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Image receptors & accessories/certified fixed orthodontic courses by Indian dental academy
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Image receptors & accessories/certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different …

The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.


Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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  • 1. OMR, CODS, DVG INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. OMR, CODS, DVG Image Receptors: Initially glass plates were used By 1900: celluloid base film 1913: Moisture proof dental packet 1919: Kodak ‘Regular’ film 1924: Kodak ‘Radiatized’ film 1940: Kodak ‘Ultraspeed’ film 1952: Selenium plates in Xeroradiography 1981: Kodak ‘Ektaspeed’ film 1989: CCDs developed for dental radiography 1994: Kodak ‘Ektaspeed Plus’ film www.indiandentalacademy.com
  • 3. IMAGE RECEPTORS OMR, CODS, DVG Types: 1. X-ray Films 2. Fluorescent Screens 3. Selenium Plates 4. CCDs Types: 1. X-ray Films 2. Fluorescent Screens 3. Selenium Plates 4. CCDs www.indiandentalacademy.com
  • 4. IMAGE RECEPTORS • Direct exposure films ( also called as no n-scre e n films ) are used in intra- oral radiography • Indirect exposure films ( also called as scre e n films ) are used in extra- oral radiography in combination with intensifying screens OMR, CODS, DVG X-ray Films: www.indiandentalacademy.com
  • 5. IMAGE RECEPTORS Composition of an X-ray Film OMR, CODS, DVG Supercoat Emulsion Base www.indiandentalacademy.com
  • 6. IMAGE RECEPTORS Composition of an X-ray Film OMR, CODS, DVG • Supercoat: a thin layer of polyester or gelatin covers both surfaces of the film to protect the emulsion from scratching • Supercoat: a thin layer of polyester or gelatin covers both surfaces of the film to protect the emulsion from scratching • Emulsion: coated on both sides of the base ~ made up of gelatin matrix in which silver halide ( mainly AgBr2 ) crystals are suspended ~ crystals are 1 / 0.7 micrometer in thickness • Emulsion: coated on both sides of the base ~ made up of gelatin matrix in which silver halide ( mainly AgBr2 ) crystals are suspended ~ crystals are 1 / 0.7 micrometer in thickness • Base: ~ made up of polyethylene terephthalate ( polyester ) ~ 0.2 mm in thickness ~ translucent, chemically inert ~ supports emulsion • Base: ~ made up of polyethylene terephthalate ( polyester ) ~ 0.2 mm in thickness ~ translucent, chemically inert ~ supports emulsion www.indiandentalacademy.com
  • 7. IMAGE RECEPTORS Uses & Dimensions of Intra-oral X-ray Films OMR, CODS, DVG • Periapical Projection: to record teeth and alveolar bone 3 sizes ~ ‘0’ : 22 x 35 mm ( for children ) ~ ‘1’ : 24 x 40 mm ( for anterior teeth ) ~ ‘2’ : 32 x 41 mm ( for adults ) • Bitewing Projection: to record crown portion of maxillary and mandibular teeth in one image ~ Size ‘0’ and ‘1’ for children ~ Size ‘2’ for adults ~ Size ‘3’ ( 27 x 54 mm ) • Occlusal Projection: to record larger areas of maxilla or mandible ~ Size ‘4’ ( 57 x 76 mm )www.indiandentalacademy.com
  • 8. IMAGE RECEPTORS Uses & Dimensions of Intra-oral X-ray Films OMR, CODS, DVG Size ‘4’ (57 x 76 mm) Size ‘0’ (22 x 35 mm) Size ‘2’ (32 x 41 mm) www.indiandentalacademy.com
  • 9. IMAGE RECEPTORS Contents of an X-ray Film Packet OMR, CODS, DVG www.indiandentalacademy.com
  • 10. IMAGE RECEPTORS Contents of an X-ray Film Packet OMR, CODS, DVG † Plastic cover † Black paper † Lead foil † Direct exposure film Protects the film from moisture and light Protects the film exposure to light 1. Protects tissues on the other side of the film from radiation 2. Prevents backscatter radiation from reaching the film 3. Gives sufficient stiffness to the film packet Captures the image pattern and forms a latent image www.indiandentalacademy.com
  • 11. IMAGE RECEPTORS • Direct exposure films ( also called as no n-scre e n films ) are used in intra- oral radiography • Indirect exposure films ( also called as scre e n films ) are used in extra- oral radiography in combination with intensifying screens OMR, CODS, DVG X-ray Films: ¤ These films are similar in their composition to the non-screen films with the exception that certain impurities are added to make the emulsion more sensitive to light. ¤ The latent image is formed by the light emitted from the intensifying screens. www.indiandentalacademy.com
  • 12. ACCESSORIES OMR, CODS, DVG 1. Intensifying screens 2. Film holders, cassettes & stands 3. Grids 1. Intensifying screens 2. Film holders, cassettes & stands 3. Grids www.indiandentalacademy.com
  • 13. ACCESSORIES OMR, CODS, DVG Intensifying screens - Composition Protective layer Phosphor layer Reflecting layer Base ~ made up of polyester ~ about 0.25 mm thick ~ provides mechanical support to the screen ~ made up of polyester ~ about 0.25 mm thick ~ provides mechanical support to the screen ~ made up of titanium dioxide ~ about 0.025 mm thick ~ reflects the light from the phosphor layer back to the film ~ made up of titanium dioxide ~ about 0.025 mm thick ~ reflects the light from the phosphor layer back to the film ~ made up of phosphor crystals suspended in plastic ~ phosphor materials used are : calcium tungstate or rare earth elements like # terbium activated gadolinium oxysulfide # thulium activated lanthanum oxybromide ~ emits light when exposed to x-radiation ~ exposure to an x-ray photon results in emission of several light photons ~ help in reducing radiation dose in extra- oral radiography ~ made up of phosphor crystals suspended in plastic ~ phosphor materials used are : calcium tungstate or rare earth elements like # terbium activated gadolinium oxysulfide # thulium activated lanthanum oxybromide ~ emits light when exposed to x-radiation ~ exposure to an x-ray photon results in emission of several light photons ~ help in reducing radiation dose in extra- oral radiography ~ made up of polyester ~ about 0.8 microns thick ~ protects the phosphor layer and provides a surface that may be cleaned ~ made up of polyester ~ about 0.8 microns thick ~ protects the phosphor layer and provides a surface that may be cleaned www.indiandentalacademy.com
