This document provides an overview of lasers in dentistry. It discusses the history and development of lasers, how lasers are designed and how laser light interacts with tissues. It describes common dental lasers like CO2 and argon lasers, and their applications. CO2 lasers are well absorbed in oral tissues and useful for soft tissue procedures. Argon lasers are absorbed by hemoglobin and melanin, making them good for coagulation. The document outlines the benefits of lasers for various dental procedures.

1. LASER IN DENTISTRY
• ASHISH RANGHANI
• PG PART 2
• GDCH, AHMEDABAD
UNDER GUIDANCE OF
DR. J.S SHAH
PROFESSOR AND HEAD
ORAL MEDICINE AND
RADIOLOGY
GDCH
DATE- 06/01/2017

2. CONTENT
• Introduction
• History
• Laser Design
• Laser Tissue Interaction
• Laser Effect on Tissues
• Types of Laser
• Uses of Laser In Dentistry
• Advantages of Lasers
• Disadvantages of Lasers
• Laser Safety

3. INTRODUCTION1
• Laser is an acronym, which stands
for Light Amplification By
Stimulated Emission Of Radiation
• Laser light is one specific color, a
property called Monochromacity
• Laser light possesses
characteristics: collimation
(constant beam size and shape),
coherency (identical amplitude and
identical frequency)
• The unique property of laser is that
its light waves travel very long
distances with very little
divergence
•Laser photons travel “ in phase ”
LaserPhoton’s
Coherent
Monochromatic
Collimated

4. HISTORY1
1917- Einsteen The idea of LASER
is based on
ALBERT
EINSTEIN’S
Theory of
stimulated
emission
1960 – Maiman Built the first
functioning laser
Nowadays diode lasers are being extensively used in field of dentistry.
1961 – Johnson Laser generated
from crystals of
yttrium
aluminium garnet
treated with 1-3%
neodymium
(Nd:YAG was
developed)
1962-Bennet Argon laser
developed,
Ruby laser became
the first medical
laser to coagulate
retinal lesions
1964 - Patel Developed the
CO2 Laser

5. Laser is an electromagnetic radiation & used for
Metal cutting Communications
Surgery Defense Reading

6. LASER DESIGN1,4
• The laser consists of
the following
components:
• Housing tube
• Lasing medium
• Power source
• Laser Beam Delivery
Systems

7. Housing tube or Optical cavity:
• Made up of metal, ceramic or both.
• The structure encapsulates the laser medium and
consists of two mirrors, one fully reflective and the
other partially transmitive, which are located at
either end of the optical cavity.

8. Lasing medium
Active medium: the component also called Exciting
medium
• GAS- CO2 laser, Argon
• Solid- Nd:YAG, Er:YAG
• Semiconductor Crystals- Diode

9. External power source
• It excites atom in
the laser medium to
their higher energy
levels.
• This causes the
population
inversion.
• Atoms in the excited
state spontaneously
emit photons of
light, which bounce
back and forth
between the two
mirrors in the laser
tube.

10. • As they bounce within the laser tube, they strike
other atoms, stimulating more spontaneous
emission.
• Photons of energy of the same wavelength and
frequency escape through the transmittive mirror as
the laser beam

11. Mainly two types:
Laser beam Delivery systems
Hollow tube waveguide
• It is hollow tube lined
with series of well
aligned mirror which
reflect the laser beam
from the unit of the
handpiece- CO2,
Er:YAG
Fibro optic
• Quartz silica fibers
with a handpiece-
Diode, Nd:YAG.
• This come in various
diameters, the
operator can select the
diameter (range from
200 microm to 800
microm) as per the use

12. USE OF LASER BEAM
Contact mode- The distal
end of the fibro optic is
placed in direct contact of
the target tissue
Noncontact mode- The hand
piece is held away from the
tissue and a guide is provided
to focus the beam at the
desired target tissue

