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145 Cards in this Set
- Front
- Back
Define Radiation |
form of energy carried by waves or a stream of particles |
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Define X-radiation |
a high energy radiation produced by the collision of a beam of electrons with a metal target in an x-ray tube. |
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Define Radiology |
The science or study of radiations as used in medicine |
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Define X-ray |
A beam of energy that has the power to penetrate substances and record image shadows on photographic film |
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Define Radiograph |
A picture on film produced by the passage of x-rays through an object |
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Define Radiography |
The art or science of making radiographs by the exposure of film to x-rays |
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Define Dental Radiographer |
Person who exposes, positions, and processes dental x-ray film |
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Who discovered radiology, and when? |
Wilhelm Roentgen in 1895 |
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How did Wilhelm come across discovering radiology? |
He was experimenting with cathode rays. He noticed rays that exited the tube and went further than the cathode rays and caused screens to glow (fluoresce) when contacted or striked |
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Would the rays go through cardboard? |
Yes |
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Who took the first dental radiograph in 1896? |
Otto Walkhoff |
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Who took the first dental radiograph using a skull? |
W.J. Morton |
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Who developed the hot cathode x-ray tube? |
William D. Coolidge |
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Who is commonly referred to as the "father of modern dental radiography"?* |
F. Gordon Fitzgerald (In 1947 he revived the interest in the paralleling technique with the intro of the long-cone paralleling technique) |
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Before 1974, were x-ray machines regulated?* |
No |
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What are the 3 component parts of intraoral machines? |
1) Tubehead 2) Extension arm 3) Control panel |
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Define film holder |
Used to hold and align the film inside the mouth (eliminating the need for the patient to stabilize the film) |
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Define beam alignment device |
An instrument used to help the radiographer position the PID (end of the tubehead) in relation to the tooth and film |
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What is the primary benefit to the patient?* |
Detect disease, minimize and prevent problems |
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T/F: The benefit of disease detection does not outweigh the risk of small doses of x-radiation |
False |
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T/F: Patient and operator protection must be primary concerns of the dental radiographer |
True |
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T/F: Through the use of dental radiographs, the dental professional can detect diseases, lesions, and conditions of the jaws that cannot be identified clinically |
True |
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Name the 3 types of intraoral radiographic exams |
1) Periapical exam 2) Interproximal exam (Bite-wing) 3) Occlusal exam |
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What is the purpose of periapical exams? |
To examine the entire tooth and supporting bone |
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What is the purpose of interproximal (bite-wing) exams? |
To examine the crowns of both arches on a single film; used to examine adjacent tooth surfaces and crestal bone |
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What is the purpose of occlusal exams? |
Used to examine large areas of the maxilla or mandible |
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What film type is used for periapical x-rays? |
Size 0, 1, 2 |
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What film type is used for interproximal x-rays? |
Bite-wing film (winged or tabbed) |
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What film type is used for occlusal x-rays? |
Size 4 for adults Size 2 for children |
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What is another name for Complete Mouth Radiographic Series (CMRS)? |
FMX (full mouth series)**most common FMS (full mouth series) CS (complete series) |
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T/F: An FMX includes both dentulous and edentulous areas |
True |
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How many films are used for a complete mouth series? |
14 to 18 films |
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What are some examples of extraoral x-rays? |
1) Panoramic 2) Lateral jaw 3) Lateral cephalometric 4) Posteroanterior 5) Waters 6) Submentovertex 7) Reverse Towne 8) Transcranial 9) Tomographic projections |
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What should we remember when prescribing radiographs?* |
Dental radiographs are taken based on the individual need of the patient. They are ultimately decided by the dentist* |
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What is the difference between intraoral and extraoral examinations? |
The intraoral examination is a radiographic inspection of teeth and intraoral structures.
