2. INTRODUCTION
• Laser is acronym for LIGHT AMPLIFICATION BY STIMULATED EMISSION OF
RADIATION.
• Laser energy is base on concept of albert Einstein quantum theory of radiation
hypothesis.
• Lasers are widely used in dentistry for various clinical procedures like cavity
preparation, surgical procedures, scaling and root planning etc. Since its first use
in 1960, lasers are now evolved to be used in all aspects of dentistry.
• THEODORE H.MAIMAN built the first laser (synthetic red ruby) at HUGHES
AIRCRAFT RESEARCH LABORATORY.
3. QUANTUM THEORY OF RADIATION
HYPOTHESIS(1917)
ACTIVATED ELECTRON OF ATOM
return
LOWER STATE
releases
ELECTROMAGNETIC ENERGY
forms
LIGHT/PHOTON
4. HISTORY
•Albert Einstein – 1917 – Quantum theory
•Theodore Maiman – 1960 – 1st Laser using Ruby crystal
•Javan – 1961 – HeNe Continuous mode of laser
•Johnson – 1961 – Nd:YAG Laser
•Leon Goldman – 1963 – Father of modern lasers
•Patel – 1964 – CO2 Laser
5. COMPONENT OF LASER SYSTEM
• Active medium
• Pumping /excitation mechanism
• Optical resonator
• Laser delivery system
• Cooling system
• Control panel
6. ACTIVE/LASER MEDIUM
• Consist of solid, liquid ,gas which is enclosed
in laser cavity.
• Active medium is positioned within laser
cavity within internally polished tubes.
• Active medium defines type of laser and
emission wavelength of laser.
• Atom of active medium are absorbed by
process of light emission.
7. PUMPING MECHANISM
• Source of primary energy that excites active
medium.
• It is usually light source.
• Energy from primary source is absorbed by
active medium resulting in production of laser
light.
• Continuous feed electrical discharge will result
in similar continuous feed of laser light.
8. OPTICAL RESONATOR
• TWO TYPES OF MIRROR
• i)Highly reflected mirror reflect 100% of laser light.
• ii)Partially transmissive mirror reflect less than 100%
light.
• Mirrors are placed parallel to each other and reflect
photons completely at one end.
• Laser light stimulated are bounced back and forth
through axis of laser cavity.
9. LASER DELIVERY SYSTEM
• Depend on use of fixed mirror.
• Fine silica quartz fiberoptic cable maximized feasibility of
medical and dental lasers.
COOLING SYSTEM-
• Heat production is by-product of laser light propogation.
• Increases power output of laser.
10. CONTROL PANEL
• It is variation of power output with time by pumping mechanism.
• It allows wavelength change instrument & print out of delivered
laser energy.
11. GENERATION OF LASER ENERGY
HIGH RADIATION ENERGY IS PUMPED INTO ACTIVE MEDIUM BY PUMP SOURCE
ENERGY IN PUMP SOURCE IS ABSORBED BY ACTIVE MEDIUM
ATOM,IONS AND MOLECULES ARE RAISED TO THEIR UPPER ENERGY STATE
EXCITED EVOLUTION OF ATOM MOLECULES TAKES PLACE WHICH IS CALLED
POPULATION INVERSION
LASER LIGHT GENERATED
12. PHYSICAL PROPERTIES OF LASER
MONOCHROMATICITY-
• Light which is of single colour and wavelength is called monochromatic.
• It is property of laser light to selectively destroy tumour cells.
DIRECTIONALITY-
• Laser light is emitted in narrow beam in specific direction.
• Laser used are unidirectional.
13. COHERENCE-
• Coherence is property of each wavelength is
identical in physical size and shape.
• Laser is allowed to focus on precise point.
• Due to this property laser can deposit lot of
energy within small area.
BRIGHTNESS-
• This property arises from laser light as it moves
through space maintaining its concentration.
15. CHARACTERISTICS OF LASERS
1) ELECTROMAGNETIC SPECTRUM-
• Function of laser is with help of optical spectrum which is portion
of electromagnetic spectrum
• Energy generated in laser beam is positioned within
electromagnetic spectrum and is determined by wavelength &
frequency of light wave.
