1
LASERS
LASERS CERTIFICATION Exam
Questions with Correct Verified
Answers Latest Update
(2024/2025) Guaranteed Pass
1. Which lasers operate in free running pulsed mode? - ANS
✔Nd:YAG, Erbium lasers
Shorter pulses ______ peak power (increase or decrease?)
2. Which laser uses shorter pulses? - ANS ✔increases
Hard tissue lasers
3. Define Thermal relaxation - ANS ✔ability of the target tissue to
absorb heat produced by laser interaction
4. When does thermal relaxation occur? soft or hard tissue? - ANS
✔ONLY occurs during soft tissue procedures
5. Describe thermal relaxation in the three types of lasers. - ANS
✔-Continuous mode:
No thermal relaxation (damaging heat can build in the tissue quickly)
-Gated wave mode:
half on/half off exposure and the ability of the tissue to absorb the heat is
limited
LASERS CERTIFICATION
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LASERS
-Free running pulsed:
Thermal relaxation occurs the most (each pulse is very short so there is
adequate time between each pulse to allow the tissue to absorb and
dissipate the heat to minimize thermal damage: allows for lowered post op
discomfort and predictable healing so some procedures can be done
without anesthetic)
** analogy is if a finger is moved rapidly through
a candle flame it will not burn as the tissue can absorb and dissipate the
momentary high heat Placing the finger in the flame and holding it there
will cause rapid thermal damage.**
6. Describe the 4 types of interactions the laser has with the target
- ANS ✔1) Absorption: chromophores absorb the photons, the light
energy is then converted into thermal or mechanical energy to
perform work (Preferred)
2) Reflection: The laser beam bounces off the surface with no penetration
or interaction. (usually NOT preferred)
3) Transmission: laser can pass through superficial tissues to interact with
deeper areas. (Nd:YAG and diode lasers)
4) Scattering: laser energy enters the target tissue will scatter in various
directions.
7. Define Chromophore: - ANS ✔Light-Absorbing compounds or
molecules normally occurring in tissues that are attractors of specific
wavelengths
LASERS CERTIFICATION
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LASERS
8. What are absorbed by Nd: YAGs and Diodes? - ANS ✔pigments:
hemoglobin and melanin
9. What part of the eye can diodes and Nd:YAGs cause damage to? -
ANS ✔Retina (because it has pigment)
10. What are absorbed by Erbium and CO2? - ANS ✔Water and
erbium also does hydroxyappetite
11. Which lasers penetrate tissue deeply? - ANS ✔Nd: YAG
( shorter near infrared wavelengths) penetrate tissue deeper than
the longer mid infrared wavelengths like Erbium and CO2
12. Which lasers are soft tissue cutting? - ANS ✔Nd:YAG, Diode
lasers,CO2, and Erbium (all 4)
13. Which lasers are hard tissue cutting? - ANS ✔Er: YAG,
Er,Cr:YSGG (all erbium)
14. What are the five types of biological effects that can occur
once the laser photons enter the tissue? - ANS ✔Fluorescence,
photothermal, photodisruptive/photoacoustic, photochemical, photo
biomodulation
15. Define Fluorescence: - ANS ✔Determines the size of the
carious lesion to diagnose and manage early carious lesions
16. Define Photothermal: - ANS ✔-Occurs when the
chromophores absorb the laser energy and heat is generated to
perform work.
LASERS CERTIFICATION
LASERS
LASERS CERTIFICATION Exam
Questions with Correct Verified
Answers Latest Update
(2024/2025) Guaranteed Pass
1. Which lasers operate in free running pulsed mode? - ANS
✔Nd:YAG, Erbium lasers
Shorter pulses ______ peak power (increase or decrease?)
2. Which laser uses shorter pulses? - ANS ✔increases
Hard tissue lasers
3. Define Thermal relaxation - ANS ✔ability of the target tissue to
absorb heat produced by laser interaction
4. When does thermal relaxation occur? soft or hard tissue? - ANS
✔ONLY occurs during soft tissue procedures
5. Describe thermal relaxation in the three types of lasers. - ANS
✔-Continuous mode:
No thermal relaxation (damaging heat can build in the tissue quickly)
-Gated wave mode:
half on/half off exposure and the ability of the tissue to absorb the heat is
limited
LASERS CERTIFICATION
, 2
LASERS
-Free running pulsed:
Thermal relaxation occurs the most (each pulse is very short so there is
adequate time between each pulse to allow the tissue to absorb and
dissipate the heat to minimize thermal damage: allows for lowered post op
discomfort and predictable healing so some procedures can be done
without anesthetic)
** analogy is if a finger is moved rapidly through
a candle flame it will not burn as the tissue can absorb and dissipate the
momentary high heat Placing the finger in the flame and holding it there
will cause rapid thermal damage.**
6. Describe the 4 types of interactions the laser has with the target
- ANS ✔1) Absorption: chromophores absorb the photons, the light
energy is then converted into thermal or mechanical energy to
perform work (Preferred)
2) Reflection: The laser beam bounces off the surface with no penetration
or interaction. (usually NOT preferred)
3) Transmission: laser can pass through superficial tissues to interact with
deeper areas. (Nd:YAG and diode lasers)
4) Scattering: laser energy enters the target tissue will scatter in various
directions.
7. Define Chromophore: - ANS ✔Light-Absorbing compounds or
molecules normally occurring in tissues that are attractors of specific
wavelengths
LASERS CERTIFICATION
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LASERS
8. What are absorbed by Nd: YAGs and Diodes? - ANS ✔pigments:
hemoglobin and melanin
9. What part of the eye can diodes and Nd:YAGs cause damage to? -
ANS ✔Retina (because it has pigment)
10. What are absorbed by Erbium and CO2? - ANS ✔Water and
erbium also does hydroxyappetite
11. Which lasers penetrate tissue deeply? - ANS ✔Nd: YAG
( shorter near infrared wavelengths) penetrate tissue deeper than
the longer mid infrared wavelengths like Erbium and CO2
12. Which lasers are soft tissue cutting? - ANS ✔Nd:YAG, Diode
lasers,CO2, and Erbium (all 4)
13. Which lasers are hard tissue cutting? - ANS ✔Er: YAG,
Er,Cr:YSGG (all erbium)
14. What are the five types of biological effects that can occur
once the laser photons enter the tissue? - ANS ✔Fluorescence,
photothermal, photodisruptive/photoacoustic, photochemical, photo
biomodulation
15. Define Fluorescence: - ANS ✔Determines the size of the
carious lesion to diagnose and manage early carious lesions
16. Define Photothermal: - ANS ✔-Occurs when the
chromophores absorb the laser energy and heat is generated to
perform work.
LASERS CERTIFICATION
