What is film processing?
Steps that produce a visible image on a dental radiograph
What are film processing fundamentals? (simple step by step)
What is reduction?
A chemical reaction where the halide portion of the exposed, energized silver halide crystal is removed. Reaction results in precipitated black metallic silver
What is selective reduction?
Reduction of energized, exposed silver halide crystals into black metallic silver while the unenergized, unexposed silver halide crystals are removed from the film
Describe the process of a film going from latent image to visible image
What ‘colours’ are shown on the visible image?
Black, white and grey areas
What does the amount of black areas in the visible image depend on?
the amount of black metallic silver depending on the structures being x-rayed (radiolucent vs radiopaque)
What is radiolucency? Radiopaque?
Radiolucent means readily permits passage of x-rays and will result in a dark area. Radiopaque means resists the passage of the x-ray beam and will appear white
What are the 5 steps for film processing?
Describe the process of development
reduces the exposed, energized silver halide crystals into black, metallic silver. softens the film emulsion
Describe the process of rinsing
stops the development process and is necessary to remove the developer from the film
Describe the fixing process
removes the unexposed, unenergized silver halide crystals from the film. hardens the film emulsion
Describe the washing process
removes all excess chemicals from the emulsion
why do we do the drying process?
films must be dried before they can be handled for mounting or viewing
What forms can film processing solutions come in?
How can we maintain freshness of film processing solutions?
What 2 chemicals can we find in the developer solution? What do these chemicals do?
What does the preservative in the developer solution do?
prevents developer solution from oxidizing in the presence of air. sodium sulfite-agents
What does the accelerator do in the developer solution?
softens gelatin of film emulsion. sodium carbonate-activates
What does the restrainer in the developer solution do?
prevents development of unexposed crystals. potassium bromide
What can we find in the fixer solution? What do these do?
What is a darkroom?
A completely darkened environment within which x-ray film can be handled and processed to produce diagnostic radiographs
What are the 5 requirements of a dark room?
Location and size of darkroom
- large enough to accommodate film processing equipment and allow ample work space