Light is an integral part of our life. Advances in technology are increasing and changing the ways that the patient experience dental treatment. One of the milestones in technological advancements in dentistry is the use of lasers The early 20th century saw one of the greatest inventions in science & technology, in that LASERS which later went on to became a gift to health sciences. Albert Einstein is usually credited for the development of the laser theory. He was the first one to coin the term “Stimulated Emission” in his publication “Zur Quantentheorie der Strahlung”, published in 1917 in the “Physikalische Zeitschrift” Lasers are devices that produce beams of coherent and very high intensity light. The word LASER is an acronym for “Light Amplification by Stimulated\Emission of Radiation”. A crystal or gas is excited to emit light photons of a characteristic wavelength that are amplified and filtered to make a coherent light beam. The effect of the laser depends upon the power of the beam and the extent to which the beam absorbed. Several types of lasers are available based on the wavelengths. These range from long wavelengths (infrared), to visible wavelengths, to short wavelengths (ultraviolet), to special ultraviolet lasers called excimers. Lasers are used nowadays in many areas in the field of dentistry It is of the most captivating technologies in dental practice. Even though, introduced as an alternative to the traditional halogen curing light, laser now has become the instrument of choice, in many dental applications. Its advancements in the field of dentistry are playing a major role in patient care and well being.

1. LASERSINORALSURGERYANDPROSTHODONTICS
Dr. SANCHAYITA ROY & Dr. RON DUTTA

2. • INTRODUCTION
• HISTORY
• LASER PHYSICS
• LASER COMPARTMENT AND DELIVERY SYSTEM
• LASERCLASSIFICATION
• LASER EFFECTS ON TISSUE
• MOST COMMON LASERS IN DENTISTRY
• LASER APPLICATION IN PROSTHODONTICS
• LASERS IN RPD, CD, FPD, ESTHETICS, IMPLANT,
MAXILLOFACIAL PROSTHESIS, DENTAL MATERIALS, USE IN
LABORATORY
• LASER IN ORAL SURGERY
• LASER IN DIAGNOSIS
• DENTAL LASERS IN FUTURE
• LASER SAFETY
• REFERENCES
CONTENTS

3. INTRODUCTION
• LASER = “light amplification by stimulated
emission of radiation”
• Lasers are devices that produce beams of coherent and very
high intensity light.
• An alternative to traditional halogen curing light, laser now
has become the instrument of choice, in many dental
applications.
• Its advancements in the field of dentistry are playing a major
role in patient care and well being

4. HISTORY
ALBERT EINSTEIN 1915, Neils Bohr’s atomic model --
basis for quantum mechanics and,
useful in demonstrating laser
principles
Einstein credited with development of
Laser theory. Coin the term “Stimulated
Emission” in his publication “Zur
Quantentheorie der Strahlung”,
published in 1917.

5. CHARLES H TOWNES (1951)
Charles Hard Townes, an
American physicist invented
the MASER
(Microwave Amplification
by Stimulated Emission of
Radiation)

6. THEODORE H
MAIMAN (1960)
Maiman introduced first Laser using
synthetic ruby rod (RUBY LASER)
Lasers as bloodless surgical tool for T/t
of cancers & as dental equipment .
1956,--exposed extracted tooth to
prototype Ruby (694 nm) Laser, ---
transmission of Laser energy was
found.
The first actual laser, based on a pink
ruby crystal, was demonstrated in 1960
by at Hughes Research Laboratories.

7. LEON GOLDMAN(1965)
Goldman established the first
laser medical laboratory using
ruby laser.
1960, Goldman and Polanyi and
Jako developed Nd:YAG, CO2
lasers for surgery of oral cavity
THE FATHER OF LASER
MEDICINE

8. • In 1965 Taylor reported the histologic effect of ruby laser on the
dental pulp.
• The 1st application of LASER in maxillofacial surgery was by Lenz
et al in 1977, who used argon laser to create a nasoantral window.
• CO2 laser was 1st invented by Kumar Patel in 1964 and it was 1st
applied to periodontal surgery by Pick in 1985.
• In 1996, Use of lasers on hard tissue such as teeth or the bone of
the mandible
•
• In 1997, laser armamentarium has been designed
• 1997 - FDA gave clearance for first true dental hard tissue
Er:YAG laser and the Er,Cr:YSGG a year later.

