Flashcards in Lecture #1 Deck (32):
When Does Ionizing radiation occur on the radiation spectrum?
10^15 or Ultraviolet light
What are the Natural Sources of Radiation?
What are the man made sources of radiation?
CT Scans 24%
Consumer Products 2%
Gamma rays and X rays are what type of radiation?
What is not a form of ionizing radiation?
What is Becquerel (Bq)?
Si unit to messure the radioacctivity of a material
1 Bq=2.7X10^-11 Ci
just a fact you might want to know
How is exposure measured?
or Roentgen (R)
How is Absorbed dose measured?
How is equivalent dose measured?
1Sv= 100 rem
What has higher Linear Energy Transfer (LET) than photons?
What is Effective dose
measure the estimated risk to humans in different tissues
What is Equivalent dose
The amount of radiation needed to be harmful... measures different types of radiation
what is Absorbed dose
Energy deposited in a kg of a substance by the radiation
how is effective dose measured?
Define direct Effect
Photon or secondary e- ionizes biologic macromolecules
Radiolysis of Water... What is it?
Photon that ionizes water causes free radicals
Define Indirect effect
intermediate step to mess up macromolecules... photon hits something then that something hits the organism
How much does Direct and Indirct effects occur from x-rays?
1/3 and 2/3 of the damages respectfully
What is the primary cause of radiation induced cell death?
Damaged to the DNA
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
What cells have the Highest sensitivity to radiation?
Undergo little/no differentiation
What are some organs that have high sensitivity to radiation?
Define Stochastic Effect
There is no threshold and there will always be radiation effect... you will die
What are 3 guiding principles to reduce dental exposure?
ALARA stands for what
as low as reasonably achievable
dentists need what in place? (2)
Radiation protection program
good radiation safety practices
When should a dentist prescribe a x-ray?
Health History Review
susceptibility to dental diseases
What films should we use?
E or F speed film
By how much does rectangular collimators reduce exposure?
What are the 2 types of Ionizing Radiation?
1.) Particulate Radiation
2.) Electromagnetic Radiation