13. Mode of Laser beam
Continuous mode-
• The laser wave
emits energy in
continuous mode at
average power
• Useful in ablative
procedures or
Coagulation
Pulsed mode-
• It emits the energy
from laser beam in
series of pulses with
burst of peak energy
at each pulse with a
resting time in
between

14. Spot size
• This is measure of surface area on which laser is
concentrated
• Spot size is directly related to efficiency
• Small laser spot diameters are ideal for incision and
excision.
• Laser with bigger spot size mainly applied in
ablation & hemostatic procedure

15. LASER-TISSUE INTERACTION1,3
Laser energy can be transmitted or absorbed based on the
composition of the target tissue
ABSORPTION TRANSMISSION
REFLECTION SCATTERING

16. • Absorption of the laser light by the target tissue is the primary
and beneficial effect of laser energy
• When absorbed, light energy is converted into thermal energy
Absorption
of laser
light
depend
upon:
Water content of the
tissue
Tissue pigmentation
Laser wavelength

17. Argon has a high affinity for melanin and hemoglobin in
the soft tissue.
Diode and Nd: YAG has a high affinity for melanin and
less interaction with hemoglobin.
The longer wavelengths are more interactive with water
and hydroxyapatite.
Erbium is well absorbed by hydroxyapatite and water

18. Transmission of light transfers
energy through the tissue without
any interaction and thus does not
cause any effect or injury.
This interaction is also highly
dependent on the wavelength of
laser light.

19. • Water, for example is relatively transparent to
the Nd: YAG wavelength, whereas tissue fluids
readily absorb erbium family and CO2,so that
there is little energy transmitted to adjacent
tissues.
Nd:YAG laser
would work
better in an
environment
difficult to keep
dry
CO2 laser would
be less effective
because of its
absorption by
the saliva, water
and tissue fluids

20. REFLECTION
Reflection results
in little or no absorption,
so that there is no thermal
effect on the tissue.

21. When scattered, light travels in
different directions and energy is
absorbed over a greater surface
area, producing a less intense and
less precise thermal effect

22. Laser effect on tissues2
The light energy from a laser can have four different
interactions with the target tissue.
•Photo thermal interaction
•Photo chemical interaction.
•Photo mechanical interaction
• Photo electrical interaction

23. PHOTO THERMAL INTERACTIONS
Photo ablation-, or the removal of tissue by vaporization
and superheating of tissue fluids
Type of thermal reaction depends on the
Spot size
Power density
Optical properties and composition of irradiated tissue
The principle effect of laser energy is photo thermal i.e.
conversion of light energy into heat
Light energy Heat energy

24. Effects on tissues on certain temperatures
37-50
• Hyperthermia
>60
• Coagulation, protein denaturation
70-90
• Welding of tissues
100-150
• Vaporization
>200
• Carbonization

25. There are photochemical effects from the
laser light that can stimulate chemical
reactions (e.g. the curing of composite
resin) and breaking of chemical bonds (e.g.
using photosensitized drugs exposed to
laser light to destroy tumor cells, a process
called photodynamic therapy).
PHOTO CHEMICAL INTERACTIONS

26. •Photo-disruption – shock waves by laser –rupture
the intermolecular and atomic bonds
•Photo-disassociation - which is the breaking apart
of structures
•Photo-acoustic interactions- Removal of the tissue
with Shockwave therapy
PHOTO MECHANICAL INTERACTION

27. Photo plasmolysis, tissue is removed through the
formation of electrically charged ions
PHOTO ELECTRICAL INTERACTIONS

28. TYPES OF LASER1
According to the
lasing medium
Gas laser- Argon , CO2 laser
Solid laser- Nd:YAG, Er:YAG
Semiconductor Crystals-
Diode
According to tissue
applicability
Soft tissue laser
Diode, CO2, Argon, and
Nd:YAG
Hard tissue laser
Er:YAG

29. CARBON DIOXIDE LASER3,4
• The CO2 laser first developed by Patel et al in
1964 is a gas –active medium laser that must be
delivered through a hollow tube-like waveguide
• Because of the water absorption, the CO2 laser
generates a lot of heat, which readily carbonizes
tissues.
• Since this carbonized or charred layer acts as a
biological dressing, it should not be removed.