9. Light is a form of an electromagnetic energy which is basically
waves of energy that has both electric and magnetic field
component which are perpendicular to each other.
Light consists of photons — “particles” with no mass which travel
at the speed of light.

10. Long wavelength
Low frequency
Low energy
Short wavelength
High frequency
High energy
Non ionizing Ionizing

11. Electromagnetic radiation in this range of wavelengths is called visible
light or simply light. A typical human eye will respond to wavelengths
from about 390 to 700 nm

12. LASER PHYSICS

14. Energy of these atoms in excited states is provided externally by some energy source
referred to as the “pump” source.
Amplification by stimulated emission

15. Probability for an atom to absorb
photon is same as probability for an
excited atom to emit a photon via
stimulated emission,
The collection of real atoms will be a
net absorber, not a net emitter, and
amplification will not be possible.
Hence , to make a laser, we have to
create a “population inversion

16. Population inversion -- amplify a signal via stimulated emission,
Most of the excited atoms in population emit spontaneously and do not
contribute to the overall output
A resonator = a system of mirrors that reflects undesirable (off-axis) photons
out of the system and reflects the desirable (on-axis) photons back into the
excited population where they can continue to be amplified.
•Lasing medium is pumped
continuously --- create a population
inversion at lasing wavelength
• Photons travel on- axis and off-axis
•Photons on- axis will be reflected
back into lasing medium & stimulate
more excited atoms.

17. •Active medium
•Pumping
Mechanism
•Optical resonator
•Cooling system
•Control Panel
•Delivery system
LASER COMPARTMENT

18. Arthur Shawlow said, “Hit it hard enough and anything will lase.

19. •(with mirrors at joints) –
UV, visible & infrared lasers
•(flexible tube with reflecting
internal surfaces) – middle &
far infrared lasers.
•Fiber optics – visible & near
infrared lasers
LASER DELIVERY SYSTEM

21. FOCUSED DE-FOCUSED
• Laser beam hits
tissue at its focal
point- narrowest
diameter
• Beam moved away
from its focal point
• Cutting mode • Wider area of tissue
affected as beam
• Ablative mode
• Low level laser
therapy
LASER OPERATION PARAMETERS

22. CONTACT NON-CONTACT
• Tip is in contact with
tissue
• Tip is kept 0.5 to 1
mm away from tissue
• Concentrated
delivery of laser
energy
• Laser energy
delivered at the
surface is reduced
• Char tissue
formation at tip
• Tactile feedback is
available

23. Basic modes of wavelength emission for dental lasers:
Continuous wave emission: laser energy is emitted
continuously produces constant tissue interaction.
Equipped with a mechanical shutter with a time circuit to
produce gated or super-pulsed energy to minimize some of
undesirable residual thermal damage.
Eg. CO2, Ar, and diode lasers
Free-running pulse emission: very short bursts of laser
It provides target tissue with thermal relaxation time to cool.
Eg. Nd:YAG, Er:YAG, and Er,Cr:YSGG

24. LASERS CHARACTERISTICS
Monochromatic
Coherent
Unidirectional
Collimated
Efficacy
Laser beam= Single wavelength
(visible or infrared)
•Photon beams have same frequency
•Waves are identical & phased
• Constant phase relationship with
time and phase ---COHERENT
Perfectly parallel to directional
light
at very low average power levels
lasers can produce required
energy to perform specific fn.

26. CLASSIFICATION
1. According to wavelength:

28. 2.Based on the penetration power of the beam:
• Hard tissue lasers: Erbium lasers.
• Soft tissue lasers: Diode, Nd:YAG,CO2 laser.
3.Based on the emission mode:
• Continuous wave
• Gated pulse
• Free running pulsed

29. 4.Based on the laser material used:
• Gas lasers: CO2, Argon, He-Ne lasers
• Liquid lasers: Dye lasers
• Solid state lasers: Ruby , Nd:YAG lasers
• Semiconductors: Gallium, Arsenide (diode laser).

30. 5. According to ANSI & OHSA standards
Class I : Low powered lasers that are safe to use.
Class IIa : Low powered visible , hazardous only when viewed
directly for longer than 1000 seconds.
Class IIb : Low powered visible , hazardous when viewed for
more than 0.25 seconds.
Class IIIa : Medium powered ,hazardous if viewed for less than
0.25 seconds without magnifying optics.
Class IIIb : Medium powered, hazardous when viewed directly.
Class IV : High powered lasers, that produce ocular skin and
fire hazards.

