4. Contents :
Session II
Applications of lasers in periodontics
hypersensitivity
non surgical therapy
LANAP
Laser assisted surgery
Implant therapy
5. Introduction
LASER : light amplified by stimulated
emission of radiation.
Laser is a device that emits light through a
process of optical amplification based on
stimulated emission of electromagnetic
radiation
6. Introduction
Lasers have completely changed the concept of
dental treatment since three and half decades
of 20th century.
After the invention of ruby laser by Maiman in
1960, laser has become the most magnetizing
technology in dentistry.
Lasers have been used in initial periodontal
therapy, surgery, and also in implant treatment.
In many countries Laser has become a part of
the dental armamentarium.
7. Historical
Background
1917, Stimulated emission: Albert Einstein
1959, Principle of MASER: Schalow and
Townes
1960, Synthetic ruby laser: Theodore
Maimam
1961, The first gas laser and first
continuously operating laser: Javan et al.
8. 1964, Treatment of caries: Goldman
1968, CO2 laser: Patel et al.
1971, Tissue reactions to laser light and
wound healing: Hall and Jako et al
9. Dr.Hibst
1974, Nd:YAG laser: Geusic et al.
1977, Ar laser: Kiefhaber
1988, Er:YAG laser: Hibst and Paghdiwala
1989, Nd:YAG laser, soft tissue surgery:
Midda et al.
10. “L in Light “
Monochromatic :
One single wavelength of light (one single
color)
The wavelength of light is determined by the
amount of energy released when the
electrons drop to a lower orbit.
Coherent
Organized – each photons move in a step
with the others.
This means all photons have identical
wavelength & frequency.
11.
12. Directional / Collimated :
all the emitted waves are
parallel & the beam
divergence is very low.
It should be concentrated &
focused
13. “A”
A in laser stands for amplification.
Amplification means the very intense
beam of light that can be created.
The lasers, initially activated by few
photons; but than many more photons are
generated.
The initial light is amplified to make a very
bright compact beam.
14. “S”
Stimulation means that the photons are
amplified by stimulating an atom to
release more photons.
An atom can exist in an excited state,
similar to an bow when it is stretched.
When the atom relaxes it emits an photon.
15. “E”
Emission
The excited atom emits a photon when
another photon comes by.
It was Einstein who described the process
of stimulated emission.
Photons bounce between the two mirrors
until enough photons are emitted, some
pass through semi silvered mirror on one
end which are seen as laser beam.
19. Terminologies
Energy : Ability to perform the work.
Joules (Nm) or millijoules
Measuring unit of most dental application
Power : Measurement of work completed
over time.
1 watts = 1 J/s
Average power :Power that affects the
tissue on a sustained basis over a period of
time
20. Pulse duration/width :Emission
length of time of individual pulse
1 Hertz = 1 pulses/ second
Power density or energy
density/fluence : concentration
of photons in unit area-W or J/
square centimeter .
It refers to the actual amount of
energy reaching the tissue within
the actual spot.
21. Peak power : watts (J/s)
Pulse energy : W * s = Joules
Frequency = Hz (pulse / second)
Duty cycle % = PD * 100 / (PD +
relaxation time)
Pulse repetition rate : Pulse/ second
22. Components
of Laser
A laser medium, which can be a solid, liquid, or
gas.
An optical cavity or laser tube having two
mirrors, one fully reflective and the other one
partially transmissive, which are located at either
end of the optical cavity.
An external mechanical, chemical, or optical
power source which excites or “pumps” the
atoms in the laser medium to higher energy
levels
23.
24. Laser Delivery
system
Articulated arms (with mirrors at joints) –
for UV, visible, and infrared lasers.
Hollow waveguides (flexible tube with
reflecting internal surfaces) – for middle
and far infrared lasers .
Fiber optics – for visible and near infrared
lasers
25.
26. Classification
I. Based on Active Medium
a) Solid State
b) Gas
c) Semiconductors
d) Excimer.
II. Mode of action
a) Contact mode (focused or defocused) -
Ho:YAG ; Nd: YAG
b) Non-contact mode (focused or
defocused) - CO2
26
27. III. Based on application
a) Soft tissue laser - Argon, Co2, Diode;
Nd:YAG.
b) Hard tissue laser - Er : YAG
c) Resin curing laser - Argon
IV. Based on Level of energy emission:
a. Soft lasers (UV & visible): He-Ne; Ga-
Arsenide.
b. Hard lasers (High energy level, Infrared):
Er:YAG laser ; CO2 laser.
27
30. Contact & Non-
Contact Mode
Contact mode
provide easy access
Removal of periodontal pocket lining
Non-contact mode
Useful for following various tissue contours
But loss of tactile sensation(careful about
tissue interaction with laser energy)
Invisible lasers Separate aiming beam (laser
or conventional light) delivered coaxially along
the fiber or waveguide
31.
32. Focused mode
Small diameter beam hits tissue
0.1mm to 0.35mm or larger.