30. Type : Molecular gas laser
Active Medium : Mixture of CO2, N2, He or H2O vapour
Active Centre : CO2
Pumping Method : Electric Discharge Method
Optical Resonator : Gold mirror coated with Al
Power Output : 10 kW
Nature of Output : Continuous or pulsed
Wavelength Emitted : 10600 nm

32. Symmetric 100 C - stationary
O - vibrates
simultaneously
along molecular
axis
Bending 010,
020
C & O vibrate
perpendicular to
molecular axis
Asymmetric
Stretching
001,
002
C & O atoms
vibrate in opposite
directions along
molecular axis

33. They are highly absorbed in oral mucosa, which
is more than 90% water. High absorption in small
volume, results in a penetration depth as
shallow as 0.2 to 0.3mm.
There is no scattering, reflection, or transmission
in the oral mucosa. Hence, what you see is what
you get
CO2 lasers cannot be delivered fiber optically.
Advances in articulated arms and hollow wave-
guide technologies now provide easy access to
all areas of the mouth
CO2 LASER

34. • Rapid soft tissue remover
and has a shallow depth of
tissue penetration, which is
important when treating
mucosal lesions.
• Beam can be focused to
create a precised
coagulation of small blood
vessels
• Specially useful for cutting
dense fibrous tissue
• Focused onto the surgical
site in a non-contact fashion
• Loss of tactile sensation is
disadvantageous, but the
tissue ablation can be
precise with careful
technique

35. Application
of CO2
laser
Mucocele
Fibroma
Epulis
fissuratum
High
frenum
attachment Precancerous
lesions
Aphthous
ulcer
Pregnancy
tumour

36. Application
of CO2
laser
Tongue tie
Exposure of
partially
erupted
tooth
Lichen
planus
Biopsies –
Incisional/
Excisional
Aesthetic
gingival re-
contouring and
crown
lengthening
Dissection
and
coagulation

37. • The active medium is ionized
argon gas.
• They are the lasers in the
blue-green visible spectrum
• Two wavelength of 488 nm blue
color and 514nm blue green
• Fibro optic delivery system
• Argon lasers work both in the
contact and non contact mode
• The small diameter flexible
glass fiber is normally used
in contact with the surgical
target tissue
• Absorbed by haemoglobin and
melanin
ARGON LASER1

38. • Argon lasers have an affinity for darker colored tissues and
also for hemoglobin, making them excellent coagulators.
Thus, an argon laser focused on bleeding vessels stop the
hemorrhage.
• It is not absorbed well by hard tissue and no particular care
is needed to protect the teeth during surgery
• Argon lasers also have the ability to cure composite resins
• The blue wavelength (488nm) is used mainly for composite
curing while the green wavelength (514nm) is mainly used
for soft tissue procedures

39.  Both the wavelengths can be used as an aid in caries
detection. When the argon laser light illuminates the tooth,
the diseased, carious area appears a dark orange red color
and is easily differentiated from the surrounding healthy
structures
 Acute inflammatory periodontal disease and highly
vascularized lesions such as hemangioma are ideally
suited for treatment by the argon laser.