31. LASER EFFECT ON TISSUES
Incident light energy will interact with a medium (eg oral tissue) that is denser
than air, in one of four ways
≥50% back-scatter

32. Laser absorption characteristics:
Laser emission mode: continuous beam, or forms of pulses with time
Laser incident power (Joules per second)
Laser power density (Watts per square centimetre):
smaller the beam diameter, greater concentration of heat effects.
Beam movement: relative to tissue site;
rapid laser beam movement --- reduce heat build-up ----thermal relaxation.
Endogenous coolant: blood flow.
Exogenous coolant: water, air, pre-cooling of tissue
SECONDARY FACTORS ARE:
•Laser wavelength
• Tissue (composition) and thickness • Surface wetness
• Incident angle of beam, • Exposure time • Contact vs non-contact mode

33. LASER EFFECTS ARE DUE TO
Depending on the time of irradiation
and the power density,
photochemical
Biostimulation &
Photodynamic therapy
Clinical application in dentistry are:
low level laser therapy (LLLT) &
photodynamic therapy (PDT).
 photo-thermal
Photopyrolysis , photovaporolysis
photoplasmolysis
 photo-mechanical
Photodisruption & Photoacoustic

34.  Photochemical effect:
Biostimulation
PDT: Association of a certain wavelength and a specific chromophore
able to absorb the light. Tissue response in terms of change of covalent str
LLLT: (Endre Meister in 1967) ---pain reduction & fast healing process
• Work towards healing by stimulation of factors &
processes, Below surgical threshold
• Useful for pain relief, increased collagen growth &
anti-inflammatory activity
Photopyrolysis
Photovaporolysis
Photoplasmolysis
Ascendent heat levels-phase transfer , liquid to vapor at
100 deg C
Tissue removed by formation of electrically charged
ions and particles in a semi-gaseous high energy state.
Ascending temperature change from 60oC to 90oC,
target tissue proteins undergo permanent
morphologic change.
Photothermal effect:

36. • When rapid pulses of light are incident ,they can be absorbed and
resulting energy radiated as heat.
• This heat causes detectable sound waves due to pressure variation
in the surrounding medium.
Photoacoustic: conversion between light and acoustic waves due
to absorption and localized thermal excitation
PHOTOMECHANICAL
Disruption of tissue due to a range of phenomena,
including such as Shock wave formation, Cavitations etc
Action:
• photoablation----fast thermal explosion & mechanical shock waves
• photodisruption ----nonlinear tissue behavior , optical breakdown &
mechanical shock waves

37. HARD AND SOFT TISSUE LASER
‘Hard’ and ‘soft’ based on their effect on tissue (not relate to
target tissue types)
• ‘Hard’, or surgical lasers---- high power lasers
direct interaction. (photothermal)
incident light energy is absorbed and converted into thermal
energy which causes tissue change.
• ‘Soft’, or ‘low-level’ lasers -----low power lasers
an indirect interaction (photobiostimulation)
eg. tissue warming, increase of local blood flow and
production of endorphins. Eg. HeNe , GaAlAs diode, GaAs
diode , defocused Co2 & Nd:YAG laser , Argon ,

39. - Laser soft tissue surgery (Nd:YAG) well accepted by child patients.
BDJ, VOL 187, 1999

40. The depth and extent differ with laser wavelength,
superficial with longer wavelengths---less oedema
Deeper with shorter wavelength ----greater oedema
central zone of tissue ablation Irreversible protein
denaturation
(coagulation, eschar)
Reversible, reactionary
Along thermal gradient

41. SOFT TISSUE
• Cut, coagulate, ablate or vaporize target tissue elements
• Sealing of small blood vessels
• Sealing of small lymphatic vessels
• Sterilizing of tissue- Eschar
• Decreased post-operative tissue shrinkage
BENEFITS OF LASER – TISSUE INTERACTION
In dental hard tissue the water component is vapourized at 100 °c and the
resulting jet of steam expands and then explodes the surrounding matter
into small particles. This micro-explosion of the apatite crystal is termed
SPALLATION

42. Effects of long wavelength laser light on hard dental tissue:
Explosive vaporisation of water
content of enamel & dentine,
• Dissociation of tissue and
ejection of micro-fragments
Er:YAG
Er,Cr:YSGG
Co2
Affinity for ----
Hydroxyappatite
Water chromophores