The extraoral examination is a radiographic inspection of large areas of the skull or jaws. |
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Dental x-ray films serve as: |
1) A recording medium 2) An image receptor |
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What are the 4 basic components of the film base? |
1) Supercoat 2) Emulsion 3) Adhesive 4) Base |
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What is the supercoat's job? |
It serves as a protective layer |
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What color is the film base? |
Transparent (slight blue tint) |
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Define adhesive layer |
Attaches emulsion to the film base |
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What is found on both sides of the film?* |
Film emulsion |
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What is the film emulsion made up of?* |
Homogenous mixture of gelatin and silver halide crystals |
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What is the function of the protective layer? |
It protects the emulsion from damage. It is also a thin and transparent coating. |
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What kind of crystals absorb x-rays during x-ray exposure?* |
Silver halide crystals |
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What will make the crystals turn black? |
Air and soft tissues |
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Stored energy forms a pattern or image within the emulsion. What is this "invisible image" called? |
Latent image |
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What happens at the latent image center? |
This is where neutral silver atoms aggregate and produce a latent image. The atoms are drawn to the sensitivity speck of the crystal b/c of the high number of electrons present at these specks. |
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T/F: When the film is processed, the latent image becomes visible |
True
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T/F: When the film is processed, the silver will produce a dark area on the film |
True |
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Do sensitivity specks attract free electrons? |
Yes |
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What is a lead foil sheet? (Inside the intraoral film packet) |
A single piece of lead foil located behind the film. It protects the film from back-scattered radiation that can destroy the image. |
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T/F: An embossed pattern is placed on the foil sheet and is visible if the film is placed backwards in the patients mouth |
True |
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What does the tube side of a film packet look like?* |
Tube side: solid white and has the raised bump in one corner. This faces the tubehead and teeth. (Bite-wing tabs are placed on this side of the film packet). |
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What does the label side of the film packet look like?* |
Label side: has a flap used to open the film packet. This side is color coded (depending on film speed, whether it contains 1 or 2 films, etc.) This side faces the tongue when placed in the mouth. |
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Intraoral film speed (sensitivity)* |
The faster the film speed the more sensitive to radiation the film is and the less amount of radiation required to produce an image. |
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T/F: Film speed is categorized alphabetically from slowest to fastest* |
True |
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What is the fastest film speed? |
F speed |
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T/F: E speed has been discontinued |
True |
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Screened films* |
Uses intensifying screens on both sides of film |
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Are non-screen films used in dentistry? |
No |
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Are non-screen films exposed directly to x-rays? |
Yes |
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The American Academy of Oral and Maxillofacial recommends what type of film speed?* |
F-speed |
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Film storage and protection protocol is to keep x-rays in a cool and dry place. What temperature and humidity?* |
50-70 degrees 30-50% humidity |
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Film exposure errors:
*Unexposed film |
Appearance: clear Cause: failure to turn on the machine, electrical failure, operator error Correction: listen for the audible exposure sound and make sure machine is turned on |
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Film exposure errors:
*Film exposed to light |
Appearance: black Correction: do not unwrap it in a room with white light, check for light leaks |
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Film exposure errors:
*Overexposed film |
Appearance: dark film Cause: excessive exposure time, kVp, mA, or a combination of these factors Correction: check the exposure settings before exposing patient to radiation |
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Film exposure errors:
*Underexposed film |
Appearance: light film Cause: inadequate exposure time, kVp, mA or a combination of these factors Correction: check the exposure settings |
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Technique errors: (Periapical films)
*Film placement problems |
a) Film does not extend 1/8 inch beyond the incisal or occlusal surface b) Apices do not appear on the film c) Dropped film corner |
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Technique errors: (Periapical films)
*Angulation problems |
a) Horizontal angulation -Overlapping of contacts -Direct the central ray through the contacts b) Vertical angulation -Foreshortened images: vertical ang. too excessive/too steep -Elongated images: vertical ang. was insufficient/too flat |
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What can happen if you have a horizontal angulation problem? |
Overlapping of contacts appear
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What can happen if you have a vertical angulation problem? |
1) Foreshortened images 2) Elongated images |
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Describe foreshortened images |
Vertical angulation was too excessive/too steep |
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Describe elongated images |
Vertical angulation was insufficient/too flat |
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*Name a PID alignment problem
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Cone cut |
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Describe cone cut |
Appears as a clear, unexposed area either circular or rectangular |
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*What should you do to avoid cone-cutting? |
Make certain the central ray is directed to the center of the film |
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Technique errors: (Bite-wing films)
*Film placement problems |