40. Nd (Neodymium) – YAG (Yttrium Aluminium Garnet) LASER1
Type : Doped Insulator Laser
Active Medium : Solid active media-Yttrium Aluminium Garnet
Active Centre : Neodymium
Pumping Method : Optical Pumping
Pumping Source : Xenon Flash Pump
Optical Resonator : Ends of rods silver coated
Two mirrors partially and totally reflecting
Power Output : 20 kWatts
Nature of Output : Pulsed
Wavelength Emitted : 1.064 μm
Fiber optic delivery system
CHARACTERISTICS

41. Nd:YAG laser
• This is mostly used in hair
removal procedures.
• Also used in removing tattoos
and certain pigmented lesions.
• Useful in Intraoral Soft Tissue
Surgery (Ablating, Incising,
Excising, Coagulating)
• Periodontal surgery, sulcular
debridement
• Aphthous Ulcer Treatment
• Root canal sterilization
• Removal of Filling Materials

42. • Solid active semiconductor
• Lasing media- aluminium gallium
and arsenide
• Wavelength 800-980 nm
• The chief advantage of the diode
laser is one of a smaller size
portable instrument
• Useful in soft tissue surgeries,
ablative procedure & periodontal
treatment
• The power output utilized by the
soft-tissue diode laser is typically
between .1 and 10 watts or joules
per second
DIODE LASER1

43. • Laser energy is delivered
fiberoptically in continuous-
wave and gated – pulse mode;
used in contact with the tissue.
• Poorly absorbed by tooth
structure so that soft tissue
surgery can be performed safely
in close proximity to enamel,
dentine and cementum
• An excellent soft tissue surgical
laser indicated for cutting and
coagulating gingiva and mucosa
and for soft tissue curettage, or
sulcular debridement.

44. • Intraoral Soft Tissue Surgery (Ablating, Incising,Excising,
Coagulating)
• Aphthous Ulcer Treatment
• Sulcular Debridement Laser-assisted periodontal
curettage using a diode laser at a setting of 0.6 watts in
continuous wave mode in conjunction with root planing
and scaling procedures were then performed
• Removal of Coronal Pulp
• Tooth Whitening
• Aid in Diagnosis of Dental Caries
• Blood Flow Measurements
Application DIODE laser

45. Er:YAG laser1
• Yttrium aluminum
garnet doped with
Erbium
• They have a
wavelength of
2.94μm
• Highest absorption
in water
• High affinity for
hydroxyapatite

46. These lasers are most commonly used for the treatment of
hard tissues, teeth and bones
like Cutting,Shaving, Contouring and Resection of Osseous
Tissue
Apicoectomy
Osteotomy
Crown Lengthening
Caries removal
Soft tissue surgeries
Bone ablation
Tooth preparation

47. ADVANTAGES OF LASERS1,2,3
Less pain, little bleeding, reduced risk of infection
Minimal damage to surrounding tissues
Haemostatic effect by sealing blood vessels.
Reduction of postoperative inflammation & edema.
Dressing & suturing is not required for wound closer.
Operating time is reduced

48. Sterilization of wound due to reduction in amount of microorganism exposed
to laser irradiation
Dry surgical field and better visualization
Patient becomes free of fear & anxiety
low recurrence rates
Excellent wound healing
Laser exposure to tooth enamel causes Reduction in caries activity.
Technique is very easy, fast and safe

49. DISADVANTAGES OF LASERS1,2,3
Laser beam could injure the patient or operator by
direct beam or reflected light, causing retinal burns
Treatment is very expensive
Specially trained person is needed
No tactile sensation with the use of laser

50. Laser Hazards5
Endangers mainly two organs-
• Eyes and Skin
In case of eyes it damages retina , cornea , & the lens and
slight carelessness can destroy vision permanently.

51. LASER SAFETY5
Gloves, mask and cap should
be used by surgeons and
assistants.
Clean the area with povidone
iodine 5% solution
Patient's eye should be
protected with the eye shield
Dentist and assistants should
use wavelength-rated
spectacles
Post signs that lasers are
being used
BEFORE PROCEDURE

52. • Hold the hand piece perpendicular to
the lesion and press the foot pedal to
fire the laser. Vaporize the lesion in
coiled, centrifugal, vertical or
horizontal fashion. Vaporize the flat
lesions from the top
DURING LASER THERAPY