43. WHAT DOES THE OPERATOR CONTROL?

44. CO2 LASER
LASER CHARACTERISTICS
WAVELENGTH 9300, 9600, 10600 nm
ACTIVE MEDIUM Carbon dioxide gas
DELIVERY SYSTEM Articulated arm
MODE OF OPERATION Continuous wave, gated pulsed
mode.
Used in focused and de-focused
modes
CHROMOPHORE Water, hydroxyapatite
LIMITATION High risk of carbonisation
ADVANTAGE Carbonized /charred layer acts as
biological dressing

45. ARGON LASER
LASER CHARACTERISTICS
WAVELENGTH 488 – 514 nm
ACTIVE MEDIUM Argon gas
DELIVERY SYSTEM Optical fiber
FIBER DIAMETER 300 microns
MODE OF OPERATION Continuous wave
CHROMOPHORE Melanin pigment,
haemoglobin,
hemosiderin
APPLICATIONS Soft tissue only
Pocket debridement and de-
epithelialisation for GTR

46. DIODE LASER
LASER CHARACTERISTICS
WAVELENGTH 810 – 980 nm
ACTIVE MEDIUM Semi-conductor diode
DELIVERY SYSTEM Optical fiber- quartz or silica
FIBER DIAMETER 300 microns
MODE OF OPERATION Continuous wave, gated pulse mode
Used in focused and de –focused
modes
CHROMOPHORE Melanin pigment, haemoglobin
APPLICATIONS Primarily soft tissue applications- all
minor surgical procedures

47. ND:YAG LASER
(neodymium-doped yttrium aluminium garnet)
LASER CHARACTERISTICS
WAVELENGTH 1064 nm
ACTIVE MEDIUM Neodymium in YAG crystal
DELIVERY SYSTEM Optical fiber
FIBER DIAMETER 300 microns
MODE OF OPERATION Continuous wave, pulsed wave
CHROMOPHORE Melanin pigment,
haemoglobin, water
APPLICATIONS Soft and hard tissue,
Causes more thermal damage

48. LASER CHARACTERISTICS
WAVELENGTH 2940 and 2780 nm
ACTIVE MEDIUM Erbium ion embedded in
YAG or YSGG crystal
DELIVERY SYSTEM Articulated arm, hollow wave
guide,
FIBER DIAMETER Tip diameter – 0.6mm
MODE OF OPERATION Continuous wave, free running
pulsed mode. Used in focused
and de- focused modes.
CHROMOPHORE Water, hydroxyapatite
Er:YAG LASER
(erbium-doped yttrium aluminium garnet

49. Er,Cr:YSGG (2790 nm) --- active medium of a solid crystal of
yttrium – scandium-gallium-garnet doped with erbium and
chromium.
Er:YAG (2940 nm) -----active medium of a solid crystal of yttrium-Al-
Garnet doped with erbium.
CHROMOPHORE: water & hydroxyapatite
USES:
• Caries removal and tooth preparation used with a water spray.
•Healthy enamel surface can be modified for increased adhesion
Er,Cr: YSGG & Er:YAG LASER

51. All dental soft tissue surgeries can be performed by soft tissue laser
(LLLT), but the erbium (Er) family of lasers is the only group of
lasers indicated for treatment of osseous tissue.
Benefit of laser in prosthetic surgeries:
1. reduces bacteria at the surgical site
2. coagulates blood vessels.
3. minimizes scar formation.
4. reduces swelling and postoperative pain.
5. facilitates the overall treatment of prosthodontic patients.
LASER IN PROSTHODONTICS

52. •Tuberosity , Torus / exostosis reduction
•Soft tissue and residual ridge modification
•Epulis fissuratum reduction
•Denture stomatitis
•Treatment of flabby ridges
•Vestibuloplasty
•frenectomies
•Osseoectomy during tooth/root extraction or ridge contouring
•Treatment of soft tissue and hard tissue undercuts.
•Laser welding (Nd:YAG ) for Ni-Cr-Mo & Cr-Co-Mo alloys
laser welding, 20%-50% higher values of tensile strength compared with
soldering.
LASER IN RPD

53. Immediate postoperative views of the maxilla (c) following frenectomy and
vistibuloplasty and the mandible (d) following vistibuloplasty.