  • 14. ACCESSORIES OMR, CODS, DVG Intensifying screens - Functioning www.indiandentalacademy.com
  • 15. ACCESSORIES OMR, CODS, DVG Intensifying screens - Functioning The x-ray film, therefore, needs to kept very close to the intensifying screen. In fact, it is sandwiched between a pair of intensifying screens inside a metallic cassette. Magnification and Unsharpness of Image www.indiandentalacademy.com
  • 16. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Film Holders hold the film in patient’s mouth, and maintain its position during exposure. They may also aid in alignment of x-ray beam with the x-ray film. XCP (extension cone paralleling) Instrumentswww.indiandentalacademy.com
  • 17. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Film Holders : www.indiandentalacademy.com
  • 18. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Film Holders hold the film in patient’s mouth, and maintain its position during exposure. They may also aid in alignment of x-ray beam with the x-ray film. Snap-A-Ray Instrumentwww.indiandentalacademy.com
  • 19. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Film Holders hold the film in patient’s mouth, and maintain its position during exposure. They may also aid in alignment of x-ray beam with the x-ray film. Artery forceps or needle holder www.indiandentalacademy.com
  • 20. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Cassettes carry a non-screen film between a pair of intensifying screens. They protect the film from light and moisture, and also maintain a tight contact between the film and the intensifying screens. www.indiandentalacademy.com
  • 21. ACCESSORIES OMR, CODS, DVG Film Holders, Cassettes & Stands Cassette stands are used in extra-oral radiography for holding and maintaining the cassette in correct position with respect to the patient. www.indiandentalacademy.com
  • 22. ACCESSORIES OMR, CODS, DVG Grids A grid is composed of alternate strips of a radiopaque material (usually lead) and strips of a radiolucent material (usually plastic). Purpose of grid is to prevent the secondary radiation coming from the tissues from reaching the film, thus improving the image quality. Grid Film U S E F U L R A D I A T I O N Secondar y radiation Secondar y radiation www.indiandentalacademy.com
  • 23. ACCESSORIES OMR, CODS, DVG Grids Types of grids: • stationary and mobile (Bucky, Potter-Bucky diaphragm) • parallel, focussed Grid ratio: ratio of grid thickness to the width of radiolucent spacer. Higher the grid ratio better is the image quality. Generally a grid ratio of 8-10 is satisfactory. Use of grids requires doubling of exposure. Hence, grids should be used only when sufficient improvement in image quality is expected. As large amounts of secondary radiation is produced by the maxillo-facial structures grids are useful in extra- oral radiography. In intra-oral radiography, grids can neither be used nor is there a need to use them.www.indiandentalacademy.com
  • 24. IMAGE RECEPTORS & ACCESSORIES OMR, CODS, DVG 1. Intensifying screens 2. Film holders, cassettes & stands 3. Grids 1. Intensifying screens 2. Film holders, cassettes & stands 3. Grids Types: 1. X-ray Films 2. Fluorescent Screens 3. Selenium Plates 4. CCDs Types: 1. X-ray Films 2. Fluorescent Screens 3. Selenium Plates 4. CCDs www.indiandentalacademy.com
  • 25. IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG A CCD is made of an array of pho to dio de s (devices that conduct electricity when light or x-rays strike them) on top of a semiconductor. ‘CCD’ is a sensitive electronic device that stores packets of information as electric charge. www.indiandentalacademy.com
  • 26. Each element, called a ‘pixel’, is 20-60 microns in size. (A human hairis about 60 microns in diameter!) IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG www.indiandentalacademy.com
  • 27. serial output register serial output register output amplifier output amplifier Computer hardware & software Computer hardware & software Display Storage Printer Display Storage Printer IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG www.indiandentalacademy.com
  • 28. IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG www.indiandentalacademy.com
  • 29. IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG www.indiandentalacademy.com
  • 30. IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG  High image quality at considerably less radiation dose as compared to film radiography.  Image is dynamic and can be altered digitally.  No processing required; therefore environment friendly.  Image is available instantly.  No processing errors.  No loss of image over a period of time.  Image duplication is very easy.  Telemedicine. Advantages : www.indiandentalacademy.com
  • 31. IMAGE RECEPTORS Charge-Coupled Device ( CCD ) OMR, CODS, DVG Limitations:  Very high initial cost.  Sensor is bulkier compared to an x-ray film making it difficult to place in some parts of the mouth and in children. www.indiandentalacademy.com
  • 32. DIRECTING THE X-RAY BEAM TO THE OBJECT INTERACTION OF X-RAYS WITH MATTER DIFFERENTIAL ABSORPTION OF THE X-RAY BEAM EMERGENCE OF AN INVISIBLE IMAGE PATTERN CAPTURE OF THE INVISIBLE IMAGE PATTERN ON AN IMAGE RECEPTOR ‘Latent Image’ Processing Latent image is formed when tiny specks of metallic silver are deposited in those silver bromide crystals that are exposed to radiation. This image is invisible. www.indiandentalacademy.com
  • 33. www.indiandentalacademy.com Thank you For more details please visit www.indiandentalacademy.com