ACR Electronics L-32 FIELD MARKER LIGHTING SYSTEM Technical Information PDF herunterladen (Seite 48)

for Devices and Radiological Health (CDRH) of the US

Department of Health and Human Services (USDHHS), has

documented that dental film development is a major problem

(Reference #15). In a typical full mouth intra oral

radiographic examination, a patient is subjected to 14 to

20 exposures.

The entrance exposure of overlapped areas

is high and can be excessive unless the film is properly

developed.

Dental radiographic

exposure guidelines have

been established by the FDA

for a routine intraoral

bitewing examination for "D"

and

"E" Speed Dental Film

(Reference #15).

These are listed in Table V.

Using the facility's clinical techniques measure the

exposure with an ionization chamber positioned at the

appropriate SSD. The obtained value should be compared to

the appropriate values in Table V.

If the exposures per

film are higher than the appropriate range, the film is

probably being under developed.

If the measured exposures

are low and the

HVL

measured in Section III-6 is not excessive,

the film is

probably being over developed.

This leads to fogging of

the processed films which diminishes radiographic contrast

and overall image quality.

Over or under development

normally is caused by an improper combination of film,

chemistry, development time and/or temperature.

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ACR Electronics L-32 FIELD MARKER LIGHTING SYSTEM Technical Information Seite 48