16. 2.PHOTOBIOLOGY OF LASERS-
• Interaction of non–ionizing EM radiations with biomolecules and resulting in
biologic reaction is known as photobiology.
• In general, lasers have four different interactions with the tissues.
1.Photo-thermal interaction
2.Photo-chemical interaction
3.Photo-mechanical interaction
4.Photo-electrical interaction
17. PHOTO-THERMAL INTERACTION
• This occurs with high powered lasers. The radiant energy absorbed by tissue
substances are transformed into heat energy, which produce the tissue effect.
18. PHOTO-CHEMICAL INTERACTIONS
• The basic principle of photochemical process is that specific wavelengths
of laser light are absorbed by naturally occurring chromophores, which
are able to induce certain biochemical reactions.
• It include effect of lasers on biochemical and molecular process that occur in
tissue such as healing & repair.
19. PHOTO –MECHANICAL INTERACTIONS
• In photo-mechanical effects, the pulse of laser energy on the dental tissues
can produce a shock wave. When this shock wave explodes the tissue, it
creates an abraded crater.
• Breaking of structure takes place by laser light.
20. PHOTO-ELECTRICAL INTERACTIONS
• This includes photo-plasmolysis, which describes how the tissue is
removed through formation of electrically charged ion.
21. LASER INTERACTION WITH ORAL BIOLOGIC
TISSUES
• It was given by DEDERICH IN 1991.
• Biologic factor influence laser tissue interaction are most extensive.
• Optical properties of tissue element determines nature & extent of tissue response
through process of-
• 1. ABSORPTION
• 2.TRANSMISSION
• 3.REFLECTION
• 4.SCATTERING
22. ABSORPTION
• To exert laser energy in tissue it should be first absorbed.
• Amount of energy absorbed depends on
• i)pigmentation ii)water content iii)laser wavelength
iv)emission mode
• CHROMOPHORES are substance in tissue which absorbs
wavelength of light.
• Haemoglobin,pigment melanin absorbs blue wavelength
• In case of dental tissues absorption from lowest to highest
i)enamel ii)dentin iii)bone iv)calculus v)caries vi)soft
tissue(70%)
23. TRANSMISSION
• Transmission through tissue results in no observable laser
tissue reaction.
• Laser energy is passed directly through tissues with no
interaction between incident beam & medium .
• Beam is partially refracted.
• It is highly dependent on wavelength of laser light.
24. REFLECTION
• Beam changes its direction off the surface
producing no effect on target tissues is called
reflection.
• This phenomenon occurs when density of
medium less than refractive angle which
results in total reflection of beam.
25. SCATTER
• Scatter energy is absorbed over broader surface area
or volume of tissues.
• Interaction is present but it is not sufficient to cause
complete decrease in amplitude of beam.
• Scatter will cause reduction of light energy with
distance,with distortion of beam.
• Rays proceed in uncontrolled direction through
medium.
• Back scatter of laser beam can occur when it hits the
tissue.
• It is mostly seen in short wavelength.
26. PHOTOCOAGULATION ACTION OF LASERS
• Photocoagulation appears as whitening of tissue surface.
• Surface change is result of alteration in molecular structure of tissue.
• Lased tissue constricts & vessels also shrinks which result in haemostasis.
BIOLOGIC TISSUES
HEATED
>60 C
COAGULATION
PROTEIN,ENZYME,CYTOKINES & BIOACTIVE MOLECULE HEATED >60C
DENATURATION
27.
28. INDICATIONS OF LASERS
1. BIOPSY PROCEDURE-
Minimal bleeding ,bloodless field,post-op swelling is reduced.
2.LASER VAPORIZATION-
Used to remove large epithelium confined surface lesion.
3.LASER ABLATION-
Use in gingival contouring, hyperplastic lesions.
4.COAGULATION/HAEMOATASIS-
It is obtained by using laser in contraction of collagen of vascular wall of vessel.
