Quality Resource Guide

Radiographic Quality Assurance for Film Imaging Systems 7th Edition

www.metdental.com

the chemicals is necessary periodically due to

degradation as a result of oxidation. Based on a

processing workload of 30 intraoral films per day,

chemicals should be completely replaced at least

every three to four weeks.

Automatic replenishment systems are available

for some models of automatic processors. The

ready-mixed developer and fixer solutions for these

systems are attached by placing the tubing into

the developer or fixer replenishment bottles. It is

important to change the bottles before they become

completely empty and to make sure the tubing does

not become clogged. The frequency with which

replenishment bottles need to be changed depends

on the workload.

Specially designed developer and fixer chemistries

are necessary for clinical situations that require

immediate viewing of processed radiographs in 30

seconds. These rapid processing chemicals may

be used with D and F speed films. After viewing, the

films must be returned to the fixer for the full fixing

time according to the manufacturer’s instructions.

Note that it is imperative that the appropriate

processing chemistry be used for rapid processing.

Waste Management

The practitioner should become familiar with the

requirements of the Resource Conservation and

Recovery Act of 1976. This law provides, generally,

that processing chemicals (processing effluent)

and lead foil packing (waste solids) should be

disposed of properly to keep a safe environment.

These items should not be disposed of in the

trash or in the drain unless treated. Based on the

amount of waste produced, a variety of options

are available to dental offices to safely eliminate

the hazardous waste. Generally, a licensed waste

hauler should recycle hazardous waste, such as the

lead foil found

in the film packet. Lead recycling programs are

also available. Local companies for lead or silver

reclamation can be identified through an internet

search. Terms that may be used are: “silver

recycling”, “lead recycling”, “dental film recycling”

or similar terms. Processing solutions that contain

5 mg/L or more of silver are also considered a

hazardous waste. Silver estimation papers can

be used to monitor silver content levels. These

strips of paper will measure the amount of silver

in the processing solutions. Management options

such as silver reclaiming units should be used to

remove silver from the fixer solution. In addition,

some companies will buy scrap film for silver

recovery. State and local regulations may vary, so

it is recommended that each dental office check

with their State Hazardous Waste Management

Agencies and Water Pollution Control Agencies to

determine if they comply.

Film Storage and Cassettes

Unexposed film should be stored in a cool dry

area. Expiration dates should be monitored and

the film with the nearest dates should be used first.

Exposed films should be stored in a “Safe Area” to

prevent double exposure. Extraoral film should be

stored with the box on end to prevent artifacts from

occurring due to pressure marks on the emulsion.

Intensifying screens, located inside of the film

cassette, should be handled carefully to prevent

damage. In addition, cassettes should be cleaned

and inspected monthly according to manufacturer’s

directions. After cleaning, an antistatic agent can

be applied.

Quality Assurance for the

Operatory

All x-ray equipment requires proper installation and

calibration upon purchase. The National Council

on Radiation Protection and Measurements and

the American Academy of Oral and Maxillofacial

Radiology have recommended that each of the

following components be checked and calibrated

on an annual basis. Although many of these

tests can be performed and monitored by dental

personnel, most are probably best done by a

qualified technician with the proper equipment.

Resources for detailed information on each specific

test are provided in the resource list.

Other Considerations for

Quality Assurance

Film should be handled carefully during processing

to prevent fingernail marks or scratching of the

image prior to hardening and drying of the image.

Handling the film by the edges will help prevent

these errors from occurring.

Films should also be

rinsed properly to prevent yellowing of the image

over time.

Patient shielding (thyroid and abdominal) should

Table 1 - Activities Performed by Office Personnel

This table provides a summary of quality assurance activities that current literature suggests dental personnel should perform on a daily or

monthly basis.

Area or Type of

Equipment

Quality Assurance Activity

Frequency

Clean darkroom

Trash, chemical spills, etc.

daily

Processor

Sensitometry, stepwedge images, spectroline, etc.

daily

Check view boxes

Replace bulbs as needed and keep view box plexiglas clean.

monthly

Clean screens/cassettes

Keep extraoral screens clean with damp clean cloth. Check for good contact between screen and film.

monthly