Flashcards in Lecture #1 Deck (32):
1
When Does Ionizing radiation occur on the radiation spectrum?
10^15 or Ultraviolet light
2
What are the Natural Sources of Radiation?
Cosmic 5%
Terrestrial 3%
Radon 37%
Internal 5%
3
What are the man made sources of radiation?
X-rays 12%
CT Scans 24%
Nuclear 12%
Consumer Products 2%
other <1%
4
Gamma rays and X rays are what type of radiation?
Electromagnectic radiation
5
What is not a form of ionizing radiation?
microwaves
6
What is Becquerel (Bq)?
Si unit to messure the radioacctivity of a material
7
1 Bq=2.7X10^-11 Ci
just a fact you might want to know
8
How is exposure measured?
Coulombs/Kg
or Roentgen (R)
9
How is Absorbed dose measured?
Gray (Gy)
Rad
1Gy=100rad
10
How is equivalent dose measured?
Sievert (Sv)
or Rem
1Sv= 100 rem
11
What has higher Linear Energy Transfer (LET) than photons?
Particulate radiation
12
What is Effective dose
measure the estimated risk to humans in different tissues
13
What is Equivalent dose
The amount of radiation needed to be harmful... measures different types of radiation
14
what is Absorbed dose
Energy deposited in a kg of a substance by the radiation
15
how is effective dose measured?
Sievert (Sv)
16
Define direct Effect
Photon or secondary e- ionizes biologic macromolecules
17
Radiolysis of Water... What is it?
Photon that ionizes water causes free radicals
18
Define Indirect effect
intermediate step to mess up macromolecules... photon hits something then that something hits the organism
19
How much does Direct and Indirct effects occur from x-rays?
1/3 and 2/3 of the damages respectfully
20
What is the primary cause of radiation induced cell death?
Damaged to the DNA
21
What is Deterministic Effect?
Greater the Dose the Greater the Damage
There is an exposure threshold meaning below this there might not be any damage
22
What cells have the Highest sensitivity to radiation?
Divide regularly
Undergo little/no differentiation
23
What are some organs that have high sensitivity to radiation?
Testies
Bone
Lymphoid organs
Breasts
GI Tract
Mucous Membranes
24
Define Stochastic Effect
There is no threshold and there will always be radiation effect... you will die
25
What are 3 guiding principles to reduce dental exposure?
Justification
ALARA
Dose Limitation
26
ALARA stands for what
as low as reasonably achievable
27
dentists need what in place? (2)
Radiation protection program
good radiation safety practices
28
When should a dentist prescribe a x-ray?
after
Health History Review
Clinical assessment
Examination
susceptibility to dental diseases
29
What films should we use?
E or F speed film
30
By how much does rectangular collimators reduce exposure?
60%
31
What are the 2 types of Ionizing Radiation?
1.) Particulate Radiation
2.) Electromagnetic Radiation
32