54. •Crown lengthening & Osseous lengthening (Erbium lasers )
•Soft tissue management around abutments ( Argon)
•Troughing (Nd:YAG. replace need for retraction cord, electrocautery)
•Formation of ovate pontic sites (Co2 laser)
•Bleaching (Er:YAG and Er Cr:YSGG )
•Veneer removal (Er:YAG and Er Cr:YSGG )
•Tooth preparation (Er, Cr: YSGG )
•Removal of the carious lesion and cavity preparation. (Er: YAG laser – 1997)
•Direct Fiber reinforced composite restoration (Er: YAG lasers -----
thermomechanical ablation by microexplosions of smear layer)
•De-pigmentation of gingiva. (Diode, Nd:YAG, CO2 and erbium )
• Laser phototherapy (AsGaAl)
•Dentinal hypersensitivity. (soft tissue laser and Er family)
LASER IN FPD

56. Laser Specification Treatment
effectively
MOA
He-Ne
Senda et al. (1985).
pulsed (5 Hz)
CW mode
5.2 to 100%. increases the action
potential of nerve
Ga- Al-As diode-
Matsumoto et
al.(1985).
CW for 0.5- 3
Minutes.
85-100% blocking the depolarization
of C-fiber afferents.
(Wakabayashi et al.1992-
1993)
Nd:YAG -
Matsumoto et al
(1985)
black ink as absorption
enhancer , prevent any deep
penetration into E/D/P
Co2
Moritz et al.(1996).
1W for 5-10sec dentinal desiccation for
temporary clinical relief
(Fayad et al.1996).
Er:YAG deposition of insoluble salts
in the exposed dentinal
tubules.
Er, Cr: YSGG 0.5W for 30s thermo mechanical process

57. Laser handpiece: High-speed hand piece with fiber-optic tips instead of bur,
Focal point approximately 1-2 mm
Crown preparation
Cutting enamel (6W,90% air,75% water), defocused mode for 30 sec- 1 min
Placing gingival margin –(1.25 W, 50% air, 40% water )-- accuracy.
Interproximal, buccal, lingual/palatal reduction --- ( 4W, 65% air, 55% water)
 Finish Buccal cusp overlay and final margination ----( 2.25 W, 65% air, 55% )
Advantages:
No anesthesis reqd. --- temporary paresthasia
Accurate and faster
Disadvantages: Trained dentist required for use.
CROWN PREPERATION
Hydrokinetic technology (laser-energized water to cut /ablate tissue)

58. EXCIMER LASER (308nm)
one laser that offers precise ablation of tissues, fiber delivery, bactericidal effects,
good transmission through water and enamel surface conditioning in one system.
Very expensive and time consuming • Used for RCT

59. Gently washes away decay with laser-
energized water droplets

60. Laser phototherapy:
LLLT eg AsGaAl (gallium aluminum
arsenide) 660 nm laser
Promote soft tissue bio-modulation around
prepared crown to ensure no inflammation
signals is present in gingival tissue before
final luting procedure
Lasers: Argon, CO2, diode, erbium, and pulsed Nd:YAG
LASER IN ESTHETICS
Smile designing

61. i) Prototyping and CAD/CAM technology.
Titanium plate for CD: CAD/CAM + LRF (Laser Rapid Forming)
Laser scanner, reverse engineering software, and STL .
Denture plate built layer-by-layer, on LRF system
ii) Analysis of occlusion by CAD/CAM.
laser scanner technique and 3D reconstruction in balanced cases.
iii) Analysis of accuracy of impression by laser scanner.
Scanning laser (3D) digitizer.
It accurately and reliably measure dimensions of dental
impression materials while avoiding subjective errors.
LASER IN CD
Lasers in prosthodontics – a review. Journal of Evolution of Medical and Dental
Sciences/Volume1/ Issue4/October - 2012

62.  Socket sterilization & Implant site preparation
Peri implantitis ( to vaporise any granulation tissue - Diode laser,
CO2 laser and Er:YAG )
Preoperative frenectomy and tissue ablation
 Debridement of implant surface (Er: Cr: YSGG ---2780 nm –
uses ablative hydrokinetic process for decontamination & debridment)
Second stage uncovering of implant (CO2 laser )
Repair of ailing implant.
LLLT eg. diode soft laser (690 nm) used on contaminated surface for
60 sec after placement of toluidine blue O for 1 min. Reduced bacteria
count by 92%.
LASER IN IMPLANTOLOGY
Gounder R, Gounder S. Laser science and its applications in prosthetic rehabilitation. J Lasers Med Sci.
2016;7(4):209-213.

