LASERS CERTIFICATION EXAM 2024
Theorized the concept of stimulated emission – correct answer Einstein
Theorized that an excited electron will spontaneously return to its ground state – correct answer Bohr
First ruby laser was created in _ by . – correct answer 1960, Ted Maiman
reported in 1965 that a ruby laser could vaporize enamel. – correct answer Stern and
Sognnaes
First pulsed Nd:YAG laser released in and cuts tissue. – correct answer 1990, soft tissue
In _ the first dental hard tissue was FDA cleared and is called _. And the laser a year
later. – correct answer 1997
Er: YAG laser
Er, Cr: YSGG
The word LASER is an acronym standing for __. – correct answer Light Amplification by
Stimulated Emission of Radiation
Laser parameters include what 3 things? – correct answer 1)Duration of exposure
2)Fiber Diameter
3)Wavelength
Lasers are:
______chromatic?
directional? coherent or noncoherent? emitted from a stimulated _____. – correct answer monochromatic: made of a single
wavelength (visible or infrared)
unidirectional
coherent (all peaks and valleys of each wave travel in unison)
active medium
What states can the active medium be in? – correct answer solid, gas, semiconductor
What type of active medium is used in Er: YAG? – correct answer solid state using crystal matrix (erbium
laced yttrium, aluminum and garnet)
What type of gas is used when the active medium is sealed in an air tight chamber? – correct answer
CO2
Diode lasers have what type of active medium? – correct answer semiconductor
what photons form the laser? – correct answer light that leaks from the output coupler
Stimulated emission: – correct answer atoms of the active medium are stimulated to a higher energy
level–> released as a photon as the atom returns to a more stable lower energy level.
Amplification – correct answer Released photons can go on to stimulate more atoms in the crystal, thus
producing more photons
Energy density depends on what 3 things? – correct answer energy, divergence (tendency of a laser
beam to spread outward=laser beam diameter increases), and distance
Energy is measured in __ – correct answer Joules (millijoules)
The term “LASER” is an acronym for: – correct answer light amplification by stimulated emission of
radiation
The very first therapeutic laser (of any class) received 510k market clearance from the United States
Food and Drug Administration (FDA) in .And the first class 4 therapy laser gained FDA clearance in . – correct answer 2002 , 2003
In the late 1960’s he made the observation that the hair of shaved mice grew back more rapidly after
exposure to low power laser light. As a result he is known as the ‘Father of Laser Therapy’. Who is he? –
correct answer Dr. Endre Mester
In 2015 a world-wide panel of experts designated the term __ to describe the therapeutic
use of light. – correct answer photobiomodulation, or PBM
Surgical lasers cut tissue; and are used for performing surgery, removal of ‘lumps and bumps’, and other
ablative laser procedures. What is the mechanism of action for surgical lasers? – correct answer
Photothermal: the laser light has a very high power density and causes excessive heating of water
molecules, which vaporizes the water, “explodes” the cells, and thus cuts the tissue.
Therapeutic lasers help to enhance tissue healing, and are used for pain management, wound and injury
healing, and other uses. What is the mechanism of action for therapeutic lasers? – correct answer Both
A and C are correct (Photochemical and Photobiostimulative)
Wavelength measures the distance between two corresponding points on adjacent light waves, for
example from one peak to the next, or from one trough to the next. Which is the proper unit for
measuring wavelength? – correct answer nanometers (nm)
t or f- Compared to healthy cells, compromised or unhealthy cells in tissues that are injured or damaged
are more ‘reduced’. This means that damaged cells will more readily absorb oxygen; and therefore
damaged tissues will respond more readily to laser therapy. – correct answer true
t or f- The “electromagnetic spectrum” is used to describe the entire range of radiation – including
gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves, and radio waves. Therefore, it is
appropriate to refer to all of these as “electromagnetic radiation”. – correct answer true
t or f- Power is the rate of energy delivery, and Power = Energy ÷ Time (Power equals energy divided by
time)
Proper units are: 1 Watt = 1 Joule ÷ 1 second. (One Watt equals one Joule per second.) – correct answer
true
Photons of laser light are absorbed by water molecules, hemoglobin, mitochondrial enzymes and other
tissue components. The general name for these components is ___. – correct answer
chromophores
When therapeutic laser light is absorbed by enzymes in the mitochondria the result is an increase in the
production of , which leads to normalization of cell function, pain relief, and healing. – correct
answer adenosine tri-phosphate (ATP)
t or f- The Platinum 4 therapeutic laser delivers these wavelengths: 650, 810, 915 & 980 nanometers;
and the H1 delivers these wavelengths: 650, 810 & 915 nanometers. – correct answer true
The level of laser radiation to which a person may be exposed without hazardous effects or adverse
biological changes in the eye or skin is the . – correct answer Maximum Permissible Exposure
(MPE)
__ is one of the unique properties of laser light. It arises from the stimulated emission
process which provides the amplification. Since a common stimulus triggers the emission events which
provide the amplified light, the emitted photons are “in step” and have a definite phase relation to each
other. – correct answer Coherence
The acronym “LED” stands for _. – correct answer Light Emitting Diode
Which statement best describes the main difference between Laser and LED? – correct answer Laser
light is coherent, LED light is not.
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