4. processing section.ppt

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PROCESSING

Definition: It is the process that produces a visible

lasting image from a latent image created by

the x- ray.

It includes developing, fixing,washing and

drying.

x-ray→light senstive silver bromideon the

film→latent image→processing→final lasting

image.



Processing methods: 1-Manual method.

2-Automatic method.



The manual method:

It is the simplest way to

develop, rinse,fix and wash

the dental film.



4-Thermometers and timer.

There are 2 types of thermometers : a-Tank thermometer that contain centigrat

and feherenhiet scale,it also

contain a steel clip to hold it in the tank.

b-Floating stirring rod thermometer that can

stirr the solution and measure the temp.

the timer is used to adjust needed time fordeveloping and fixing.



5-Safe light.

Slight illumination is needed in the dark

room to perform the Processing steps, it is usually

yellow or red as x-ray film emulsion is less senestive

to it than the blue and green color,GBX-2 red filter is

used to get the needed light.

6-Processing hanger:

Used to hang the films in it.



Dark room

The place in which the processing

steps take place, it should be cleanand equipped.



Steps of the manual processing: 1-Stirr the solution.

2-Check the solution level.

3-Check the solution temp.

4-Turn safe light on.



5-Unrap the exposed film.

6-Develop the film 5 min 70F

(The main function of the

developer is to reduce the silver

in the exposed silver bromideinto black metallic silver the

unexposed silver bromide is not

affected by the developer).



7-Rinse the film for 20-30 sec.

8-Fix the film for 8-10 min(Themain function of the fixer is to

make the unexposed silver

bromide soluble to be washed by

water and leave a translusent

area,so it sometimes calledclearing agent ).



Developing solution:

1-Reducing agent →Metol

Hydroquinone

2-Activator →Sodium carbonate

3-Preservative→Soduim sulfite

4-Solvent →

Water5- Restrainer

potassium bromide



The fixer solution

1-fixing agent → Ammonium thiosulfate.2-Acidifier → Acetic or sulfuric acid (stop devoloping).

3-Hardener → Aluminium chloride(harden the emulsion)

4-Preservative→Sodium sulfite.

5-Solvant →water.

9-Wash the film (15 min) to remove the chemicals and

Disolve the unexposed silver bromid.

10-Dry the film.



Automatic method:

In this method the process of processingdepend on a roller that transport the film on

the various

solutions(developer,water,fixer,water and finally dryer).

The main advantages here are:

1-Decrease the processing time.

2-Constant film quality.



Film

Exit Dryer

(heater, fan)

Film

Entry

Wash

Automatic ProcessorAutomatic processors come in various shapes and sizes, but

they all function the same. The film is inserted in the inlet slot

where it is fed into a series of rollers (see photo next slide).These rollers transport the film through the developer, fixer,

wash and dryer and the film exits the processor ready to

mount. The rollers “squeegie” the excess chemicals off of the

film as it exits each solution; no rinse is needed between the

developer and fixer. (Click to process film).

FixerDeveloper

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