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1. “When a flower doesn't bloom, you fix the
environment in which it grows, not the flower.”
Good Morning

2. Lasers in Periodontics
Dr. Suman Mukherjee
Final Yr MDS

3. Contents :
Session I
Introduction
History
Terminologies
Components
Classification
Laser tissue interactions
Advantages & Disadvantages
Safety
 lasers used in periodontics
Conclusion & references

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.

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.

17. “R”
Radiation
In general term, means given off from an
object.
For lasers, refers to the photons which are
being emitted.

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

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

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

28. Based on
potential hazard

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

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

34. Defocus : Coagulate
In focus : Incise
Pre focus : deep thermal damage

35. Laser emission
modes
Continuous mode : means laser is on
the whole time it is turned on.
pulse mode : has on & off periods

37. Q switching means
too much lower pulse
repetition rate. Much
higher pulse energy.

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

40. Laser Tissue
Interaction
Two types :
Wave length dependent
Wave length independent
40

41. 41
Interaction of light with biological tissue
(wavelength dependent mechanism) (aboud, 2005)
Photochemical
interaction
Biostimulation
(LLT)
Photodynamic
therapy (PDT)
Bond breaking
Photoablation
Photothermal
Interaction
Coagulation
Terminal stress
Carbonization
melting
Vaporization

42. 42
Interaction of light with
biological tissue
(wavelenght independent
mechanism)
(aboud, 2005)
Wavelength
independent
Plasma formation
Photo
disruption
Plasma induced
ablation

43. Pigmentation
Water content
- laser wavelength
- emission mode
Most important interaction
Shorter wavelength
(500 – 1000 nm)
Pigmented tissue
& blood elements
Longer wavelength
Water & HA
Absorption

45. Tissue effects :
Absorption
Photo chemical interaction
PDT
LLLT ( Bio stimulation )
Photo thermal therapy
Photo mechanical interaction
Photo disruptive
Photo accoustic
Photo electrical therapy
Photo plasmolysis
45

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

56. Advantages
&
disadvantages
Anesthesia
Bleeding
Pain
Time
Suturing
Cost
Post op complications

57. Advantages
&
Disadvantages
Healing
Dentist comfort
Procedure
Team work
Experience

58. Safety

59. Ocular injury
Tissue hazard
Environmental
hazard
Combustion
hazard
Electrical
hazard

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).

62. Lasers in periodontics

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

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.

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

78. Laser diagnostic

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.