Deck 5: Biologic Effects of Radiation

Question 1

To further protect our patients from excessive exposure to radiation in dental procedures, the ADA recommends the use of:

A)F-speed film and/or digital sensors
B)the use of selection criteria in ordering radiographic exams
C)rectangular collimation
D)all of the above

Answer 1

all of the above

Question 2

A tissue that is near the primary beam and receives a lot of secondary radiation is the _________.

Answer 2

thyroid

Question 3

Which of the following factors affects the response to radiation?

A)dose rate
B)total dose
C)age
D)cell sensitivity
E)all of the above

Answer 3

all of the above

Question 4

A free radical:

A)is a uncharged molecule
B)is unstable
C)has an unpaired electron in the outer shell
D)combines with molecules to form toxins
E)all of the above

Question 5

Human tissue is composed primarily of:

A)water
B)air
C)ions
D)toxins

Question 6

A tissue that lies within the primary dental beam and is very radiosensitive is the ________.

Question 7

The quality factor in measuring x-radiation is ___________.

Question 8

Identify the type of interaction with matter that occurs most frequently with dental radiation procedures:

A)no interaction
B)Thompson scatter
C)photoelectric effect
D)Compton effect

Question 9

Radiation damage to somatic cells is ________ passed on to succeeding generations.

Question 10

The single largest contributor to background radiation is:

A)medical and dental radiation
B)radon
C)cosmic radiation
D)nuclear plants
E)soil

Question 11

Radiation caries is most often seen on teeth:

A)interproximally
B)on occlusal surfaces
C)at the cervical area circumferentially
D)on the incisal edges
E)around crowns

Question 12

All of the following are traditional units of radiation measurement EXCEPT:

A)roentgen
B)gray
C)radiation absorbed dose
D)roentgen equivalent man

Question 13

Identify the largest source of artificial radiation to which the population is exposed:

A)medical and dental radiation
B)consumer products
C)nuclear accidents
D)solar radiation

Question 14

Identify this type of interaction with matter: an x-ray photon has its path altered by the atom, but no change to the atom occurs;a photon of scatter radiation is produced.

A)no interaction
B)Thompson scatter
C)photoelectric effect
D)Compton effect

Question 15

The output of a dental x-ray machine is expressed in ________.

Question 16

Identify the time between exposure to ionizing radiation and the appearance of clinical symptoms:

A)latent period
B)short-term effect
C)somatic effect
D)genetic effect

Question 17

All of the following tissues are considered radiosensitive EXCEPT:

A)lens of the eyes
B)thyroid gland
C)nerve tissue
D)reproductive cells

Question 18

The total body radiation dose from a four bitewing examination utilizing E-speed film and rectangular collimation is approximately:

A)1 hour of background radiation
B)12 hours of background radiation
C)2 weeks of background radiation
D)1 month of background radiation

Question 19

The threshold erythema dose for skin is:

A)3000 R
B)250 R per 14-day period
C)100 mR per week
D)250 mR
E)none of the above

Question 20

Describe the event when x-ray photons directly hit critical areas with the cells and cause damage to the DNA of the cells:

A)indirect effect
B)ionization
C)direct effect
D)formation of toxins