What is an x-ray?

Question 1

What is an x-ray?

Answer 1

a wave packet of energy called a ‘photon’

Question 2

What does a radiograph require?

Answer 2

millions of photons

Question 3

What type of radiation is an x-ray

Answer 3

Ionising radiation

Question 4

In Ionising radiation,
Phonton energy is ……
Wave length is ……..

Answer 4

very high

very short

Question 5

What happens to the photons when hit a patient

If very high energy…….
If low energy …….

Answer 5

high : transmitted unchanged

low: photons absorb and disapear, others scatter and loose energy

Question 6

5 properties of an x-ray

Answer 6

travel in straight lines,
require no medium,
originate at atomic level,
interact at atomic level,
can damage human tissue

Question 7

What 3 effects of x-radiation principally concern the dental profession?

Answer 7

somatic deterministic effects, somatic stochastic effect, genetic stochastic effects

Question 8

2 aims of radiation

Answer 8

prevent the detrimental deterministic effects (follow scientific rules)
limit the probability of stochastic effects to acceptable levels (determine the level of risk)

Question 9

x-ray photons are a form of ………. ……… ………… radiation and are a form of …… spectrum

Answer 9

high energy electromagnetic,

electromagnetic

Question 10

What is the same about x-rays and gamma rays and the difference between them?

Answer 10

Both ionising radiation consisting of waves with high photon energy
Difference: gamma rays naturally occur, x-rays are man made

Question 11

What happens to the low energy photons?

Answer 11

Go into the patient and stop, absorbed and disappears

Question 12

What are x-rays undetected by?

Answer 12

human senses, cant feel, see or hear them BUT can still damage human tissue

Question 13

Define somatic deterministic effects

Answer 13

Somatic refers to body of person being irradiated
Deterministic means what will definitely happen ‘certainty’
Can be acute or chronic

Question 14

Explain somatic deterministic effects of acute and chronic affects

Answer 14

acute: short term, e.g. death or radiation sickness
chronic: long term, e.g. hair loss, damage to the blood vessels

Question 15

In dentistry we do not use doses …… enough to cause ……….. effects

Answer 15

large,

deterministic

Question 16

Define somatic stochastic effects

Answer 16

somatic - person being x-rayed

stochastic - chance effects that might happen due to deterministic effects which will definitely happen

Question 17

Example of a somatic stochastic effects

Answer 17

cancer induction, can develop without any amount of radiation and every exposure to ionising radiation carries possibility of causing the damage

Question 18

Important aspect of stochastic effects is that the …….. of exposure to …….. radiaition does not affect the severity of the damage induced, only the …… of it happening

Answer 18

size,
ionising,
probability

Question 19

If during a dental exposure ……. change is …… then the cancer can develop asif patient received high amount of radiation

Answer 19

malignant,

induced

Question 20

Define genetic stochastic effects

Answer 20

Genetic material of patient being irradiated is affected but the resultant damage becomes apparent in their children
Can develop with any amount of radiation but very unlikely with dental x-rays as reproductive organs need to be irradiated for genetic material to be damaged

Question 21

What must outweigh the other before considering an x-ray?

Answer 21

potential benefit outweighs the risk, as always potential risk of causing damage