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FILM PROCESSING

FILM PROCESSING. DR SAMY I AL-AGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY. FILM PROCESSING. DEFINITION MECHANISM OF FORMATION OF LATENT IMAGE: Ag Br + X-ray photon---- Ag + Br- Ag+ ions form minute amount amount of ppt called Specks or spot of metallic Ag atoms

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FILM PROCESSING

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  1. FILM PROCESSING DR SAMY I AL-AGHA A.PROFESSOR OF RADIOLOGY ALAZHAR GAZA UNIVERCITY

  2. FILM PROCESSING • DEFINITION • MECHANISM OF FORMATION OF LATENT IMAGE: Ag Br + X-ray photon----Ag + Br- Ag+ ions form minute amount amount of ppt called Specks or spot of metallic Ag atoms Bromide ions -bromine gas

  3. LATENT IMAGE Latent image is formed of Ionized Ag halide+small amount of Ag+ spots • In Latent image there will be 1-Totally exposed crystals 2-Partially exposed crystals 3-Unexposed crystals

  4. FILM PROCESSING The major processing solutions are: 1-Developer 2-Fixer

  5. DEVELOPER • Phenidone (P) &Hydroquinone (Q) • 2AgBr + Hydroquinone-----2Ag+quinone+2HBr

  6. DEVELOPER • BUFFERING SYSTEM • Boric acid • NaOH

  7. DEVELOPER • Preservative • Na sulphite • To prevent oxidation

  8. DEVELOPER • Restrainer (Anti fog agent) • 1-Benzotriazole • 2-KBr

  9. DEVELOPER • Sequestrating agent • DTA Na salt • To prevent precipitation of Ca on film and developer tanks

  10. DEVELOPER • Hardening agent • Aldehyde &sulphate • To decrease swelling and softenning of emulsion

  11. DEVELOPER • Wetting agent • Detergent based derivatives • To produce uniform development of films

  12. DEVELOPER • Anti-Frothant

  13. DEVELOPER • Fungicidal • Recirculating water at high pressure 1.5 L/ min

  14. DEVELOPER • Starter solution • KBr +Acetic acid

  15. DEVELOPER DEVELOPER

  16. FIXER • Ammonium or Na Thiosulphate • p H 4.2-4.9 • Form permenant image

  17. FIXER • 1-Fixing agent • 2-Acid • 3-Buffer • 4-Preservative • 5-Hardener • 6-Solvent

  18. FIXER • FIXING AGENT • Na or Ammonium thiosulphate • * Clearing time 8-10sec in ammonium • 4-5 mins in Na • *Fixing time = 1.3xclearing time (Ammoni) • =2xclearing time(Na )

  19. FIXER • ACID &HARDENERS • 1-Acetic acid &Al Cl as hardener • 2-Sulphoric acid &Al sulphate as hardener

  20. FIXER • BUFFERS • Acetic Acid +Na or K sulphite

  21. FIXER • Hardeners ( In rapid film processing) • Al Cl3 • Al2(SO4)3

  22. FIXER FIXERS

  23. FILM PROCESSING • Totally exposed crystals--developer------black metallic Ag---Fixer-black • Partially exposed----developer&fixer--Gray • Unexposed crystals----developer&fixer--white.

  24. DARK ROOM • Site • Size • Lightening • Ventilation • Temp&humidity • Workable bench • Cleaninig

  25. LIGHTS IN DARK ROOM 1-Ordinary light 2-Safe light Specifications of the safe light • Wave length(orange or yellow) • Wattage of bulb(15watts) • Distance from light&workable bench(4feets) • Exposure time (4mints) • No of safe lights in average room(2)

  26. SAFE LIGHT COIN TEST

  27. EQUIPMENTS OF DARK ROOM 1-PROCESSING TANKS 2-DRYER 3-FILM RACKS(HANGERS) 4-STORAGE SPACE

  28. STEPS OF FILM PROCESSING 1-DEVELOPER(5mints) 2-RINSING WITH RUNNING WATER(10sec) 3-FIXATION (10 mints) 4-WASHING (20mints) 5-DRYING

  29. METHODS OF PROCESSING A-MANUAL(CONVENTIONAL) 1-Visual(inspection)method 2-Fixed time temp method B-SPEED PROCESSING 1-Automatic processing 2-Polaroid rate processing 3-Self contained processing solution 4-Ingectable films 5-Rapid processing chemicals

  30. MANUAL PROCESSING 1-VISUAL(INSPECTION) METHOD Advantage Disadvantage 2-FIXED TIME TEMP METHOD • Scientific standardized &reliable • The higher the temp-less the time of developing and vise versa

  31. RAPID PROCESSING METHODS 1-AUTOMATIC PROCESSING • It takes 1-5mints • Used for intra or extra oral films • No rinsing • Higher temp of processing solutions • Higher concentration of processing solutions • Regular replenshing of processing solutions

  32. AUTOMATIC PROCESSING ADVANTAGES • Time saving • Standardized results • No use of dark room during processing DISADVANTAGES • High cost • Regular mintanence&services • Processing specific NO of films at one time • High temp--more chemical fumes

  33. RAPID PROCESSING METHODS 2-POLAROID PROCESSING METHOD • Emulsion is coated on paper backing • Speed processing without need of dark room • Good for emergency • Needs high exposure time

  34. RAPID PROCESSING METHODS 3-SELF CONTAINED PROCESSING • 2Packets attached to the film packet • After film exposure we pull the 2 packetsone after the other to pour the developer and massage for 30sec then the fixer then the film is unrapped • Speedy&easy technique • Final image may be fogged due to non rinsing

  35. RAPID PROCESSING METHODS 4-INJECTABLE INTRA ORAL FILMS • Film packet have injectable site(tunnel) • No lead foil backing or black paper • After exposure-injection of developer for 30sec-fixer

  36. RAPID PROCESSING METHODS 5-RAPID PROCESSING CHEMICALS • High concentration of ready made solutions • Developing time is 10-30 sec • Less contrast • Film fogging • Rapid deterioration of solutions

  37. END

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