xray film

Black and white image that includes varying shades of gray, Interaction of x-rays by film emulsion, Digital radiographs à no processing, Conventional radiograph à film is subjected to processing method

Usual image receptor frequently used in dental radiograph, digital image receptor (film less) connected in computer. Advantage of this is that this uses very minimal radiation

flexible piece of polyester plastic (polyethylene teraphthalate), 0.007 inch or 0.2 mm, Transparent, slight blue tint (emphasize contrast and enhance image quality), Purpose: provide stable support for the delicate emulsion

Attaches the emulsion to the base, attach one surface to another

coating attached to both sides of the film base, Gives greater sensitivity to x-radiation, Homogenous mixture of: Gelatin Ag halidest

Suspends and evenly disperse millions of microscopic silver halide crystals over the film base, Absorbs the processing solutions and allows the chemicals to react with crystals, Made from cattle bone

Chemical compound sensitive to radiation or light, 99% sliver bromide, 1% silver iodide (adds greater sensitivity to the emulsion), The greater the size of the crystals, the faster the speed of the film

E (ekta) speed

0.7um

true

Double emulsion film, With a double layer emulsion,, less radiation can be used to produce and image

used to examine teeth and oral structures, Usually a double emulsion film: requires less radiation exposure to produce an image

placed outside the mouth during x-ray exposure, Used to examine large areas of the skull or jaws

intraoral film

Used to examine the entire tooth and supporting bone and surrounding structures, peri” – around, apex”- terminal end of the tooth root

Used to examine crowns of both maxillary and mandibular teeth in one film, Examination of interproximal of adjacent tooth surfaces, Has a wing or a tab to the tube side of the film, Patient bites on the wing to stabilize the film

Used for examination of large areas of maxilla or mandible, Patient occludes on the entire film

Contains an outer package wrapping, tube and label sides

soft vinyl or paper wrapper that seals the film contents.m, It protects the film from saliva and exposure to light

tube side

label side

radiation would pass hitting the lead foil first, radiation would be lessen and transfer to the film, quality of radiation is reduced, foggy image

radiation would transfer the image to the film first then it will hit the lead foil, as it heats the lead foil, it lessens the amount of radiation being absorbed by the patient

one corner of the x-ray has a small raised bump used to determine film orientation (right or left);, usually faces occlusal

may contain one or two films in one packet (which serves as a duplicate), identification dot – one corner of the x-ray has a small raised bump used to determine film orientation (right or left); usually faces occlusal, also helps in properly mounting the radiograph and interpretation

protective sheet that covers the film and shields the film from light

located behind the film to shield the film from back- scattered radiation that results in film fog, reduces the patient’s exposure to radiation

if the film is positioned backwards, other name: bearing bone pattern

0 – 22x31mm, 1 – 24x40mm

2 – 31x41mm

3 – 27x54mm

4 – 48x54mm

size of Ag halide crystals, thickness of emulsion, presence of special radiosensitive dyes

INTRAORAL FILM SPEED

the larger, the faster, alphabetical classification system A to F, only D and E are used in intraoral radiography, ADA and AAOMR recommends the use of E speed film, which only requires half the exposure time of D speed film and has comparable image contrast and resolution

E-speed film has thicker emulsion so there’s increased amount of Ag halide crystals

makes film more sensitive

panoramic, transcranial, cephalometric

double emulsion, direct exposure film, non screen film

single emulsion, indirect exposure film, screen film

comprises majority of extra oral films, requires the use of screen for exposure; the film is placed between two special intensifying screens in cassette holder, during exposure, screen converts x-ray energy into light, which in turn exposes the film (indirect exposure), emulsion is sensitive to fluorescent light

plastic sheet with fluorescent material called phosphors. Phosphors are materials which convert photon energy to light, used in pairs, one on each side of the film, and they are positioned inside a cassette, the purpose of a cassette is to hold each intensifying screen in contact with the x-ray film to maximize the sharpness of the image

SCREEN FILM, INTENSIFYING SCREEN, NON-SCREEN FILM

direct exposure film, primarily used in intraoral radiography, directly exposed to x-rays, used more in dental radiography

Film is adversely affected by heat, humidity, and radiation, Unprocessed film should be kept in a cool, dry place, 50-70 F, Lead lined or radiation resistant film dispensers, Used before expiration date, limited shelf life

The quality of dental radiograph is determined by its image characteristics, The ideal dental radiograph is not too light and not too dark

Overall blackness of a radiograph (darker areas represent heavier deposits of black silver particles)

Exposure factors, Subject thickness, Object density, Processing film

CONTRAST

High contrast

Low contrast

characteristics of the subject that influence radiographic contrast, Determined by thickness

characteristics of film that influence radiographic contrast

Inherent qualities, Film processing, Beam energy and intensity or kVp, Fog and scattered radiation

Inherent qualities

Film processing

Beam energy and intensity or kVp