who is responsible for prescribing dental radiographs?
the dentist
the ____, ____, and ____ are considered before prescribing radiographs.
number
type
frequency
t/f the radiographs should be a predetermined number, and at set intervals.
False
should be set up on an individual basis, never predetermined number or time interval
what are the two types of filtration for dental x-ray tube head?
inherent filtration
added filtration
what kind of filtration is it when the primary beam passes through the glass window of the xray tube, the insulating oil and the tubehead seal.
inherent filtration
what type of filtration refers to the placement of aluminum disks in the path of the xray beam between the collimator and the tubehead seal in the dental xray machine
added filtration
what is total filtraton?
inherent plus added filtration
who controls total filtration?
state and federal laws
dental xray machines operating at or below 70 kVp require how much aluminum filtration?
minimum total of 1.5 mm
a dental xray machine operating above 70 kVp is required how much aluminum filtration
minimum total of 2.5 mm
what is used to restrict the size and shape of the xray beam and to reduce patient exposure?
collimation
what are the two types of collimators? describe
round-2.75 inches in diameter (much larger)
rectangular-retricts to slightly larger area than size 2 film (greatest reduction of exposure)
what are the three basic types of PIDs?
conical-not used
rectangular-8" and 16"
round- 8" and 16"
what 4 things can be used during xray exposure to limit the amount of radiation to patient?
thyroid collar
lead apron
fast film
film-holding devices
what is a thyroid collar?
flexible lead shield that is placed securely around the patients neck to protect the thyroid glad from scatter radiation
what is a lead apron?
flexible shield placed over the patients chest and lap to protect the reproductive and blood-forming tissues from scatter radiation
what is the most effective method of reducing a patients exposure to xradiation (during exposure)
using fast film
t/f F-speed is the fastest intraoral film available. t/f fspeed film provides an additional 20% reduction in exposure over espeed film.
True
True
how does the radiographer control the exposure factors?
adjusting the kilovoltage peak, milliamperage and time setting
all ____ must be avoided.
retakes
to produce diagnostic films the radiographer must have a thorough _____ of _____ most often used in dental radiography.
knowledge
techniques
after exposing patients xray what two things must be done to protect the patient against xradiation.
proper film handling
proper film processing
what rule is the operator protection guidelines based on?
the dental radiographer must avoid the primary beam
what is the distance the dental radiographer must stand away from the xray tubehead?
6 feet
when standing at 6 feet during exposure isn't possible what must the radiographer do?
stand behind a protective barrier
to avoid the primary beam which travels in a ____ ____, the dental radiographer must be positioned _____ to the primary beam or at a _____ degree to _____ degree angle to the beam.
straight line
perpendicular
90
135
what two things should the dental radiographer never do during xray exposure?
never hold the film in place for a patient
never hold the tubehead
what two types of radiation monitoring are recommended?
equipment monitoring
personnel monitoring
what is equipment monitoring?
leakage radiation-any radiation that is emitted from the dental tubehead, except the primary beam
what are the characteristics of personnel monitoring, film badge?
radiographic film in plastic holder
worn at waist level
stored in radiations safe area
never worn when undergoing radiation exposure
badge is evaluated
what year did they standardize performance of xray equipment?
1968
what year did they address the issues of the education and certification of persons using radiographic equipment?
1981
t/f the regulations for dental radiography are the same in every state established by the federal government?
false
differ from state to state
define maximum permissible dose
maximum dose equivalent that a body is permitted to receive in a specific period of time..amount of radiation the body can endure with little or no injury
what is the occupational maximum permissible dose?
5.0 rems/year
what is the nonoccupational and pregnant maximum permissible dose?
.1 rems/year
define maximum accumulated dose?
occupationally exposed workers must not exceed an accumulated lifetime radiation dose.
what is the formula for maximum accumulated dose?
MAD=(N-18) X 5 rems/year
MAD=(N-18) X 0.05 Sv/year
define ALARA concept
states that all exposure to radiation must be kept to a minimum or "as low as reasonably achievable."
patient education on radiation protection can take two forms what are they?
