Module 4
Terms
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- X-ray film
- is extremely sensitive to visible white light.
- Intraoral film
- it is placed inside the mouth during x-ray exposure.
- Cephalometric radiograph
- tracings made from cephalometric radiographs will indicate the location of various planes and points of interest to the orthodontist
- Developing
- Developing is the first step in processing films
- Fixing
- The fixer also hardens the film emulsion during this process.
- Developing
- solution also softens the film emulsion during this process.
- Film Cassette
- A cassette is a plastic or metal case used in extraoral radiography to hold the film and protect it from exposure to light. Cassettes are available in rigid or flexible styles.
- Panoramic radiographs
- used to examine large areas of the face and jaws, locate impacted teeth, evaluate trauma, lesions and diseases of the jaw and to evaluate growth and development
- Automatic film processing
- Other than opening the film packet, the automatic processor automates all film processing steps.
- Panoramic radiographs
- can be made with the client sitting, standing or lying down depending on the type of equipment being used
- Panoramic radiographs
- Diagnosis is simplified because the teeth and anatomical structures are shown in a consecutive sequence, rather than in a series of individual radiographs
- Film Cassette
- To tell the patient's left from the right as on intraoral films, the front of the cassettes must be marked with lead letters "L" (left side) or "R" (right side).This is because there is no raised dot on extraoral film.
- Washing
- Following fixation, a water bath is used to wash the film.
- extraoral film
- Examples of common extraoral films include panoramic and cephalometric films.
- Film speed
- refers to the amount of radiation required to produce a radiograph of standard density (darkness).
- larger the crystals
- the faster the film speed. This is the same principal as film speed on photographic film.
- Processing Tanks
- Manual processing is a method that is used to develop, rinse, fix, and wash dental x-ray films.
- Cephalometric radiograph
- are commonly used by orthodontists for evaluation of the skull for prediction of future growth
- Fixing
- Leaving films in the fixer for a long time (e.g., over a weekend) can remove the image from the film.
- Rinsing
- This must be done under safelight conditions.
- Intensifying Screen
- The film inside the cassette is sandwiched between the intensifying screens and is affected by both the light produced by the phosphor and the x-radiation.
- Automatic film processing
- maintains the correct temperature of the solutions and adjusts the processing time
- Five Steps in Manual Processing of Dental Radiographs
- Development, Rinsing,Fixation, Washing ,Drying
- film feed
- slot is for the unwrapped films to be inserted into the automatic processor
- Washing
- The washing step requires about 20 minutes to thoroughly remove all excess chemicals from the emulsion.
- Fixing
- The acidic fixing solution removes the unexposed silver halide crystals from the film emulsion.
- Automatic film processing
- requires only 4 to 6 minutes to develop, fix, wash, and dry a film, whereas manual processing techniques require approximately 1 hour.
- Film speed is determined by the following:
- The size of the silver halide crystals, The thickness of the emulsion, The presence of special radiosensitive dyes.
- Intraoral film
- To protect the film from light and moisture, the film is packaged and referred to as the film packet.
- Fixing
- For permanent fixation, the film is kept in the fixer for a minimum of 10 minutes.
- roller film transporter
- is a system of rollers that rapidly moves the film through the compartments.
- Developing
- A chemical solution called the developer is used
- Panoramic radiographs
- in addition to providing an extensive view of dento-maxillo-facial structures it is popular because of simplicity of operation, client comfort and reduced radiation exposure
- Panoramic radiographs
- are unique extraoral films that show the entire dentition and related structure from condyle to condyle on a single film
- Extraoral radiographs disadvantage
- they do not have detail and definition of intraoral radiographs
- Film Processing Solutions
- Powder, Ready-to-use liquid, Liquid concentrate
- Extraoral dental radiographs
- are produced by exposing dental radiographic film that remains outside the clients mouth
- Processing Tanks
- is divided into compartments to hold the developer solution, water bath, and fixer solution.
- developer and fixer compartments
- holds the solutions.The film is transported directly from the developer into the fixer without a rinsing step.
- Extraoral films
- provides a view of the entire tooth bearing area of the face and allows the viewer to see large areas of pathology or fractures
- Intensifying Screen
- intensifies or increases the effect of the radiation and thus decreases the amount of exposure time needed.
- Processing Tanks
- The essential piece of equipment required for manual processing is a
- Rinsing
- the films is necessary to remove the developer from the film so that the development process stops.
- Room lighting
- An overhead white light that provides adequate lighting when performing tasks such as cleaning, restocking materials, and mixing chemicals is required.
- Fixing
- However, films may be removed from the fixing solution after 3 minutes for viewing.
- Intensifying Screen
- is coated with a material called phosphor that gives off light when struck by x-radiation.
- Drying
- Films may be air-dried at room temperature in a dust-free area or placed in a heated drying cabinet.
