Proper safety precautions must be observed by all
persons working in or near an area where X-rays are
being generated. X-rays can be dangerous. Long term
overexposure to radiation may result in loss of hair,
redness and inflammation of the skin, blood count
change, cell atrophy (wasting away), ulcerations,
sterility, genetic damage, cancer, leukemia, and death.
There are safety measures designed to protect the
patient and the health care team from the dangers of
overexposure to radiation and the operation of X-ray
equipment. You must observe these safety measures
when working in radiology. Your command will have
instructions and standard operating procedures (SOP)
for the operation of dental radiographic (X-ray) units
and equipment. You will be required to read these
procedures if you are newly assigned to the radiology
department. There are other numerous responsibilities
that include providing radiology support for oral
diagnosis, log maintenance, infection control, testing
for quality control, and processor maintenance.
A number of precautions are taken to prevent the
patient from being exposed to inappropriate diagnostic
radiation. The decision to order dental radiographs is
determined by the dental officer on a case by case basis
for each patient. Only a dental officer is authorized to
order and diagnostically interpret dental radiographs.
Perhaps the most important safety measure is the
responsibility of the assistant: When taking
radiographs, you should always have patients wear
lead aprons and thyroid collars to shield their
reproductive organs and thyroid glands. There is
only one exception to this rule; when obtaining a
panorex radiograph, the thyroid collar is not used
since it blocks part of the X-ray beam. In addition,
always ask a female patient whether or not she is
pregnant or if pregnancy is questionable, before taking
radiographs. If she is pregnant, consult the dental
Other radiation safety measures include X-ray
machines that have built-in safeguards that filter out
harmful radiation and restrict the central X-ray to the
smallest possible area. Fast film is used to shorten
expos ure time; and only essential radiographs are
taken on patients.
Figure 1-1.Environmental dosimetry radiation film badge.
When you work near a source of radiation, your
X-ray department will be issued an environmental
dosimetry radiation film badge (fig. 1-1).
feet from the tube head and never in the direct line of
radiation during expos ure. These film badges
Appropriately placed environmental film
badges are used to monitor stray radiation that may
occur in and around the X-ray department. The
badges are placed in the X-ray room behind the
technicians protective lead-lined barrier or at least 6
contain X-ray sensitive film in a light-tight packet.
The film packets are collected every 6 to 7 weeks.
After collection, the film is sent to the radiation
detection laboratory for processing and evaluation.
Any abnormally high readings (i.e., greater than
0.010 REM [Radiological Equivalent Mammel])
shall be referred to the Radiation Health Office for
When you take radiographs on a patient, observe
the following precautions to avoid unnecessary
exposure to radiation:
NEVER stand in the path of the central X-ray
beam during exposure.
NEVER hold the X-ray film packet in the
patient's mouth during exposure.
NEVER hold the tube head or the tube head
cylinder of the X-ray machine during exposure.
ALWAYS stand behind a lead-lined screen
during an exposure.
X-RAY FILM LOG
Another portion of radiation safety is to account
for all radiographs that are taken. An X-ray film log