64. 3D Printing:
3D printing for both bony & soft tissue reconstruction,
a model obtained from (CAD) & built in a layer by layer fashion.
Various 3D printing techniques :
•stereolithography,
• multijet modelling,
•SLS,
•binder jetting ,
•fused deposition modelling.
LASER IN MAXILLOFACIAL
PROSTHESIS
Gounder R, Gounder S. Laser science and its applications in prosthetic rehabilitation. J Lasers Med Sci.
2016;7(4):209-213.

65. 1 .Laser cutting
2. Laser welding
3. Fabrication of prosthesis using CAD-CAM, DLMS, rapid
prototyping etc.
4. Laser titanium sintering
5.Laser ablation of titanium surfaces
6.Laser-assisted HA coating
7.Laser welding of titanium components of prostheses.
Lasers have (pulsed) for deposition of HA thin films on titanium implants.
Also for surface treatment of titanium castings for ceramic bonding
LASER IN LABORATORY

66. Laser microgroove implant—
LASER LOK

67. Laser welding
It is a union process based on localized fusion in the
joint, through bombardment from a high-intensity,
concentrated, monochromatic and coherent light
beam.
The area to be welded is protected by using an inert
gas, usually argon or a mixture of inert gases.

68. Intraoral welding
Based on creation of an electric arc btw two electrodes under an argon gas flux:
Causing ---inter-digitations of titanium prisms
• 1967 Gordon described the possibility of welding metallic portions
•Initially, CO2 and Nd:YAG used ---- but Nd:YAG gained popularity
(Shinoda et al, 1991- Yamagishi et al, 1993).
•Nd:YAG laser to weld appliances, extra- and intra-orally, in dental office.
Methods: “Syncrystallization” and “Mondani Electrowelder”
•ILW technique is effective on all metals and alloys
•Can be applied either with or without filler metal and shielding gas
•Small spot size of the beam (0.6 mm), restrict high temperature within a very
limited area.
Limitations are:
Effective only on titanium and its alloys,
Cannot be used on patients with pacemaker,
Some energy from welding process spreads to adjacent area (teeth, acrylic,
ceramic, etc.).

69. Intraorally Welded Titanium Bar in
the Immediate Loading Implants

71. Alloy Lasers
Ti and its Alloy CW–CO2, Pulsed Nd:YAG laser,
Fiber laser, Yb:YAG ytterbium
Ceramics CW–CO2, KrF excimer laser,
pulsed YAG
Steel and its alloy Pulsed Nd:YAG, CW-laser,
Photolytic iodine laser, CW–CO2
and diode laser
Al alloy Pulsed Nd:YAG laser, CW–CO2,
Fiber laser
Gold Semiconductor laser, Nd:YAG laser
LASER IN DENTAL MATERIALS

73.  Lasers are rapidly becoming the standard of care for
many procedures performed by oral and
maxillofacial surgeons
 The reason for this transition is due to the fact that
many procedures can be executed more efficiently
and with less morbidity using lasers as compared to
a scalpel, electrocautery or high frequency devices
 Early lasers were bulky and historically used for
major cases in operating theaters; but today, access
to small, portable, office-based lasers with improved
intraoral delivery systems have made it possible to
treat even minor routine procedures in the clinic

74. Advantages
 The advantages of laser surgery include:
 Hemostasis and excellent field visibility
 Precision
 Enhanced infection control and elimination of bacteremia
 Lack of mechanical tissue trauma
 Reduced postoperative pain and edema
 Reduced scarring and tissue shrinkage
 Microsurgical capabilities
 Less instruments at the site of operation
 Asepsis due to non-contact tissue ablation and prevention of
tumor seeding

75. Laser Osteotomy
 Experimental laser osteotomies performed in vitro
and in vivo using different wavelengths including
excimer lasers, Er:YAG, CO2 and Ho:YAG lasers
 The laser light emitted by Er:YAG and CO2 ---
absorbed water
Er:YAG laser--- absorbed by hydroxyapatite
CO2 laser --- absorbed by collagen
 Light microscopy, histologic sections and SEM
revealed no charring, but a very thin basophilic zone
next to the cut surface, while cutting the trabecular
structures resulted in coagulation zone

76. Fibromas
 Fibromas are often due to lip biting.
 The soft tissue surgery can be performed using Laser
HF using the fibroma removal mode (975nm, 5W,
CW) without side effects or complications after
surgery

77. Clinical appearance of a lower lip fibroma
Use of Laser HF for soft tissue
surgery
Postsurgical
view.
Follow up two weeks after
surgery.