5. SURGICAL EXTRACTION OF TEETH-
Flap is raised with use of soft tissue laser & bone removal is done by co2 laser
29. 6.APICETOMY-It not only enables removal of roots but also sterilize root in infected
area.
7.PRE-PROSTHETIC SURGERY-epulis, vestibuloplasty, tuberosity reduction, removal of
tori, correction of ridge abnormalities.
8.FRENECTOMY
9.SIALOLITHOTOMY-Used to incise and expose duct.
10.COSMETIC PROCEDURE-Blepheroplasty,endoscopic brow lift, scar revision,skin
resurfacing.
31. TYPES OF LASER DELIVERY SYSTEM
- Fiber optic delivery system- use optic strands, large made of quartz
-Hollow Fiber- Er: YAG and CO 2 lasers utilize a hollow tube with reflective internal
walls which transmit laser energy along its internal axis.
-Articulated arm delivery system: This delivery system utilizes a progression of
verbalized mirrors associated one to each other, prompting transmission of vitality.
Disadvantage: requires a precise system for alignment of mirrors.
-Handpieces-close contact and non-contact handpiece.
35. • The laser beam spot size can be focused or defocused. Depending on degree of
beam focus, the laser beam spot size can be altered & fluency will change
accordingly .
Effect of distance of laser beam on the spot-size at
target tissue surface
Effect of focused and defocused laser beam on
target tissue
36. CARBON DIOXIDE LASERS
• Developed by Patel in 1964
• Emits light in the invisible mid infrared portion of the spectrum at a wavelength of
10,600 nm.
• Uses a mixture of carbon dioxide, nitrogen, and helium as its medium.
• Excited by a high-voltage electrical current.
• Invisible, a red helium-neon laser is often used in parallel, as an aiming beam.
 Chromophore that absorbs the carbon dioxide wavelength is water.
 The depth of penetration can be as shallow as 0.2 mm, with very little scatter,
reflection or transmission.
 Used ideally for soft tissue incision and ablation, sub-gingival curettage, superficial
lesions and removal of sialoliths.
37. ADVANTAGES OF CO2 LASERS
1. Sterile surgical field, bactericidal, viricidal.
2. Minimal cicatrix formation.
3. Access to difficult areas by reflection.
4. Ability to coagulate, vaporize and incise.
5. Good haemostasis.
6. Reduced local tissue trauma and edema.
7. Precise delivery of energy to diseased tissue.
8. Reduced pain – neuron sealing, decreased pain mediator release.
9. Minimized tumor cell dispersion by lymphatic sealing.
39. ER:YAG LASERS
• Erbium: YAG (Er: YAG) laser
• An active medium of a solid crystal of yttrium aluminium garnet that is doped with
erbium.
• For facial resurfacing
• Incision and ablation of soft tissue.
• The presumed advantage of the Er: YAG laser system is its ability to remove
superficial skin layers.
40. ER CR:YSGG LASERS
• Er,Cr):YSGG (yttrium scandium gallium garnet) laser - (2.780nm).
• Active medium of a solid crystal of yttrium scandium gallium garnet that is
doped with erbium and chromium.
• There is absence of melting, charring and carbonization.
• Absorption in water is two to three times lower than Er:YAG laser
• Thermal effects on the tissue are much higher if not administered correctly.
• The erbium wavelengths have a high empathy for hydroxyapatite and the
highest absorption of water compared to other dental laser wavelengths.
• This is the preferable laser for treatment of dental hard tissue, but also, in
contact mode with special surgical tips, it can be used to cut soft tissues.
41. BENEFITS-
• Bactericidal effects, which can sterilize the area
• Analgesic effect on the target tissues, similar to the Nd:YAG
devices.
• Erbium laser energy applied to bone releases growth factors that
enhance regeneration of bone.
42. ARGON LASERS
• Developed by Bridges in 1964.
• Delivers a green-blue light beam in the 488- or 514-nm range, placed in the
visible spectrum.
• Active medium -argon gas that is energized by a high-current electrical
discharge.
• Because the argon beam is highly absorbed by hemoglobin and melanin, it
has excellent hemostatic capabilities.
• Neither wavelength is well absorbed in dental hard tissues or in water.
