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Film Processing -Series of steps -Converts the invisible image into a permanent visible image -Manually or automatically Overview of Film Processing -Latent image -Silver halide crystals -Developer -Rinsing -Fixer -Washing -Drying Developing reduces silver halide crystals into.. black metallic silver. Rinsing removes as much as possible.. alkaline developer. Fixer removes the undeveloped silver halide crystals from.. the film emulsion. Washing removes all.. remaining chemicals. Radiographic images are made up of.. microscopic grains of black metallic silver. Forms of processing solutions -Powder -Ready to use -Liquid concentrate Purpose of the developer Converts crystals onto film Developing agents of the developer -Hydroquinone -Elon Hydroquinone -Slowly build up black tones onto film. -The higher the temp. the faster it works. Elon -Brings out gray tones -Works very fast, higher temp. the faster it works Preservative of the Developer Sodium Sulfite Sodium Sulfite -Slows down oxidation rate -Preserves chemicals Activator of the Developer Sodium Carbonate Sodium Carbonate Soften/swell gelatin on film, which then exposes more crystals Restrainer of the Developer Potassium Bromide Potassium Bromide Restrain developing agents from unexposed crystals. Fixer is.. acidic. Purpose of the fixer -Stops further development of film -Removes undeveloped silver halide crystals -Hardens emulsion Fixing agent of the Fixer Ammonium thiosulfate or sodium thiosulfate Fixing agent (Clearing agent) Remove all unexposed crystals from film. Preservative of the Fixer Sodium Sulfite Preservative Slows down oxidation rate of fixer. Hardening agent of the fixer Potassium alum Hardening agent Hardens gelatin/emulsion Acidifier of the fixer Acetic acid Acidifier Stops further development Hardening Agents Helps prevent rollers from scratching film Replenisher Helps compensate for loss of chemicals Purpose of the darkroom Provide dark area for film to be developed Requirements of the darkroom -Safelight -Well ventilated -Adequate storage Lighting in darkroom -Light tight -White ceiling light -Safelight (safe bulbs) -Viewbox -In-Use light The safelight must be at the minimum ____ from counter. 4 ft. Useful life of chemicals -Original quality of solution -Freshness of the solution (exp. date) -Number of films that are processed -Contamination of chemicals (mixing fire with developer) Processing Chemical Maintenance -Useful life of chemicals -Cleaning -Changing solutions Disposal of Radiographic Wastes -Biohazard materials -Fixer waste (doesn't go through city water) -Recycling lead foil Manual Processing Procedures (dipping) Method to process films in a series of steps performed by hand. Advantages of manual processing -Reliable -Clinician has more control Disadvantage of manual processing -Time Processing Tank Holds chemicals in it Thermometer Temperature of chemicals Timer Must know how long they're in Stirring paddles Stir solutions Film hangers Clip film to, hang film into solution Drip Pans Catch water Drying racks Used to air dry Oxidation Decreases volume of developer & fixer. Keep tanks.. covered. Inserts should be.. scrubbed. Never use.. cleansing powders. (Comet) All tank parts should be.. wiped clean. Preparations of Manual Processing -Check levels of all solutions -Stir the developer & fixer -Determine the temperature of solution -Reticulation (cracking of the film, going from really hot to cold) -Select the proper film hanger (making film goes all the way into solution) Ideal temperature for manual processing 68° for 5 minutes in developer Procedure for Manual Processing -Developing -Rinsing -Fixing -Washing -Drying Developing -5 minutes -Shake film up & down to get rid of bubbles Rinsing -into water -about 20 seconds Fixing -after 2-3 minutes, you can turn on light -minimum of time: 10 minutes Washing 20 minutes Drying Before you mount Automatic Processing Advantages -Less time -Time/temperature is controlled Day light loader machine With mini darkroom on top of machine Compartments of Automatic Processing Complete cycle 5 minutes Chemistry of Automatic Processing -Super saturated -Can't use same chemicals as manual Maintenance of Automatic Processing Cleaned weekly Disadvantages of Automatic Processing -Expensive -Jamming (eats film) -Rollers can leave marks Example of Rapid Processing Chairside darkroom Chairside darkroom 30 seconds/ a piece of film Practices that use rapid processing Endodontic & oral surgery practice Chemistry of rapid processing Higher temperature chemistry Results of rapid processing -Not intended to replace regular types of film -Quick dip