Also known as cut mode e.g. biopsy sample
Defocused mode
Focal spot away from tissue plane
Wider area of tissue is vaporized
Laser intensity or power density is reduced
For the removal of inflammatory papillary
hyperplasia
38. Mode Locking
Mode-locking is a technique in optics by
which a laser can be made to produce
pulses of light of extremely short
duration, on the order of picoseconds
(10−12 s) or femtoseconds (10−15 s).
Active mode locking : Acoustic optic
modulator
Passive mode locking : Saturable absorber
46. Reflection
No effect on target tissue
Caries detecting in laser devices
Er lasers reflect Ti allowing safe trimming of
gingiva around implants abutments
Laser become more divergent with increasing
d/t from handpiece
Scattering
Facilitate curing of composite resin or
covering broad areas
47. chromophores
Endogenous light absorbing chemicals,
which absorbs light of specific wavelength.
Proteins : diode & Nd: YAG
Hb : diode & Nd : YAG
Melanin : Argon, KTP, diode & Nd : YAG
Water : Er: YAG & CO2
HA : Er : YAG & CO2
48. Using the principle of selective photo thermolysis, the lasers targets
different chromophores in the skin, which selectively absorbs the laser
or light energy as heat & yield the desired response.
chromophores
absorbs the light
Physical, chemical,
mechanical
temperature changes
may occur.
This energy travel at
different wavelength
& is absorbed by the
“target”.
49. Photo thermal
interactions
Incising tissue or coagulating blood.
Predominate for soft tissue procedures.
Heat is generated during this procedure
for which great care must be taken to
avoid damage.
49
50. Different temperature effect
Between 75 – 100
°C
• Tissue shrinkage
& dehydration
• Vaporization &
carbonization
• Irreversible cell
death
Between 55 – 75
°C
• Increase of
blood viscosity –
coagulation
Between 35 & 55
°C
• Vasodilation &
hyperthermia –
blood supply
51. Photo
chemical
interactions
Occurs when photons causes a chemical
reaction.
Molecular targets are Cyt C oxidase
(absorbed in NIR region) or photoactive
porphyrins
Cellular effects are on mitochondria with
the effect of inc. ATP production,
modulating ROS
52. The primary photon acceptor within the
(red – IR) region is mixed valence
(partially reduced) cytochrome c oxidase
Primary photon acceptor within the (blue)
region is avoproteins. (NADH
dehydogenase)
53. Results
Increased cellular proliferation & migration.
(particularly fibroblasts)
Modulation in levels of cytokines, growth factors
& inflammatory modulators.
Influence on the activity of secondary messenger
(CAMP, Nitric Oxide, Calcium ion)
Increased tissue oxygenation
Increased healing of chronic wounds,
improvement in injuries, pain reduction & nerve
damages.
54. Photomechanical interaction include Photo-
disruption or photo-disassociation, which is the
breaking apart of structures by laser light.
Photoelectrical interactions include Photo
plasmolysis which describes how tissue is
removed through the formation of electrically
charged ions and particles that exist in a semi-
gaseous high energy state.
54
55. Photodynamic
therapy
(photochemical)
Photodynamic therapy is a treatment
modality based on the activation of
exogenous photosensitizing agents by a light
source to produce cell damage.
This action was first observed in 1900 by
Raab, who realized that a protozoon could be
killed in the presence of acridine excited by a
visible light.
55
60. Safety google to be worn by operator & patient
Lock the room during treatment
Never look directly into the laser beam
Never point the beam at any person except the
treated area
Never use the laser in place of inflammable
anesthetics
Never step on or abruptly bend the fiber optics
cable.
Never move the laser machine during operation
61. Other
Advances
Waterlase system is a revolutionary dental
device that uses laser energized water to cut
or ablate soft and hard tissue.
Periowave™, a photodynamic disinfection
system, utilizes nontoxic dye (photosensitizer)
in combination with low intensity lasers
enabling singlet oxygen molecules to destroy
bacteria (Thomas, 2006).
63. Argon Laser
488 nm, 514 nm
Peak abs. in red pigments & tissue with abundant Hb
Poor absorption in HA, water
Tissue effect is thermal nature
Specific use :
root planning & curettage – photocoagulation &
vaporization of tissue in periodontal pockets
Gingival retraction – excellent hemostasis &
coagulation (creating a temp. b/t 90 – 100 °C) which
coagulates the blood vessels and remove the sulcular
depth
64. Gingivectomy & gingivoplasty
Oral lesions therapy : removes the surface
epithelium & necrotic tissue, disinfect the
wound.
Lasers are applied until lesions has desiccated
appearances & necrotic cells has glazed app.
Tissue welding : arterial welding
Adv : preserve the mechanical properties of
tissues & decrease hyperplasia.