43. • THESE LASERS ARE USED IN TREATMENT OF-
• Pigmented lesions
• Vascular anomalies and
• Soft tissue incisions and ablations.
44. ND:YAG LASERS
• Neodymium: Yttrium -Aluminium-Garnet (Nd: YAG)
• Geusic and coworkers in 1964, with wavelength of 1064 nm
• It belongs to invisible near- infrared portion of the electromagnetic spectrum.
• A flashlamp is used as the energy source to activate
• Nd: YAG with a very long pulse duration (90-150µs) penetrates water upto 6mm depth
before it is attenuated to 10% of its original strength.
• Energy is scattered rather than absorbed.
• Used as a contact laser scalpel or ablation tool, with excellent hemostasis and cutting
abilities.
45. EXCELLENT FOR TREATMENT OF-
• Vascular lesions.
• Intraoral and extraoral pigmented lesions.
• Achieving hemostasis.
• Open TMJ arthroplasty.
• Malignant lesion excision.
• Black and blue tattoo pigment removal.
46. HOL:YAG LASER
• The holmium: yttrium-aluminum-garnet (Hol:YAG) laser emits laser light at 2140
nm
• Extensively used in endoscopic orthopedic surgery.
• It is also extensively used in the TMJ for lysis of adhesions and sculpting of
fibrocartilaginous disk tissue.
48. TECHNIQUE FOR INTRAORAL INCISIONAL
BIOPSY
1.PROVIDE LOCAL OR GENERAL ANASTHESIA-
• Block or infiltration should be given deep in tissues
• Superfical injecting in tissue may cause inconsistent tissue cutting.
2.OUTLINE INCISION LINE WITHOUT DEEP PENETRATION-
• Outline biopsy slowly
• 0.3-0.5mm additional biopsy margin should be added to normal
margin to allow lateral zone of necrosis associated with laser
excision.
3.CONNECT THE OUTLINE MARKED-
• Incision is carried to desired depth of biopsy
49. • 4.EXCISE THE SPECIMEN-
• Grasp the specimen using focused mode ,undermine
specimen.
• Surrounding tissue to be protected from laser beam.
5.OBTAIN HAEMOSTASIS IF NECESSARY
6.SUTURE IF REQUIRED-
• In rare cases suturing is required appropriate the
margins.
• Suturing is required for cosmesis,when leaving
wound to granulate can result in unacceptable
cosmetic situation.
50. VAPOURIZATION/ABLATION
• Laser vaporization is an
effective,nonmorbid,inexpensive,quick &
painless method of managing premalignant
lesions.
• Tissue ablation is used when surgeons removes
only surface of target to perform superficial
removal of tissue.
• Haemostatic effect of laser results in decrease
tendency of haematogenous & lymphatic
spread.
53. FIBROMA OF RIGHT CHEEK- Removal of the
lesion using Er: YAG laser
54. LASER IN PER-IMPLANTITIS
• Following lasers have bactericidal mode of action
• CO2
• Diode-, Er:YAG- (erbium-doped: yttrium-aluminum-
garnet)
• Er,Cr:YSGG- (erbium, chromium-doped: yttrium-
scandium-gallium-garnet) lasers
• LANAP® – the laser gum disease treatment – the Laser
Assisted Peri-Implantitis Procedure is designed to
preserve implants and protect the surrounding tissue
from further decay.
57. • The study was compare the effectiveness of low-power laser &
dexamethasone after surgical removal of impacted lower third molars
under local anaesthesia.
• There were 120 healthy patients divided into four groups of 30 each.
Group 1 received LPL irradiation immediately after operation, group 2
also received i.m. injection of 4 mg dexamethasone into the medial
pterygoid muscle group 3 received LPL irradiation supplemented by
systemic dexamethasone 4 mg i.m. in the deltoid region, followed by
4 mg of dexamethasone intraorally 6 h postoperatively; and the fourth
(control) group received only the usual postoperative
recommendations (cold packs, soft diet, etc.).
• LPL irradiation with local use of dexamethasone (group 2) resulted in a
statistically significant reduction of postoperative oedema in
comparison to the other groups.
