Radiology: Chapter 7 Dental X-ray Film and Processing Methods

Size 3 film has a longer ______ dimension and will record more teeth than size 2 film

Horizontal

Developer contains two reducing agents:

Hydroquinone & Elon (Hydroquinone slowly to build density & elon is fast to build contrast)

What happens when gelatin is placed in liquid?

It swells and exposes the silver halide crystals to the chemicals in the developing solution

There are FIVE sizes of intraoral film, what are they? The larger the number, the larger the size

0, 1, 2, 3, and 4

Dental film emulsion is about __-__% silver IODIDE

1-10%

The basic steps of processing dental x ray films:

1. Developing 2. Rinsing (automatic processors often omit this step) 3. Fixing 4. Washing 5. Drying

What 4 things do film packets consist of?

1. Film (one or two films) 2. Black Paper Wrapping (adds additional light protection) 3. Lead Foil (located in the back, absorbs scatter radiation, clarity) 4. Moisture Resistant Outer Wrapping

The fixing steps: (3)

1. Stops further film development, establishing permanent imagine on film 2. Removes (dissolves) unexposed silver halide crystals 3. Hardens (fixes) the emulsion

Dental film emulsion is about ____-____% silver BROMIDE

90-99%

Silver halide crystals are compounds of a what?

A halogen (bromine or iodine) with another element

Rinsing preserves the _____ of the fixer and prolongs it's useful life

Acidity

Classified as screen film, is larger in size and designed for use outside the mouth

Extraoral film

What film speed has the greatest sensitivity to radiation

F

True or false Film size is found on the back side of the intraoral film packet

FALSE IT IS NOT

The LARGER the crystals, the ____ the film speed, resulting in less radiation

Faster

The American National Standards Institute (ANSI) groups film speed using letter of the alphabet: speed group A die the slowest through F, which is the _____ film available

Fastest

What provides support for the fragile emulsion and strength for handling x Ray film?

Film base

Small films suitable for intraoral radiography are made into what are called...

Film packets

After brief rinsing, the film is immersed into the what?

Fixer solution

Physical pressure and bending can ____ the film

Fog

The use of high speed film has made it possible to reduce patient exposure to radiation to a _____ of the time formerly deemed necessary

Fraction

During radiation, the x-rags strike and ionize some, but not all, of the silver halide crystals resulting in the formation of a...

Latent (invisible) image

During x Ray exposure, crystals within the film emulsion become energized with a...

Latent image

The faster the FILM SPEED, the _____ radiation required

Less

Silver halide crystals are ____ and ____ sensitive

Light and x Ray

Will all of the radiation penetrating the patient's tissue reach the film emulsion?

No

True or False The MAIN function of the GELATIN is to keep the silver halide crystals evenly suspended over the base

True

True or false All automatic processors require water

True

True or false Individual packets should also be kept in a shielded area

True

True or false Stray radiation can fog film

True

True or false The tube side is usually solid white, and the tab for opening the film packet is on the back side

True

The front side or ____ side of the film packet faves the tube (radiation source)

Tube

Fixing agent (clearing agent) that removes unexposed and any remaining undeveloped silver halide crystals (responsible for radiopaque appearance)

ammonium thiosulfate or sodium thiosulfate

______ is composed of gelatin

Emulsion

What largely replaces Manuel processing because of its ability to produce a large volume of radiographs in less time? (5 minutes)

Automatic film processing

The _____ side of the film packet faces away from the radiation

Back

What provides support for the fragile film emulsion?

Base

The role of the DEVELOPER solution is to reduce the exposed silver halide crystals within the film emulsion to _____ ____ ____

Black metallic silver

X Ray film is sensitive to white light and white light in the darkroom can _____ the film or cause it to fog

Blacken

After the film is completely fixed, it is washed in running water to remove any remaining traces of ______

Chemicals

The blue tint enhances ______ & _____ quality

Contrast and image

To prevent fogging, film should be stored in a ____, dry place, at what temperature?

Cool 50-70 degrees (30 to 50 humidity)

Currently, only what 3 speed films are available?

