxilla or mandible than may be seen on a
periapical film. These films also are used to obtain right-angle views to the
usual periapical view. The name derives from the fact that the film is held
in position by having the patient bite lightly on it to support it between the
occlusal surfaces of the teeth
Extra oral X- Ray film
The purpose of using such film is to make a radiographic
image able to examine an area in and around the jaw that can't
be seen by intra oral film, there are two types of extra oral
film :
1- Non screen film
2- screen film
Non screen film
1. Film emulsion is more sensitive to X- ray than to light.
2. The film has double emulsion like intra oral film but the emulsion is
thicker.
3. Increased thickness of emulsion make the non screen film need less
amount of radiation so it need less exposure time.
4. The size of the film used include: 5×7 and 8×10 inches.
Screen film
1. Film emulsion is more sensitive to visible light and more specifically to blue
light in the visible light spectrum.
2. The size include: - 5×7, 8×10 and 10×12 inches.
3. Screen film has 3 types:- slow or detail screen, medium or par – speed screen
and fast or high – speed screen.
4 .The screen film placed between 2 fluorescent screen in cassette. These 2
fluorescent screen made from (tiny calcium tungestate crystals). When these
crystals exposed to X- Ray , the result of this exposure is a creation of light , this
light in turn exposes the screen film to produce the image.
01
The extraoral projections used most frequently in
dentistry are panoramic and cephalometric views For
these projections, screen film is used with intensifying
screens to reduce patient exposure Screen film is
different from dental intraoral film. is designed to be
sensitive to visible light because it is placed between
two intensifying screens when an exposure is made.
01
The intensifying screens absorb x-rays and emit
visible light, which exposes the film. Silver halide
crystals are inherently sensitive to ultraviolet (UV)
and blue light (300 to 500 nm) and thus are
sensitive to screens that emit UV and blue light.
01
When film is used with screens that emit green
light the silver halide crystals are coated with
sensitizing dyes to increase absorption. It is
important to use the appropriate screen-film
combination recommended by the screen and
film manufacturer