53. • Pedunculated lesions can be excised
by lasing from the base of the
lesion. Hold the lesion with toothed
forceps on the top, pull it to the side
on the top of the wet gauze (to
prevent charring of the normal skin).
Always use wet gauze as dry gauze
can catch fire.
• Wipe the vaporized lesions with wet
gauze. Always make sure to dry the
area or wipe the water with dry
gauze. Coagulate the bleeding spots
if any by defocusing the laser beam

54. The treated area does not require any special
postoperative care.
Suturing or dressing is unnecessary in laser surgery.
The wound is kept raw and uncovered, because there is
good hemostasis and minimal or no edema.
Avoid hot and spicy food
POST PROCEDURE CARE

55. LOW LEVEL
LASER
THERAPY 7
55

56. 03-07-2017
56
Low level laser therapy also known as
soft laser or low intensity level laser
whereas the therapy has been reffered to
as biostimulation & biomodulation
Generally operate in the visible and
infrared spectrum 600-900 nm
wavelength
Suitable therapeutic energies range from
1-10 J per point

57. 03-07-2017
57

58. 58
Increase lymphatic
flow
Leads to reduction
in swelling
Collagen synthesis in
fibroblasts & formation
of capillaries
Important in wound
healing
SECONDARY CLINICAL EFFECTS

59. 59
Reduction of
depolarization C
fibres
Decreases pain
sensation
Stimulation of
osteoblasts and
odontoblasts
Builds bone and
dentin
Decreases histamine,
bradikinins, substance
P, acetylcholine
Decreases
inflammation and pain

60. 60
USING THE APPROPRIATE DOSE
BIO STIMULATION -
For application where
you want to stimulate
(osteoblasts), use lower
doses 4J
BIO INHIBITION - For
applications where you want
to inhibit ( pain management
& reduction of inflammation )
use higher doses 8J

61. 61
INDICATIONS
Herpes
simplex
infection
Musculoskeletal
pathology
Dentinal
hypersensitivity
Wound
healing
MUCOSITIS
Aphthous
ulcer

62. Herpetic
lesion
• DIODE LASER use
0.6 watt
for 45 sec
0.7 watt
for 45 sec
0.8 watt
for 45 sec

63. Gingivectomy
procedure
• DIODE LASER used
• 0.8 to 1.2 watt
• Very light depth touch and working
short brush like strock
• Diode fibre place parallel to long axis
of tooth

64. CLINICAL APPLICATIONS OF LASERS IN DENTISTRY5,6
Pulp vitality
Indirect pulp
capping
Direct pulp
capping
Access
cavity
preparation
and orifice
enlargement

65. Vital pulp
amputation
Pulpectomy
Root canal
preparation
with lasers
Sterilization
of infected
root canals
Endosurgery

66. PULP
VITALITY – Laser used - Nd:YAG at 2W, 20
pulses per sec (pps) at
distance of 10mm from the
tooth surface

67. INDIRECT
PULP
CAPPING
• In cases of deep and
hypersensitive cavities
• A reduction in the permeability of
the dentin- achieved by sealing
the dentinal tubules
• Lasers used
– Nd: YAG – 2W & 20 PPS for
less than one sec with black
ink
– CO2 laser

68. DIRECT
PULP
CAPPING
laser treatment causes successful
pulp restoration after direct capping
of inflamed pulps with laser
irradiation
• 1 or 2 W laser energy after
alternate irrigation with 5.25%
NaOCl and 3% Hydroen peroxide
• Exposure site closed with Calcium
hydroxide paste
• Nd: YAG, Argon laser, Diode laser,
Er: YAG, CO2 laser

69. PULPOTOMY
& VITAL
PULP
AMPUTATION
• One of the most anticipated laser
treatment in Endodontics
• Lasers used –
– CO2 laser 1 to 4 W
– Nd:YAG for 2sec,
• Carbanized layer that is formed
on the surface must be removed
with 3%hydrozen peroxide and
5.25% of NaOCl