a) Occlusal plane should be positioned horizontally b) Make certain the film is positioned to cover the teeth it is supposed to cover -Premolars -Molars
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Technique errors: (Bite-wing films)
*Angulation problems |
a) Horizontal angulation b) Vertical angulation: the 10+ degree vertical ang. compensates for the slight tilt of the max. teeth and the slight lingual bend of the upper half of the film caused by the hard palate |
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Miscellaneous technique errors:
*Film bending |
Appearance: images on the radiograph appear stretched or distorted Cause: either the curvature of the hard palate or excessive pressure by the patient when holding the film in place Correction: instruct pt to use a gentle stabilizing technique. Use cotton rolls if using the paralleling technique. Use the bisecting technique to compensate for curvature of the palate |
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Miscellaneous technique errors:
*Film creasing |
Appearance: radiolucent (black) line on the film Correction: do not bend the film excessively |
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Miscellaneous technique errors:
*Phalangioma |
Appearance: the patient's finger appears on the film Cause: patient finger was in between the teeth and the film instead of being behind the film
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Miscellaneous technique errors:
*Double exposure |
Appearance: double image on one film Correction: always separate exposed and unexposed films |
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Miscellaneous technique errors:
*Movement
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Appearance: blurred images Cause: patient movement
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Why is double exposure a serious error? |
Because it results in two retakes |
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T/F: Blurry images are caused by the operator |
False |
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*In order to produce high quality diagnostic dental radiographs, dental x-ray film must be... |
Properly exposed and processed |
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Film processing fundamentals |
*During processing, a chemical reaction occurs, and the halide portion of the exposed, energized silver halide crystal is removed |
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*Selective reduction |
Occurs in that only the energized, exposed silver halide crystals are reduced into a black metallic silver while the unexposed crystals are removed from the film |
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Radiolucent film appears light or dark? |
Dark
Lucent=Lucifer=Dark |
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Radiopaque film appears light or dark? |
Light |
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*What are the 5 film processing steps? |
1) Development 2) Rinsing 3) Fixation 4) Washing 5) Drying |
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What happens during the development step? |
The emulsion is softened and the silver halide crystal is reduced to black metallic silver (dark) |
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What happens during the rinsing step? |
It is necessary to remove the developer from the film and stop the development process |
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What happens during the fixation step? |
The film is immersed in a fixer agent which removes the unexposed unenergized silver halide crystals from the film emulsion; the fixer solution also hardens the film emulsion during this process |
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What happens during the washing step? |
Designed to thoroughly remove all excess chemicals from the emulsion |
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Why is the drying step important? |
Films must be completely dried before they can be handled |
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*Film processing solutions are available in what forms? |
1) powder 2) ready-to-use liquid 3) liquid concentration |
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*How often should film processing solutions be replenished? |
Must be replenished daily and changed every 3 to 4 weeks based on "normal use" |
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*What are the 4 basic ingredients of developer solution? |
1) Developing agent 2) Preservative 3) Accelerator 4) Restrainer |
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What does the developing agent do? |
Reduces the exposed silver halide crystals chemically to black metallic silver.
Composed of 2 chemicals: Hydoquinone & Elon |
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What does the preservative do? |
Used to prevent the developer solution from oxidizing (air) |
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What does the accelerator do? |
Activates the developing agents, provides the alkaline environment needed for the developing solutions to be activated, and it softens the emulsion so the developing agents can reach the crystals more effectively |
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What does the restrainer do? |
Controls the developer (prevents it from developing unexposed silver halide crystals) |
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*What are the 4 basic ingredients of fixer solution? |
1) Fixing agent 2) Preservative 3) Hardening agent 4) Acidifier |
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What is the purpose of the fixing agent?
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To remove or clear all unexposed and undeveloped silver halide crystals, and distinguishes the black images
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What are black images? |
Images that have developer on them |
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What is the purpose of the preservative in the fixer solution? |
Prevents the chemicals from deteriorating |
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What is the purpose of the hardening agent? |
Hardens and shrinks the gelatin in the film emulsion |
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What is the purpose of the acidifier? |
Used to neutralize the alkaline developer and create the acidic environment needed by the fixing agent. Un-neutralized alkali may cause the unexposed crystals to continue to develop in the fixer |
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What is one thing the developer solution and fixer solution have in common? |
They both have a preservative |
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*Darkroom requirements |
1) Volume of radiographs processed 2) Number of persons using the room 3) Type of processing equipment used (tanks or auto processor) 4) Space required for duplication and films and storage
...doesn't make much sense, sorry |
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*Processing tank |
An essential piece of equipment required for manual processing |
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What temperature should the master tank of the processing tank be? |
Optimum of 68 F |