D, E, and F

Film fogging is the _____ of the finished radiograph caused by one or more of these factors

Darkening

Provides an area where x Ray films can be safely handled and processed

Darkroom

The ______ is especially subject to oxidation in the presence of air and loses its effectiveness quickly

Developer

In this case, the ______ and _____ with the oxygen in the air is what is causing oxidation

Developer and fixer

A thermometer is used for Manuel processing to determine the temperature of the...

Developer solution

During which step are the exposed silver halide crystals reduced to metallic silver?

Developing

Final step is _____ Films may be air dried at room temp or dried in a heated cabinet

Drying

The emulsion side appears ___ and ___ when observed under sage light conditions in the dark room

Dull and lighter

Different than x Ray film and is exposed by the action of infrared and ultraviolet light rather than by x rays

Duplicating film

To make a copy of a radiograph, the emulsion side of the film is placed against the original radiography with the _____ side up

Nonemulsion

Which side contains an antihalation coating?

Nonsmulsion side

How many sides of duplicating film is coated with emulsion?

One

Film should be stored in its original packaging in an area shielded from radiation

Original

Weakened chemistry occurs though _______, the union of a substance

Oxidation

Film used in dental radigraphy is _____ film that has been especiallt adapted in size, emulsion, speed, & packaging

Photographic

Films used in Dental radiography have a thin, flexible, clear, or blue-tinted ______ base

Polyester

This transforms the latent image, which is produced when the x Ray photons are absorbed by the silver halide crystals in the emulsion (invisible and stable)

Processing

All exposed films should be kept safe from ____ until processing

Radiation

All radiographic film is extremely sensitive to:

Radiation Light Heat Humidity Chemical fumes Physical pressure

Basically, the developer is responsible for creating the film's ____ appearance

Radiolucent

The purpose of the rinsing step is to remove as much of the ______ developer as possible before placing the film in the fixer solution

Rinsing

______ refers to the AMOUNT of radiation required to produce a radiograph of acceptable density

SPEED (sensitivity)

Exposed primarily by a fluorescent type of light given off by special emulsion coated intensifying screens

Screen film (indirect-exposure film)

Film is sensitive to AGING, having a ____ ____ determined by the manufacturer

Shelf life

The nonemulsion side appears ___ and ___ when observed under sage light conditions in the dark room

Shiny and darker

A supercoat later of gelatin does what as it dries to protect the emulsion from handling, leaving a SMOOTH SURFACE that becomes a radiograph

Shrinks

In radiography, as well as in I'll photography, the other element is what?

Silver

Most automatic processors consist of _____ tanks for the developer, fixer, water, and drying solution

Three

Emulsion is composed of gelatin, in which CRYSTALS of what are suspended?

Silver halide salts

What size film is especially designed for small children and is also called pedo or pedodontic film?

Size 0

What size film may also be used for children, but can be used for the anterior teeth on adults? (Ideal for places where oral cavity is narrow)

Size 1

What size film is generally standard or referred to as PA (periapical film) Used to take both periapical and bitewing radiographs in adults and children with large oral cavities

Size 2 (most selected size)

What size film comes with a preattached bite tab and is used exclusively to take bitewing radiographs?

Size 3

What film is the largest and are used exclusively for taking occlusal radiographs?

Size 4

** What factors can determine film speed? (3)

Size of silver halide crystals Thickness of the emulsion Addition of special radiosensitive dyes

Of these three factors, which is MOST important in increasing film speed?

Size of the silver halide crystals in emulsion

However, imagine sharpness is more distinct when the crystals are _____

Small

which ingredient removes the unexposed/undeveloped silver halide crystals from the film emulsion?

Sodium thiosulfate

When duplicating film is exposed to ultraviolet light from the duplicating machine, the ____ _____ records the copy

Solarized emulsion

Automatic processor has ability to regulate the _____ of the processing solutions and the time of the developing process

Temperature

If not thoroughly ____, chemicals will continue to react within the dried emulsion and degrade the image over time

Washed

Manuel processing can be used to produce a _____ ____ without a darkroom in about 30 seconds. (Rapid or chairside processing)

Working radiograph

Are silver halide crystals sensitive to radiation? (Retain the latent image)

Yes

Is the film speed printed on the back side of each individual film packet?

Yes

What is the function of the lead foil in the film packet?

absorb backscatter radiation