Operator Protection
Chapter 5
Operator Protection
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The Guidelines for the dental radiographer
are based on the following rule:
The dental radiographer must avoid the
primary beam.
Operator protection guidelines include
recommendations on
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Distance
Shielding
Positioning
Distance Recommendations
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The operator must stand at least 6 feet away
from the x-ray tubehead during exposure.
When maintaining this distance is not
possible, a protective barrier must to used
Shielding Recommendations
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Protective Barriers absorb the primary beam
thus protecting the operator from primary and
scatter radiation.
Whenever possible, the dental radiographer
should stand behind a protective barrier
during x-ray exposure.
Protective Barriers
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Most dental offices
achieve adequate
shielding through the
use of several layers
of thickness of
common materials
such as drywall.
Positioning Recommendations
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To avoid the primary beam, the operator
should stand PERPENDICULAR (90 degree
angle) to the primary beam OR…
At a 90 – 135 degree angle to the primary
beam.
See p. 52, Figure 5-13 of your texts.
In the absence of a barrier…
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The operator should
stand
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a minimum of 6 feet
from the patient
at an angle of 90-135
degrees from the
patient.
Final Operator Protection
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Never hold the film in place for a patient.
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Never hold the tubehead during exposure.
Radiation Monitoring
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For the Operator
And the Equipment
Leakage Radiation is any radiation other than
the primary beam which comes from the
dental tubehead.
Radiation Monitoring
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Dosimeter/ Film Badge – Is used to record
any radiation which may be received by the
operator.
Each operator has his/her own badge;
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worn during the workday
when in the clinical area
Worn at waist level
Stored in radiation-safe area when not in use.
Dosimeter/Film Badge
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After specified interval of wear, badge is
returned to the service company.
It is processed and evaluated for
exposure.
Written report is provided to the dental
office for each radiographer
Dosimeters
Radiation Exposure Guidelines
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Radiation Safety Legislation
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State and federal level
Protects patient, operator, and general public from
radiation hazards
1968: standardize performance of x-ray
equipment
1981: education and certification of persons using
radiographic equipment
DANB Radiation Health and Safety Exam required
in CT before DA can expose radiographs legally
Maximum Permissible Dose
MPD
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Defined as the maximum dose equivalent that a
body is permitted to receive in a specific period of
time;
It is based on the dose of radiation that the body
can endure with little or no injury
The regulations for MPD are established by the
National Council on Radiation Protection and
Measurement
MPD Guidlines
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Occupationally exposed persons:
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0.05 Sv/year
Non-occupationally exposed persons:
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5.0 rems/year
0.1 rem/year
0.001 Sv/year
Occupationally exposed pregnant woman:
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0.1 rem/year
0.001 Sv/yr
Operator Exposure
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While we are allowed a maximum of 5 rems
per year as personnel working with ionizing
radiation, our goal is ZERO EXPOSURE!
Maximum Accumulated Dose
MAD
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Accumulated lifetime radiation dose
Occupationally exposed workers
Formula based on worker’s age:
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MAD = N – 18 X 5 rems/year
N refers to person’s age in years
18 refers to minimum age required for person who
works with radiation
ALARA concept
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All exposure to radiation must be kept to a
minimum:
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“As Low As Reasonably Achievable”
Use every possible method of reducing
exposure to radiation to minimize risk
This includes the use of minimum exposure
time in combination with the fastest film
available.
Patient Education
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Radiographer must be prepared to answer
patient’s questions regarding radiation and
protection
Conversation about radiation protection can
take place as the radiographer prepares the
equipment and patient for exposure to xradiation
See page 53 for examples of questions or
appropriate statements
Radiation Treatment for Oral Cancer
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Radiation Therapy for the treatment of Oral
Cancer can be an effective component of
treatment, but can also have side effects.
These include:
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Cervical decay
Difficulty swallowing