Chapter 6

Question 1

As low as reasonably achievable. Any dose that can be reduced without major difficulty, great expense, or inconvenience should be reduced or eliminated.

Answer 1

the alara principle

Question 2

Communication
Working knowledge of quality radiographs
Continuing education

Answer 2

the operator technique

Question 3

Intraoral technique choice

Exposure factors

Answer 3

Technique standards

Question 4

Filtration – absorbs the unnecessary wavelengths
Are these wavelengths long or short?
Inherent 
Added – How thick is the aluminum?
Total – 1.5 mm - 2.5mm minimum
Collimation – What does it do?
PID
Lengths and shapes

Answer 4

Patient Protection Measures

Question 5

Film speed/image sensors
Holding devices
Lead apron - .25mm thick 
Thyroid collar – can be separate
Optimal film processing

Answer 5

Patient protection

Question 6

One should spend the least amount of time, at the greatest distance, with most shielding, to receive the least exposure to radiation.”

Answer 6

Operator protection

Question 7

Distance – how far and where should the operator stand from the source of radiation?

Answer 7

6 feet, and behind a protective barrier if possible.

Question 8

What are the factors that affect the time of the radiation for the radiographer?

Answer 8

Drifting tubehead
Radiation leakage
Film stabilization
If you do not have to retake an image, then your time is limited.

Question 9

Area monitoring

Answer 9

onsite survey to measure the output of the dental x-ray unit.

Question 10

What are the different types of personnel monitoring ?

Answer 10

Film badge and the TLD.

Question 11

How does the film badge work?

Answer 11

Rediosensitive film in a plastic/metal holder lined with filters of different materials varying in thickness. Exposure is determned by “reading” the processed film electronically.

Question 12

How does the TLD (thermo-luminescent dosimeter) work?

Answer 12

Contains crystals, usually lithium fluroide, that absorb radiation. Crystals are heated after beind exposed, and the energy emitted, in the form of visible light, is proportional to the amount o radiation absorbed. It is extremely accurate. Reports are taken every 3 months.

Question 13

What does the council of radiation protection do?

Answer 13

Works to assure that dental patients receive the latest treatment in radiation safety.

Question 14

What is the Maximum Permissible Dose (MPD) for occupational workers?

Answer 14

50 mSv per year – whole body dose

Persons under 18 and pregnancy don’t apply.

Question 15

What is the Maximum Permissible Dose (MPD) for the public?

Answer 15

5mSv per year

Question 16

What steps can the dental radiographer take to adopt an ALARA ethic?

Answer 16

Utilize good exposure technique along with holding device to reduce retakes.
Utilize good processing technique to reduce retakes.
Use the fastest speed film or screen/film combination possible.
Utilize a lead apron and thyroid collar.
Ensure that the patient receives proper radiograph prescription.
Ensure that x-ray equipment has proper filtration and collimation. A long rectangular PID is recommended.

Question 17

Who has the ethical responsibility to adopt ALARA?

The dental assistant, the dental hygienist, the Dentist. Or all of the above?

Answer 17

all of the above

Question 18

What is the minimum total filtration that is required by an x-ray machine that can operate in ranges above 70 kvp?

Answer 18

2.5 mm of aluminum equivalent

Question 19

What is the federally mandated size of the diameter of the primary beam at the end of the PID?

Answer 19

2.75 inches.

Question 20

During dental x-ray exposure the lead/lead-equivalent thyroid collar with apron should be place on?

Answer 20

All patients

Question 21

List 3 radiation protection organizations

Answer 21

American Dental Association
(osha)
(EPA)