2006 International Association of Oral and Maxillofacial Surgeons
58. ADVANTAGES OF LASERS
• Lasers incise tissue more efficiently than a scalpel as they provide the added
advantages of sterilization of the field of operation, decrease mechanical trauma by
a contact-free incision and minimizes postoperative swelling, pain, and scarring.
• Effectively coagulates blood vessels in the field of operation thereby maintaining a
bloodless field.
• Increased precision and accuracy in surgical procedures due to it ablative properties
and effective control on the depth of penetration of the laser beam.
• Histologically, the wound shows less wound contracture and scarring due to reduced
myofibroblasts.
• Better healing as compared to scalpel.
Journal of Dental and Allied Sciences ¦ Volume 6 ¦ Issue 1 ¦ January-June 2017
59. DISADVANTAGES OF LASERS
• The speed of healing may be delayed.
• Incidence of increased pain 4–7 days postoperatively.
• Laser plume generated during the procedure may be harmful to the persons in the
operating room.
• Scattered and reflected laser beams pose a massive health hazard to the operator,
assistants and patients.
• High cost and operator training.
Journal of Dental and Allied Sciences ¦ Volume 6 ¦ Issue 1 ¦ January-June 2017
60. COMPLICATIONS OF LASERS
• Post-operative infections.
• Post-operative pain.
• Contact dermatitis.
• Promotion of malignant transformation by laser energy.
• Injury to staff.
61. LASER SAFETY
• Laser can cause very high risk causing severe injury & damage.
• Mostly skin and eyes are affected.
• In case of eye it can damage retina,cornea and lens.
• Slight carelessness can destroy vision permanently.
• Skin requires 5-20 watts to cause burn injury.
• Retina may require 2-3 milliwatt to create permanent visual field
loss.
62. OPERATING ROOM SAFETY
PATIENT SAFETY-
• Use of non-inflammable materials wherever possible.
• Use of eyeshield for patients.
• Use of laser resistant shielding material for surgical field for protecting anesthesia
equipment.
PERSONAL SAFETY-
• Eyeshield should be worn by dentist, assistant,patient.
• Safety shield should be used
• Bucket of sterile water should be easily available in operating theatre.
• Laser safety officer must be stationed at laser unit everytime.
• Safety orientation for laser use should be required of all surgeon,anesthesia &
operating room staff.
63. PRECAUTIONS TO BE TAKEN TO AVOID FIRE HAZARD-
• Use of wet cloth or fire retardant drapes.
• No paper and plastic drapes.
• Use of non combustible anasthetics.
• Avoid alcohol moistened guaze while firing laser.
• Protect tissue adjacent to surgical site.
• Know location & operation of nearest fire extinguisher.
• Nitrous oxide should be avoided as it supports combustion and should not be used
during laser surgery.
64. REFERENCES
• TEXTBOOK OF OPERATIVE ORAL SURGERY-LANGDON
• FONSECA ORAL AND MAXILLOFACIAL SURGERY.
• LASERS IN OMFS-LEWIS CLAYMAN
• TEXTBOOK OF ORAL SURGERY-NEELIMA MALIK
• EVOLUTION &APPLICATION OF LASERS IN OMFS-JOURNAL OF
DENTAL & ALLIED SCIENCE 2017
• LASER & TISSUE INTERACTIONS-CLINICS OF NORTH AMERICA 2004
• INTAROARAL LASER SURGERY-CLINICS OF NORTH AMERICA 2004
• COMPLICATIONS OF LASERS IN ORAL SURGERY-CLINICS OF NORTH
AMERICA 2004
• INTERNET
CHROMOPHORES are substance in tissue which absorbs wavelength of light.
ADD CHART FROM NM
cicatrix –scar of healed wound.
ADD PHOTO
Lanap- laser assisted new attachment procedure
Low power lsaers-LLLT works through photo biomodulation, which is based on metabolic activation through through stimulation of the cellular respiratory chain in mitochondria that in turn increases vascularization and enhances the supply of oxygen in hypoxic cells.
