Dental Film and Processing Procedures Flashcards
Dental Film Holders
Types of intraoral film holders are available on market today.
- Disposable styrofam bite black: backinh plate and slot for film retention. Its advantage is that it is disposable and doesnot need to be sterilized.
-Snap A-RavC(formerly the Eezee-Grip): is a double eneded instruments that holds the film between serrated plastic grips that can be locked into place. it has advantage of being albe to be adjusted for patient with jaws too shallow to accommodate the full depth of film.
Endoray Device: is designed foe use in radiographs of eeth involving endonotic instruments in the cancal. If an endoray device is not available, it is not uncommon to have patients use finger or a hemostat to hold the film in place.
Uni-bite device: beam alignment device.
Introduction to dental film and processing
film-processing have a direct effect on the quility of a radiograph. The dental assistant must be knowledgeable about the types of dental film and film holding device and must also thought understand the processing procedure to produce high quality diagnostic dental radiographs.
Film: term for medium that x-ray rays will be exposed to. The film is in the packet; the film is placed in the bite block; and the film is exposed and processed. After the film has been processed, it becomes a radiography.
radiography: term for the film after the film has been exposed to x-rays and processed.
Dental X-ray Film
Film used radiography s similar to photographic film with some adaptation. A photographic image is produced on dental x-ray film when it is exposed to x-ray that have passed through teeth and adjacent tissues. The dental assistant must understandd the composition of x-ray film and latent image formation that result in increased patient exposure to x-rays.
Intraoral dental film is made of a clear semiflexible, cellulose actate film base that is coated on both sides with emulsion of sliver bromide, sliver halide, and sliver iodide that sensitive to radiation.
The emulsion layers on film allow an image to be produced with the use of less radiation.
Three types of r-ray film in dental radiography:
- Intraoral is the most common used.
- Extraoral
-Duplicating
Latent Image Formation
when the radiation interacts with the sliver halide crystals in film emulsion, the image on the film is produced. Te image, which is not visible before processing, is called latent image. fingerprint are anther type of latent image : image on film that is no visible until the film is processed. When you leave fingerprint on item after you have touched it. Even through you might not able to see them, fingerprint become visible when the items is treated.
produced. The image which is not visible before
Intraoral film
Intraoral film:is placed inside the mouth during x-ray exposure. The intraoral x-ray film has empulsion on both side of the film instead of just one because it require less radiation to produce an image. Light cannot pass through the packet but x-rays can.
Intraoral film packed typically are availbe in boxes of 25,100, or 150 film. The film can contain one film or two film packet.
Boxes of film are labeled with the following:
- Type of film
- film speed
- # of film per individual packet
- total number of films per individual packet
- Total # of films in the box
-expiration #.
Identification Dot: a small raised bump on one corner of film packet that help with the orientation of the radiograph.
Intraoral film packets
A thin back scattered lead foil sheet is positioned behind the film to shield from back-scatted radiation: secondary.
Intraoral film packets comes in five basic size:
- Child(size 0)
- narrow anterior (size 1)
- Adult size (size 2)
- preformed bite wing size 3-rarely
- occlusal size 4
Bite-wing x-ray usually are taken with size film and a bite tab or red XCP
extraoral film
extraoral film: placed ouside of the mouth during the x-ray exposure. extraoral film is used to examine large area of the head or jaws.
extraoral film is more common used specially practice. such as pediatric and oral surgery and orthodontic.
extraoral radiography uses a film screen system (combination with intensifying screens).
extraoral film use in dental radiography is avaliver in 5x7 inch and 8x20 inch size and is supplied in boxes of 50 or 100 films. Not supplied in film packets.
Cassette is a plastic or metal case used in extraoral radiography to hold the film and protect it from exposure to light.
The front side of the cassette must always face the patient during exposure.
panoramic film: view of the upper and lower jaw on a single radiograph. (pediatric dentists use panoramic film to see a developing a teeth becuase it difficult to have a child sit through a full mouth series of radiographs. It also exposes the child to less radiation than a full mouth series.
Cephalometric film shows the bony and soft tissue area of the facial profile. (orthodontist often use cephalometric film to view the relationship of the jaw to the skull).
Duplicating radiographs
Duplicating machine and special Duplicating film ( is used only ina darkroom setting and never exposed to x-rays.
Duplicating film are necessary to Duplicate machine produce white light exposes is performed in a darkroom under a safelight. the longer the Duplication film is exposed to light the lighter will become. This is the opposite of the x-ray which become taker when exposed to light. only light. duplicating film can never be exposed to x-rays.
Film speed
Film speed refers to the amount of radiation reqired to produce a radiograph of standard density.
density the darkness.
Film speed is determine by the following factors:
- Size of sliver halide crystals
- thickness of the emulsion
- presence of special radiosensitive dyes.
Facts: larger crystals increase film speed but reduce image resolution slightly/
F speed film, the newest and fastest film on the market today, reduce radiation exposure to the patients by 20-60% compared with E speed and D.
E speed and D: commonly used by cost conscious dentists because the relative decrease in radiation exposure from F speed is small when only a few exposure are involved.
Dental X ray film processing
Processing a series of steps that changes the latent image on the exposed film into a radiograph by producing a visible image on the film.
Radiographs that are nondiagnostic because of poor processing techniques must be retake, exposing the patient to necessary radiation.
Intraoral film is processed in an automatic process. However, it is still necessary to know to process the film manually:
- to identify and correct errors is processing
- to develop a film more quickly as with endodontics.
Steps to dental radiograph processing
- step1: development
-step2: rinsing
-step3: fixation
-step4: wa: washing
-step5: drying
Flim processing solutions
Flim processing solutions are available in following forms:
- Powder
- ready to use liquid
- liquid concentrate-most commonly used solution. powder and concentrate require mixing that most practice choose not to take the time to do.
Darkroom requirements
Darkroom mist be clean and organized at all times, properly developing x-ray film requires a light darkroom. The darkroom should be equipped with items listed here
- Gloved, disinfectant spray, and paper towels
- container, labeled with biohazard label
- Recycling container for lead foil pieces
- processing tanks for the developer and fixer solution, and a circulating water bath
- Running water with mixing valves to adjust the temperature
- Both safelight and source of white normal light
- Accurate timer
- Accurate floating thermomeer
- stirring rods or paddles to mix the chemicals and equalize the temperature of solutions
- soft storage space for chemicals
- film hangers
- film dryer rack and film dryer.
Processing tank
manual processing is a method that is used to develop, rinse, fix and wash dental x-ray film without an automate machine.
Processing tank a piece of equipment used in the manual processing of film. it is divided into compartment to hold the developer solution, water bath and fixer solution.
The solution should be chanaged every three to four weeks.
Automatic film processing
Never open the automatic processor with the overhead light when film is being processed. If a film gets stuck. If a film gets stuck, open the automatic processor with the safelight on and dry to locate the film.
Automatic film processing is fast and simple method used too process dental x-ray film. It requies only 4-6 min for development, fixing, washing and drying of film.
Automatic film advantages:
- less processing time is required. 4-6 min
- time and temperature and automatically controlled
- less equipment is used.
- less space is required.