70. PULPECTOMY
AND ROOT
CANAL WALL
PREPARATION
• Access cavity preparation
Er:YAG – 8Hz, 2W
• Pulpectomy
• Nd:YAG for 2W at 20 PPs for one sec,
Multiple application with 5 sec
interval
• Cleaning and shaping
– CO2 laser
– Nd:YAG laser
– Argon lasers
– Er:YAG- most effective
• Limitations of lasers in cleaning and
shaping
• The laser energy from the tip is
directed along the root canal and not
necessarily laterally to the root canal
wall.
• Thermal damage to the periapical
tissues

71. STERILIZATION
OF INFECTED
ROOT CANALS
• Effective tools for killing
micro-organisms by its
bactericidal effect
• Lasers used
• Nd:YAG laser 100mJ for 5
sec, twice
• Diode lasers- 150mJ for 5
sec, twice
• Er:YAG laser- 75mJ for 5
sec, twice
• Argon lasers
• CO2 lasers

72. OBTURATION
OF ROOT
CANALS
• Obturation with AH –plus and
composite resin activated by
Argon lasers
• Laser initiates photo
polymerization by activation of
composite resin
• Argon laser, CO2 laser, Nd:YAG-
soften the guttapercha – vertical
compaction
• Argon lasers – good apical seal

73. RETROGRADE
CAVITY
PREPARATION
& ENDODONTIC
SURGERY
Apicosectomy
Er:YAG laser – 200mJ for
root resection

74. TOOTH
WHITENING
• Nd:YAG & DIODE laser can be use
74

75. RECONTOURING
OF GINGIVAL
MARGINS FOR
CROWN
LENGHENING
75

76. WHICH ONE IS BEST???
DIODE LASER CO2 LASER

77. DIODE LASER
Compact weighing less than 10
Ibs, ease of use & portability
Can be move to the other areas
quickly & easily
Can be used with contact
method the same way that a
metal scalpel is used
Non contact method will not cut
the tissue because the diode
light goes through the skin
surface to treat pain,
inflammation and wound
CO2 laser
Co2 laser weigh over
40 Ibs
Larger and Heavier
Use only a Non
contact method
Using a co2 laser
requires skills to
focus the laser on
specific point

78. DIODE LASER
Can incise vessels of 1 to
2mm in diameter with
little or no bleeding.
This superior hemostatic
ability reduces the overall
risks of surgery
Diode laser can be used
for endoscopic surgery
Cost: 3.25 lakh/ piece
CO2 laser
CO2 laser tends to be
absorbed by water, This
means that is very difficult
to stop bleeding
It is possible to incise
capillaries without bleeding
but it is difficult to incise
vessels of 1 mm or larger
without bleeding
CO2 laser can not be
used for endoscopic
surgery

79. 1. A Clinical guide on oral laser applications, Anil shah, Naresh thukral,
Mohan vakade
2. Sunil r panat, Gv sowmya,astha durgvanshi,Laser in oral medicine: an
update,Jp-journals-10039-1045
3. Reshma j abraham, arathy s lankupalli, Laser management of intraoral soft
tissue lesions,IOSR journal of dental and medical sciences, Volume 13, PP
59-64( feb 2014)
4. Sanjeev kumar, Sandhya maheshwari, Laser in dentistry: an innovative tool
in modern dental practice,Nati J Maxillofac Suurg.2012 jul-dec
5. Carbon Dioxide Laser Guidelines, DS Krupa Shankar, M Chakravarthi, J
Cutan Aesthet Surg. 2009 Jul-Dec; 2(2): 72–80.
6. Donand j. coluzzi, Portola vally, Fundamentals of laser in dentistry, J laser
Dent 2008,16 (sep issue):4-10
7. Dr resmi, dr Nandakumar, The current status of low level laser in dentistry,
JIDA,2002, vol 73,198-202
REFERENCES