FILM  PROCESSING After the patient has been radiographed, the X-ray film is processed to produce the finished radiographs. There  are  five  basic  steps  involved  in  processing  X-ray film: developing, rinsing, fixing, washing, and drying. You can process the film manually, or use an automatic film processor. For the most part, manual processing is used  for  a  backup  method  for  the  automatic  film processor and will not be discussed. If your command has   manual   processing   capabilities,   refer   to   the manufacturer's   operating   instructions.   Because   our discussion  concerns  both  darkroom  procedures  and film processing, we will cover the darkroom first. DARKROOM   PROCEDURES The  darkroom  has  two  sources  of  illumination: white  light  and  safelight.  A  white  light  is  a  standard ceiling  light.  It  provides  regular  illumination  for mixing  solutions  and  cleaning  the  darkroom.  An unwrapped,  unprocessed  X-ray  film  must  never  be exposed to white light. Exposed   film   is   useless.   A   safelight,   which contains a 15 watt bulb with a special filter, is the only safe  source  of  illumination  in  the  darkroom  when processing  intraoral  and  panoramic  X-ray  film.  The safelight must be located no less than 4 feet from the work  surface  so  that  you  can  open  film  packets  and process  films  safely.  Limit  the  length  of  exposure  of undeveloped dental films to the safelight for no more than  2  minutes.  Films  left  out  exceeding  this  time might  get  a  fogged  image  (discussed  under  faulty radiographs). Occasionally,  films  are  ruined  because  of  light leakage. White light may leak through the filter on the safelight  or  it  may  leak  into  the  darkroom  from  an outside source. A simple test will enable you to detect leakage. To check for possible light leakage from an outside source, perform the test with all lights off, including the safelight. Take a packet of unexposed X-ray film, open the film packet, and remove the film. Lay the film on the workbench, and place a penny over it for a period of 5 minutes. Then, process the film using the procedures provided  later  in  this  chapter.  The  processed  film should show no image. If the outline of the penny can be seen, there is light leakage and you should inform your supervisor. You should perform this test at every location  in  the  darkroom  where  unwrapped  film  is being processed. SAFETY  PRECAUTIONS Because  of  the  alkaline  and  acid  nature  of  the developer   and   fixer   solutions,   minor   chemical irritation or burns can occur when they come in contact with  the  skin,  the  eyes,  and  the  mouth.  Use  caution when stirring or mixing solutions. Always wear rubber gloves  and  protective  eye  wear  or  a  protective  face shield  and  an  apron  when  working  around  these solutions.  If  the  solutions  come  in  contact  with  the skin, flush the area with large amounts of water. If the solutions  accidentally  splash  into  the  eyes  or  mouth, flush  with  large  amounts  of  water  and  immediately seek  medical  attention.  Fixer  solution  can  stain  and discolor clothing. AUTOMATIC  PROCESSING Automatic processing is the most commonly used method of processing dental radiographs in the Navy. The automatic film processor mechanically transports exposed  X-ray  film  through  the  developing,  fixing, washing,  and  drying  cycles.  Automatic  processing  is quicker  than  manual  processing,  and  it  produces finished  radiographs  of  uniform  quality.  A  variety  of automatic film processors are in use in the Navy and they can be generally classified as small or large. Large Automatic Film Processor The  large  automatic  processor  (fig.  1-44) processes  all  sizes  of  dental  radiographs  including intraoral,  occlusal,  panoramic,  and  8-inch  x  10-inch cephalometric films. This  processor  will  be  located  in  the  darkroom. The X-ray film must be inserted in the processor under safelight  conditions.  Large  automatic  processors  can be  equipped  with  daylight  loaders,  eliminating  the need for a darkroom. Operational Check Perform the operational check at the beginning of each  day  to  ensure  that  the  processor  is  in  good working order. It is a complex piece of equipment, so read   the   manufacturer's   operational   manual   very carefully.   Never   attempt   to   repair   the   components inside  the  processor.  There  are  a  variety  of  large automatic  processors  used  in  the  Navy  today.  The automatic   processor's   components,   procedures,   and 1-29