What causes film fog?
When the film is exposed to radiation or light other than that needed to expose the film.
List the types of film fog causes (3)
chemical, light and scatter radiation
Does duplicating film have one or two sides of emulsion?
where should emulsion side of duplicating film be placed?
next to films being duplicated
Duplicating film has direct positive emulsion meaning that...
If more film density is needed the exposure time is shortened.
When is a film/screen combination used?
In extra oral radiography
Are intensifying screens removable on flexible cassettes used for extra oral radiography?
Are intensifying screens removable on rigid cassettes?
Do intensifying screens reduce exposure time?
What are the two phosphor types of intensifying screens?
1. Calcium tungstate phosphor (blue light)
2. Rare earth element (green light and phosphor of choice)
List the 4 types of image receptors we use today
2. Film/screen combinations
3. Electronic sensors
4. Gamma cameras
Name the 3 types of film being manufactured today
When was the first dental radiograph taken?
When did Kodak FIRST market a pre packaged dental film?
When did Kodak provide the first machine made film?
When did Kodak market 2 different speeds of film?
1923, regular and extra fast
When was double coated emulsion film first put out?
What is the purpose of the lead foil?
1. Absorb unused radiation
2. Prevent backscatter radiation from fogging film
What are the 4 components of a dental film?
1. Film Base
2. Adhesive Layer
3. Film Emulsion
4. Protective Layer
What is Halide made of and what is it sensitive to?
1. Silver and halogen
2. Radiation or light
Name the 2 types of halide crystals found in film emulsion