- Processing Tanks
- has two insert tanks and one master tank.
- Intensifying Screen
- However, there is a slight loss of image detail as a result of the intensified x-ray beam because the light produces a halo effect at the edge of the image field.
- Automatic film processing
- is a fast and simple method used to process dental x-ray films.
- Fixing
- Films that are not properly fixed will fade and turn brown in a short time.
- panoramic film
- shows a panoramic (wide) view of the upper and lower jaws on a single radiograph.
- Lateral Oblique jaw radiograph
- An extra-oral radiograph of either side of the client face that produces an image of both the maxilla and mandible on the same film
- cephalometric film
- shows the bony and soft tissue areas of the facial profile.
- Processing Tanks
- showing developing and fixing tanks inserts in bath of running water.
- Safelighting
- A safelight is a low-intensity light in the red-orange spectrum. Safelighting provides enough illumination in the darkroom to process films safely without exposing or damaging the film.
- Automatic film processing
- Providing the automatic processor is maintained properly, there is less chance of errors during film processing.
- Cephalometric radiograph
- the data are used to measure existing conditions and compare them with future or desirable conditions
- Rinsing
- Usually, agitating the film rack for 20 seconds is sufficient.
- Safelighting
- Unwrapped films that are left too close to the safelight or exposed to the safelight for more than 2 to 3 minutes appear fogged.
- extraoral film
- are used to examine large areas of the head or jaws.
- Drying
- The final step in film processing is the drying of the films.
- Automatic film processing
- Many dental offices that have automatic processors still maintain manual processing equipment as a stand-by if the automatic processor malfunctions.
- Extraoral dental radiographs
- these films are not limited to the size of the client mouth, but will show the entire head or both the maxilla and mandible and provide a general overview of structures and their relationships
- extraoral film
- is one that is placed outside of the mouth during x-ray exposure.
- Developing
- The purpose of the developer is to chemically reduce the exposed silver halide crystals into black metallic silver.
- Cephalometric radiograph
- An extraoral radiograph showing lateral and posterioanterior view of the head
- Cephalometric radiograph
- are less used in prosthodontic treatment
- X-ray film
- Any leaks of white light can cause film fog. A fogged film appears dull gray, lacks contrast, and is nondiagnostic.
- water compartment
- holds circulating water.
- drying chamber
- holds heated air and dries the wet film.
- Film Cassette
- The front side of the cassette must always face the patient during exposure.
- Drying
- Films must be completely dried before they can be handled for mounting and viewing.
- Safelighting
- A safelight must be placed a minimum of 4 feet away from the film and working area.
- Cephalometric radiograph
- They also used by oral surgeons for the treatment planning purposes in orthognathic surgery
- Intraoral film
- x-ray film has emulsion on both sides of the film instead of emulsion on only one side because it requires less radiation to produce an image.
- Panoramic radiographs
- Also known as a panograph, panorex or a panelipse
- TemporoMandibular joint radiograph (TMJ)
- An exra-oral radiograph, show in profile the articulation of the mandibular condyle with the glenoid fossa of the temporal bone and the surrounding structure
- fast film
- requires less radiation, and the film responds more quickly because the silver halide crystals in the emulsion are larger.
- light-tight
- is often used to describe the darkroom, no light leaks can be present. When you are in the darkroom with the light turned off, no white light should be seen.
- processor housing
- covers all of the component parts.
- film speed
- determines how much exposure time is required to produce the image on the film.
- Green-sensitive
- This type of film is used with cassettes that have rare earth intensifying screens.
- Lateral Oblique jaw radiograph
- they are valuable for examining the body and ramus of the mandible
- Panoramic film 0
- should not be used to detect and evaluate caries or periodontal disease
- Dental X-Ray Film Processing
- Radiographs that are nondiagnostic because of poor processing techniques must be retaken, and the patient will be exposed to unnecessary radiation.
- disadvantage of Panoramic radiographs
- poor image detail and a varying degree of magnification and geometric distortion
- Dental X-Ray Film Processing
- In many practices, intraoral films are processed in an automatic processor; however, it is still necessary to know how to process the film manually.
- Safelighting
- There must be a safe distance between the light and the working area, and to work quickly to keep the exposure to the safelight as short as possible.
- Dental X-Ray Film Processing
- Processing is a series of steps that changes the latent image on the exposed film into a radiograph by producing a visible image on the film.
- Blue-sensitive
- This type of film is used with cassettes that have calcium tungstate intensifying screens.
- Dental X-Ray Film Processing
- Proper processing is just as important as the exposure technique in producing diagnostic-quality radiographs.
- The "F" speed
- is the newest and fastest film on the market today and will reduce radiation exposure to the patient by 20% to 60% compared to E-speed film and D-speed film
- Extraoral dental radiographs
- are beneficial when the client is unable to open their mouth or are unable to tolerate intraoral films