78. Mucocele
 Mucoceles of the lip can be unroofed, then excised
with gland tissue using Laser HF, using fibroma
removal mode (975nm, 5W, CW).
 The wound margins may be sealed with a defocused
beam without side effects or complications.
 Re-epithelization takes about three weeks

79. Clinical appearance of the
mucocele
Unroofed lesion after first laser
use
Excision of the lesion together with adjacent salivary gland using diode
laser
Final postoperative
view.

80. Palatal Lesions
 Lesions of the soft palate such as traumatic fibromas
in the soft palate can be treated using Laser HF,
fibroma removal mode (975nm, 5W, CW).
 Application of LLLT immediately after surgery may
expedite healing (Acupuncture mode, 660nm,
90mW, 90s interval) without side effects or
complications

81. Clinical appearance of the fibroma of the soft
palate
Usage of diode laser for soft tissue surgical
procedure
Application of LLLT immediately after
surgery.
Follow up three weeks after
surgery

82. Epulis Fissuratum
 Epulis fissuratum of the jaws can be removed using Laser
HF, via a combination of Fibroma removal (975nm, 5W,
CW) and Gingivectomy modes (975nm, 3W, 10ms, 1:2),
followed by LLLT application immediately after the surgical
procedure (Acupuncture mode, 660nm, 90mW, 90s
interval).
 The aPDT may also be performed (660nm, 50mW, 30s
interval) without complications
 Palatal fibroepithelial polyp and inflammatory papillary
hyperplasia of the hard palate can be treated similarly using
Laser HF using (Fibroma removal mode, 975nm, 5W, CW)
in combination with loop of high frequency.
 LLLT application (Acupuncture mode, 660nm, 90mW,90s
interval) immediately after surgery

83. Clinical appearance of a maxillary epulis
fissuratum
Surgical procedure performed using diode
laser
Immediate postsurgical
view.
Application of the ''photosensitizer'', a coloring solution for aPDT,
and photodynamic therapy using diode laser. b. Application of the
diode laser.

84. Exposure of impacted teeth
 Exposure of an impacted tooth (soft tissue
impaction) can be done using Laser HF,
(Gingivectomy mode, 975nm, 3W, CW).
 After laser incision around the impacted crown, the
mucosal tissue is removed with an elevator until the
underlying crown is identified

85. Clinical view before surgery
Incision using diode
laser.
Removal of the mucosal flap with an elevator.
Immediate application of the orthodontic
element.

86. Crown lengthening
 Crown lengthening is easily done using lasers.
 After raising the mucoperiosteal flap, selective
osteotomy with the surgical bur is performed.
 Subsequent to the suturing and frenectomy, laser
gingivectomy using LaserHF (Gingivectomy mode,
975nm, 3W, 10ms, 1:2) for the lengthening of clinical
crowns can be done

87. a. Treatment planning before surgery. b. Radiograph before surgery.
a. Selective osteotomy after raising the mucoperiosteal flap. b. Selective osteotomy completed.

88. a. Subsequent to the suturing and frenectomy, gingivectomy using
diode laser was performed.b. Frenectomy, gingivectomy completed.

89. Laser Doppler Flowmetry
- To monitor pulpal and gingival blood flow
- To assess tooth vitality
• Laser Fluorescence for detection of caries
• Laser Doppler Vibrometry to measure tooth mobility.
LASER DIAGNOSTICS

90. PART OF EYE
DAMAGED
LASER TYPE
• Corneal damage • Er Cr YSGG, Ho YAG, Er
YAG, CO2
• Lens damage • Diode, Nd YAG, Ho YAG,
Er Cr YSGG, Er
• Aqueous damage • Ho YAG, Er Cr YSGG, Er
YAG
• Retinal damage • Argon, He Ne, diode, Nd
YAG
EYE DAMAGE

91. 315 – 400 nm
Eye Lens Damage
760 – 1400 nm
Retinal Damage
1400 nm – 1 mm
Corneal Damage

92. • Radiation absorbed in eye
lens
• Effects are delayed (e.g.;
cataracts).
Near Ultraviolet
Wavelengths
(315 - 400 nm)
• Radiation transmitted to
retina
• Overexposure --- flash
blindness or retinal burns
and lesions.
Near Infrared
(760 - 1400 nm)
• Radiation transmitted to
cornea.
• Overexposure --corneal
burns.
Far Infrared
(1400 nm -
1 mm)

