Radiation Biology

Question 1

SI (International Unit)

Answer 1

a conventional unit that measures the dose of radiation absorbed by a person (deposited in the human tissue)

Question 2

Kerma (Gy)

Answer 2

Kinetic Energy Released in MAtter measures exposure in the air
kinetic energy transferred from photons to electrons.

Question 3

Conventional unit rad or SI unit gray (Gy) measures what?

Answer 3

Amount of energy deposited in human tissue.

Question 4

The biological risk of exposure to radiation is measured using which units?

Answer 4

Conventional: rem
SI Unit: sievert (Sv)

Question 5

Equivalent dose (Sv)

Answer 5

Compares the biologic effects of different types of radiation on tissue or organ.

Question 6

Effective Dose (E)

Answer 6

the effective dose is used to estimate the risk in humans.

Question 7

Radiobiology

Answer 7

the study of the effects of ionizing radiation on living systems.

Question 8

Direct exposure

Answer 8

Can cause free radicals

Question 9

Indirect exposure

Answer 9

formation of organic free radicals

Question 10

Free radical

Answer 10

Water interacts with x-ray photons and biologic molecules.

Water is converted into hydrogen and hydroxyl free radicals.

free radicals are toxin to tissues.

Question 11

Most important type of DNA change

Answer 11

the breakage of double-strand DNA.
can lead to cell killing, carcinogenesis and heritable effects.

Question 12

Deterministic effect

Answer 12

Radiation injury causing injury of large number of cells.

Question 13

Stochastic effect

Answer 13

Sublethal affect results to cancer formation, or heritable mutation.
ex. leukemia

Question 14

What plays a major role in cell death?

Answer 14

Caspases

Question 15

What gene is responsible for apoptosis?

Answer 15

p53

Question 16

Dose rate vs exposure rate

Answer 16

High dose rate causes more damage than exposure to the same total dose given at a lower dose rate.

Question 17

Radiosensitive oral malignant tumors

Answer 17

squamous cell carcinoma

Question 18

ALARA

Answer 18

As low as reasonably achievable

Question 19

Which structure is radiopaque?

Answer 19

Lamina dura

Question 20

Which structure is radiolucent?

Answer 20

PDL
Mandibular canals

Question 21

X-rays and pregnant women

Answer 21

Take only necessary x-rays

Question 22

If patient has poor hygiene which type of x-rays should dentist order?

Answer 22

FMX

Question 23

Red XCP is used for

Answer 23

bitewings

Question 24

If patient has excellent hygiene which x-ray would you order?

Answer 24

bitewings

Question 25

PA’s are useful for which procedure

Answer 25

RCT

Question 26

How many PA’s and bitewings in an FMX

Answer 26

14 PA’s
4 bitewings