65. Diode laser
Semiconductor laser which Change electric energy to
light energy
Gallium arsenide chip & Aluminum
Delivery : fibroptically in continuous wave or gated
pulse
Portable, No special power, No cooling connection,
No heat
Quiet, affordable
More powerful, less traumatic wavelength 800 – 980
nm, invisible
Well abs. by soft tissue & poorly by hard tissue
66. Nd : YAG
laser
Mode : Coagulation (100°C), central vaporization
Specification : 1.06 µ
Can be combined with CO2 (combo laser) or
KTP
Oral indications :
Coagulation of very vascular lesions or near
major vascular blood vessel. (excellent
hemostatic ability)
Gingivectomy
Frenectomy
67. Disadvantages
Retina at risk
Penetration can cause inadvertent
blood loss
Edema more than CO2 lasers
In 1995, FDA cleared it for gingival
surgery
May 7, 1997 – treatment tooth decay
Oct 1998 – use in childrensThis retinal burn, caused by a
Nd:YAG rangefinder, resulted in
nearly complete
68. HO : YAG
With holmium
2120 µ wavelength
Used for soft tissue excision
Frequently used in arthroscopy in TMJ
Compared to CO2 lasers, HO:YAG lasers
offers better hemostasis & is safe &
effective to use in bone & cartilage.
69. KTP lasers
Potassium Titanyl phosphate
Mode : cutting with moderate coagulation
Specification : 0.53 µ wavelength
Can be combined with Nd: YAG laser
Oral indication : for use in vascular lesions,
tonsillectomy.
70. CO2 laser
Mode of application : Vaporization , cutting
(>100°C)
Specification : 10.6 µ wavelength
First laser used routinely for soft tissue surgery in
dentistry.
Used in non contact mode for tissue ablation
Heat diffusion & heat accumulation occurs
Coagulation of small blood vessels in depth of
tissue
Prevent bleeding from those vessels.
71. Oral
Indications:
Use routinely in patients with oral lesions
with blood dyscrasias Oral indications :
Excision of premalignant lesions
Excision biopsy
Hemi glossectomy
Adhesive macrovascular/ microneural
diseases.
72. Disadvantages
Risk of corneal damage
Hemostasis mayn’t be adequate in very
vascular areas as tongue
It was reported that the use of CO2 laser
is unfavorable because of the loss of the
odontoblastic layer. (Wigdor et. al. 1993)
Pig eye hit by 80 watt
CO2 laser
73.
74. Erbium laser
specification : 2940 µ wavelength
Excellent absorption in apatite crystals &
water
Minimum thermal damage seen, & removes
infected & softened carious dentin to the
same degree as bur treatment
Adv : because of very high absorption in
water, only a few layers of tissue is removed
with each pulse energy , so removal &
reshaping can proceed with precision.
75.
76. Apicectomy, osteotomy of bone & impacted
teeth - because of excellent bone healing
capacity.
Laser adjacent to pulp – causes local damage
compared to burs.
Lab studies has shown :
1 time laser t/t = daily fluoride t/t
Laser t/t of enamel can inhibit caries t/t by
50 %
Malik A, Parmar G, Bansal P, Bhattacharya A, Joshi
N. Effect of laser and fluoride application for
prevention of dental caries: A polarized microscope
analysis. J Dent Lasers [serial online] 2015
Female, age 12: maxillary
frenectomy and gingivoplasty
with erbium laser.
77. Laser irradiation of dental hard tissues
modifies the Ca/ P ratio, reduced the
carbonate to phosphate ratio & leads to
formation of more stable & less acid
soluble compounds.
Threshold pH for enamel dissolution was
reportedly lowered from 5.5 to 4.8 & the
hard tissues were 4 times more resistant to
acid dissolution.
Morioka T, Tagamori S, Oho T. Acid resistance of
lased human enamel with Erbium: YAG laser. J Clin
Laser Med Surg 1982;June:215-7.
Left photo: Er,Cr;YSGG Waterlase MD. Note:
Illumination. Right photo: Class II preparation with
no anaesthetic and no handpiece
79. Laser doppler flowmetry – to monitor
gingival & pulpal blood flow & to assess
tooth vitality.
Laser doppler vibrometry - To measure
tooth mobility
Laser fluorescence (Diagnodent) – for caries
detection
80. Conclusion
With conventional mechanical instruments, complete
access and disinfection may not be achieved during the
treatment of periodontal pockets.
Lasers have the potential advantages of bactericidal
effect, detoxification effect, and removal of the
epithelium lining and granulation tissue, which are
desirable properties for the treatment of periodontal
pockets.
Thus, laser systems, applying the ablation effect of
light energy which is completely different from
conventional mechanical debridement, may emerge as
a new technical modality for periodontal therapy in
the near future.
81. References :
Lasers in dentistry. Leo J Miserendino / Robert M Pick
Aoki A, Sasaki KM, Watanabe H, Ishikawa I. Lasers in
nonsurgical periodontal therapy. Periodontology 2000
2004;36:59-97.
Maiman TH. Stimulated optical radiation in ruby. Nature
1960;187:493-4.
Ishikawa I, Aoki A, Takasaki AA, Mizutani K, Sasaki KM,
Izumi Y. Application of lasers in periodontics: True
innovation or myth? Periodontology 2000 2009;50:90-126.
Coluzzi DJ. Fundamentals of dental lasers: science and
instruments. Dent Clin North Am 2004;48:751-70
Bains VK, Gupta S, Bains R. Lasers in periodontics: An
overview. J Oral Health Community Dentistry 2010;4(Spl):29-
34.