93. EYE PROTECTION
Eye wear for patient
Safety Glasses

94. PLUME CONTROL
 Rapid rise in temperature causes cells to rupture
 Release of heated plume -- particles, gases (e.g., hydrogen
cyanide, benzene, and formaldehyde), tissue debris, viruses,
and offensive odour
 Also HPV, HIV, coagulase-negative Staphylococcus,
Corynebacterium species, and Neisseria species) detected in
laser plumes
RECOMMENDATION:
 High-filtration surgical masks,
 Central room suction units and
 Mechanical smoke exhaust systems (high volume laser smoke
evacuation)

95. Laser Plume Face Mask
Protection from particle size less than 0.1 micron

96. SHARPS
 Scored laser tips of quartz fibers are considered sharps
and need to be disposed according to standard waste
disposal protocols

97. WARNING SIGNS

98. HOW TO MINIMIZE LASER HAZARD
Engineering Control
• Automatic features in built with the system to
protect personals – Warning System, Interlock
Administrative Control
• Policies that limit exposure to laser hazards – Only
for Authorized Personals
Procedural Control
• Standard Operating Procedure to be followed while
working with lasers
Beam Control
• The use of beam blocks, beam tubes etc to
minimize the Nominal Hazard Zone

99. LASER WARNING
SYSTEM
LASER CONNECTED
INTERLOCK

100. FIRE & EXPLOSION HAZARD
Class IV Lasers are associated with fire hazards
Following things must always be kept in mind
while operating such systems:
• Wet or fire-retardant materials - in operative field
• Use only non- combustible anesthetic agent
• Nitrous Oxide supports combustion and should not be
used
• Avoid cleaning the tip with alcohol/spirit . Moistened
gauze to be used just prior to firing
• Store highly combustible or explosive materials outside
• Know location and operation of the nearest fire
extinguisher

101. LASER IN FUTURE
1. Laser tooth brush : Low level laser therapy (LLLT) can be used to treat
dentinal hypersensitivity

102. 2. Photobiomodulation laser treatment ---
accelerates healing time and reduces inflammation.
Also can be used in treatment of herpes lesions if virus detected early.
3. Nightlase laser therapy----
reduces snoring, increase airway space, enhance quality of sleep.
4. Smoothlase laser therapy (Stealth Facelift) ----
Cosmetic enhancement of face skin using dual laser energy.
Skins around mouth, nose ,chin and upper neck is tightened for youthful
appearance.

103. References
•Gounder R, Gounder S. Laser science and its applications in prosthetic
rehabilitation. J Lasers Med Sci. 2016;7(4):209-213. doi:10.15171/jlms.2016.37.
•Durrani S. Laser and it’s Application in Prosthetic Dentistry. Int J Dent Med Res
2015;1(6):183-188.
•S, Misra SK, Chopra D, Sharma P. Enlightening the path of dentistry: Lasers – A
brief review. Indian J Dent Sci 2018;10:184-9.
•Sandesh Gosawi, Sanajay Kumar et all. Lasers in prosthodontics- a review.
Journal of Evolution of Medical and Dental Sciences 2012; 1(4): 624-33.
•El khourani Wadie and Pr Amal El yamani. “Lasers in Fixed Prosthodontics”.
Acta Scientific Dental Sciences 3.12 (2019): 99-103.

104. •Das Manjula et all. Lasers in Prosthodontics – Review. University J Dent Scie 2017;
3(2) : 09-12.
• LJ Walsh . The current status of laser in Dentistry. Australian Dental Journal 2003
; 48 : (3) 146-155
• Laser in Dentistry, Leo J.Miserendino/Robert M.pick, 1995
• Laser in dentistry: Dental clinic of North America Vol.44,no. 4 Oct. 2000
•Kaura S, Wangoo A, Singh R, Kaur S. Lasers in prosthodontics. Saint Int Dent J
2015;1:11-5
•Dental clinics of North America “ Lasers in Clinical dentistry”. Oct 2004. Vol 48.
Issue 4
•Introduction to laser technology. –online access.
• Fornaini C. Intraoral laser welding. INTECH Open Access Publisher; 2010 Aug 17.

105. We must accept finite disappointment,
but never Lose infinite HOPE.
Dr. Martin Luther King, Jr.
THANK YOU