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Which of the following force carrier particles makes up the x ray beam?

photon

1

As an x ray beam passes through matter, the intensity ______ and the mean energy _______ by removal of low energy photons

decreases, increases

2

Which of the following forms of electromagnetic radiation has greater energy than x rays?

Gamma

3

What is the primary means of dental x ray attenuation?

Compton scattering (57%)

4

The quantum theory of radiation has been successful at correlating experimental data on?

The production of x rays

5

What happens when you increase kVP on a unit?

Increase mean energy and # of photons

6

Within the X-ray tube the electrons stream from ____ to ____?

cathode (-) to anode (+)

7

What is the primary source of radiation from the X-ray tube?

Bremsstrahlung

8

What percentage of the kinetic energy of the electrons produced at the filament hitting the anode is converted into heat?

99%

9

Deterministic effect says that?

- severity proportional to dose
- threshold
- tissue effects (ex. inutero)
- not really relevant in dental radiology

10

Stochastic effect says that?

- risk proportional to dose
- no threshold
- cancer
- severity independent of dose

11

Most of the radiation exposure in the world's population from natural sources is caused by?

Radon

12

Which tissue type has most radio sensitivity?

basal cells that are rapidly dividing in oral mucosa

13

When patients have head/neck radiation they should avoid dental procedures for?

6 months

14

Which of the following is true regarding radiation therapy to the jaws of children?

radiation therapy proceeding dental calcification can destroy the tooth bud (especially if undergoing chemo)

15

Which organ has lowest susceptibility to radiation cancer?

Salivary glands

16

Dental x ray beams are responsible for what percentage of the human made exposure to radiation?

less than 1%

17

The lead foil ack used in film is positioned where?

behind the film and protective black paper so the photons are absorbed before proceeding further in the mouth

18

The average dose for the individuals occupation exposed in the operation of dental x ray equipment is about what amount of allowable exposure?

1%

19

Some states require x ray beam used in intraoral radiation to be collimated so the field of radiation to the patient''s skin surface?

circular= 7cm or 2.75 in

20

according to the linear non threshold hypothesis how much risk comes from radiation induced cancer from radiography?

possibility of some risk including carcinogenic and tissue damage when exposed to any amount of radiation

21

When taking an x ray what principle obligates the dentist to do more good than harm?

justification (part of ALARA)

22

In intraoral film speed, E and F speed film have some useful contrast image quality as D speed film?

same image quality just a lot faster so less radiation is given to the patient

23

What size dental film is used for adult bit wings?

2

24

When a dark room is used with a safe light how long before the safe light affects the quality of the image?

5 mins

25

Changing which of the following variables will result in decreased film density?

increase the focal spot to the film distance