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T/F: The processing tank should have a light-tight lid that is used to cover the solutions at all times |
True |
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*What are the 4 equipment accessories of manual film processing? |
1) Thermometer 2) Timer 3) Film hangers 4) Misc. equipment (sitrring rod, apron) |
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*What are the 3 care and maintenance procedures for manual film processing? |
1) Processing solutions 2) Processing tank 3) Miscellaneous equipment |
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*What are the 4 component parts we need to know on an automatic film processor? |
1) Processor housing 2) Film feed slot 3) Roller film transporter 4) Film recovery slot |
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What component part encases all of the component parts? |
Processor housing |
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What component part has an opening on the outside that is used to insert unwrapped films? |
Film feed slot |
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Roller film transporter |
System of rollers used to move the film through the developer, fixer, water and drying compartments |
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Film recovery slot |
Opening on the outside of the processor where film is retrieved |
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*Automatic processor |
An extraoral-size cleaning film used to clean the rollers. Should be run through the processor at the beginning of each day. |
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* Processing solutions |
1) Solution levels should be checked at the beginning of each day 2) Solutions should be replaced every 2 to 6 weeks |
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*What are the 2 equipment requirements for film duplication? |
1) Film duplicator 2) Duplicating film |
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Film duplicator |
Light source that provides a diffused light source that evenly exposes the special duplicating film |
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Duplicating film |
A type of photographic film that is used to make an identical copy of an intraoral or extraoral radiograph |
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T/F: Duplicating films are never exposed to x-rays and are not used on the patient |
True |
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*Step by step procedures of film duplication |
Should be done in a light-tight darkroom |
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*What are the 3 things that can happen to your film relating to time and temperature? |
1) Underdeveloped film 2) Overdeveloped film 3) Reticulation of Emulsion |
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*Underdeveloped film |
Causes: inadequate development time, inaccurate timer or thermometer, low developer temperature, depleted or contaminated developer solution Prevention: check the time and temp of the developer cycle, increase film time in the developer as needed, replace faulty and inaccurate thermometers and times, replace developer |
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*Overdeveloped film |
Causes: excess development time, inaccurate timer or thermometer, high developer temp, concentrated developer solution Prevention: check the temp and time the film should remain in the developer solution, decrease the time the film remains in the developer as needed, replace inaccurate thermometers and timers, replace developer |
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*Reticulation of Emulsion |
Causes: when a film is subjected to a sudden temperature change between the developer and water bath Prevention: check the temp of the processing solutions and water bath |
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*What are the 3 chemical contaminations that can happen? |
1) Developer spots 2) Fixer spots 3) Yellow-brown stains |
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*Developer spots |
Appearance: dark spots on the film Causes: when developer solution comes in contact with the film before processing Prevention: use a clean work area in the darkroom |
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*Fixer spots |
Appearance: white spots appear on the film Causes: fixer solution comes in contact with the film before processing Prevention: ensure a clean work area |
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*Yellow-Brown stains |
Causes: use of exhausted developer or fixer, insufficient fixation time, or insufficient rinsing Prevention: replace depleted developer and fixer solutions, make certain fixation time and rinsing time are adequate, ensure rinsing time in circulating water is at least 20 minutes |
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*What are the 4 film handling processing problems we need to know? |
1) Developer cut-off 2) Fixer cut-off 3) Overlapped films 4) Air bubbles |
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*Developer cut-off |
Appearance: straight white border on the film Causes: low levels of developer Prevention: check developer lever before processing films |
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*Fixer cut-off |
Appearance: straight black border on the film Causes: low level of fixer solution Prevention: check the fixer level before processing films |
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*Overlapped films |
Appearance: white or dark areas on films Causes: 2 films come into contact during processing Prevention: be careful! |
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*Air bubbles |
Appearance: white spots on the film Causes: when air is trapped on the film surface after the film is placed in the processing solutions and prevent the chemicals from interacting with the emulsion in that area Prevention: gently agitate and stir film racks after placing them in the processing solution |
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*What 3 things should we be concerned about with lighting and films? |
1) Light leak 2) Fogged film 3) Completely clear film |
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*Light leak |
Appearance: exposed area appears black Causes: accidental exposure of the film to white light, torn or defective film packets Prevention: examine film packets for minute tears of defects before use, never unwrap films in the presence of white light |
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*Fogged film |
Appearance: film appears gray and lacks image detail or contrast Causes: improper safelighting and light leaks in the darkroom, improper film storage, outdated films, contaminated processing solutions, high developer temperature Prevention: check the filter and bulb of the safelight, minimize film exposure to the safelight and check the darkroom for light leaks, always check expiration date, store films in a cool, dry and protected area, avoid contamination of processing solutions by replacing tank covers after each use, check developer temperature before processing films |
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*Completely clear film |
Appearance: clear film Causes: never exposed, left the film in the fixer too long |