Chapter 05: Radiation Protection
Iannucci: Dental Radiography, 5th Edition
MULTIPLE CHOICE
1. Which of the following should you do prior to taking x-rays to protect your patient from
radiation exposure?
a.
Proper film processing
b.
Proper prescribing of radiographs
c.
A lead apron
d.
A thyroid collar
2. The “Guidelines for Prescribing Dental Radiographs” state that
a.
dentulous adult recall patients at increased risk for caries should have posterior
bite-wing examinations at 12- to 24-month intervals.
b.
x-rays are not taken on patients who are pregnant unless absolutely necessary.
c.
edentulous adults should have posterior bite-wing examinations at 12- to 36-month
intervals.
d.
dentulous adult recall patients who are not at increased risk for caries should have
posterior bite-wing examinations at 24- to 36-month intervals.
3. Inherent filtration in the dental x-ray tubehead
a.
includes filtration that takes place when the primary beam passes through the glass
window of the x-ray tube, the insulating oil, and the tubehead seal.
b.
includes the placement of aluminum discs in the path of the x-ray beam between
the collimator and the tubehead seal.
c.
alone meets the standards regulated by state and federal law.
d.
is equivalent to approximately 5.0 mm of aluminum.
4. Added filtration in the dental x-ray tubehead
a.
refers to the placement of tungsten discs in the path of the x-ray beam between the
collimator and the tubehead seal.
b.
filters out shorter-wavelength x-rays from the x-ray beam.
c.
results in a lower-energy beam.
d.
results in a more penetrating useful beam.
5. State and federal laws require that dental x-ray machines operating above 70 kVp have a
minimum total (inherent plus added filtration) of ____ mm of aluminum filtration.
a.
1.5
b.
2.0
c.
2.5
d.
5.0
6. The collimator ____________
a.
is always round.
b.
restricts the size and shape of the x-ray beam.
c.
is a solid piece of aluminum.
d.
is fitted within the copper stem beneath the molybdenum cup.
7. A circular collimator produces a cone-shaped beam that is __________ inch(es) in diameter.
a.
<1
b.
1.25
c.
2.75
d.
5.0
8. A rectangular collimator
a.
restricts the beam 3 times more than a circular collimator.
b.
restricts the beam less than a circular collimator.
c.
decreases patient exposure considerably.
d.
is considerably larger than a size 2 intraoral receptor.
9. Which of the following types of position-indicating devices (PIDs) produces scatter radiation?
a.
Rectangular
b.
Conical
c.
Round
d.
Square
10. Which type of PID would be most effective in reducing patient exposure?
a.
Conical
b.
A 16-inch round PID
c.
An 8-inch rectangular PID
d.
A 16-inch rectangular PID
11. The thyroid collar
a.
is recommended for all intraoral exposures.
b.
is recommended for all extraoral exposures.
c.
is placed over the patient’s chest and lap and extends to protect the thyroid.
d.
is recommended for both intraoral and extraoral exposures.
12. The lead apron
a.
is recommended for intraoral exposures.
b.
is not recommended for extraoral exposures.
c.
is an option; use is not mandated by any state or federal law.
d.
is used to protect the thyroid gland.
13. ____-speed film is currently the fastest intraoral film available.
a.
D
b.
E
c.
F
d.
G
14. On some dental x-ray machines, only the ____________ can be altered; the other parameters
are preset by the manufacturer.
a.
kilovoltage
b.
exposure time
c.
PID length
d.
milliamperage
15. Which of the following can you do after x-ray receptor exposure to reduce(s) the amount of
x-radiation your patient receives?
a.
Proper placement of the lead apron
b.
Proper image retrieval
c.
Proper instrument technique
d.
Selecting proper exposure settings
16. The primary dictum of operator protection guidelines is that the operator must
a.
remain in the room with the patient while the receptor is being exposed.
b.
avoid the primary beam.
c.
hold the receptor in the patient’s mouth with their own finger.
d.
hold the tubehead during x-ray exposure.
17. In order to avoid the primary beam while taking dental images, you should stand at a
____-degree to ____-degree angle to the beam.
a.
0; 45
b.
45; 90
c.
90; 135
d.
135; 180
18. Radiation monitoring can be used to protect the dental radiographer and includes monitoring
of
a.
equipment
b.
personnel
c.
both equipment and personnel
d.
drywall for residual radiation
19. A film badge
a.
is worn at waist level by the patient.
b.
is worn at waist level by the operator.
c.
is clipped to the shirt pocket of the operator.
d.
is clipped to the shirt pocket of the patient.
20. (1) Radiation legislation varies greatly from state to state. (2) For example, in some states a
dental radiographer must successfully complete a radiation safety examination before he or
she may expose dental x-rays.
a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second statement is false.
d.
The first statement is false; the second statement is true.
21. According to the current recommendations (2003) of the National Council on Radiation
Protection and Measurements, the current MPD for occupationally exposed persons is
___________/year.
a.
500 millirem
b.
5.0 rem
c.
50 rem
d.
5000 rem
22. According to the current recommendations (2003) of the National Council on Radiation
Protection and Measurements, the current MPD for an occupationally exposed pregnant
women is the equivalent of
a.
50 mSv/year.
b.
0.05 Sv per month.
c.
0.5 mSv/year.
d.
0.01 mSv/month.
23. The acronym for the maximum dose permitted in a year is
a.
MPD—maximum permissible dose
b.
MPD—maximum possible dose
c.
MAD—maximum accumulated dose
d.
MAD—maximum allowed dose
24. The ALARA concept states that all radiation must be kept
a.
as long as readily achievable.
b.
as low as reasonably allowable.
c.
as low as reasonably achievable.
d.
as long as reliably achievable.
25. You are in charge of monitoring the film badges. Film badges are checked on a quarterly
basis. Your co-worker is 4 months pregnant. The badge registered 5.0 Sv for the previous
quarter. Based on the National Council on Radiation Protection and Measurements (NCRP),
what information should you give the dentist?
a.
The reading is well below the allowable limit. Nothing needs to be done.
b.
The reading is at the allowable limit. Nothing needs to be done.
c.
The reading is at the allowable limit. She has reached her maximum dosage and
cannot have any more exposure during the pregnancy.
d.
She has exceeded her maximum dosage and cannot have any more exposure
during the pregnancy.
26. You are 36 years old. What is your cumulative occupational dose recommended by the
National Council on Radiation Protection and Measurements (NCRP)?
a.
360 millirems
b.
360 mSv
c.
180 millirems
d.
180 mSv
27. Your patient is a 5-year-old boy who you have been seeing since he was 3 years old. He is
always eating candy and drinking cola beverages. Six months ago he had A, J, and T restored.
One year ago he had B, I, and L restored. Which of the following should you do regarding
taking radiographs?
a.
Take bite-wings and occlusal radiograph today.
b.
Insurance covers bite-wings once a year, take the dental images in 6 months.
c.
Re-evaluate in 1 year for the need for dental images.
d.
Dental images are taken every 2 years.
28. Your next patient is a 35-year-old man who you have been seeing for the past 10 years. The
only treatment he has needed since coming to the dental practice has been his 6-month
“prophys.” He has no periodontal issues and is on a 6-month recall cycle. You last took four
bite-wing images 1 year ago. Which of the following should you do?
a.
Take bite-wings during this appointment.
b.
Take the images in 6 months.
c.
Take the images in 1 to 2 years.
d.
No images will be needed for 5 years.