13. Components
of laser
• The inner part of laser, or the
components of laser, are as follows:
• A)Optical cavity
• B) Two mirrors- one at each end of
optical cavity
• (C) Excitation sources
• (D) Cooling system
• (E) Focusing lenses
• (F) Other controls
20. Two mirrors-
• Mirrors are parallel to each other
• Partially- reflective mirror with 5-10% transmission
21. • Principle of interference-
Constructive interference – when the waves are in phase
Destructive interference – when waves not in phase
22. • Dielectric mirrors: A dielectric mirror, also known as a Bragg mirror, is a type
of mirror composed of multiple thin layers of dielectricmaterial, typically
deposited on a substrate of glass or some other optical material.
23. • Alternating pattern of high and low RI materials
• Depending on the number of layers in the mirror – 20 or more layers – the
reflectance is 100% for atleast one particular wave length
24. EXCITATION SOURCES
This applies to the energy or excitation level of a laser medium.
The energy possessed α external or internal energy from a source.
E.g.
Electrical discharge – CO2 laser, He:Ne, Krypton
Chemical reaction
External high powered radiant source as xenon or krypton flash lamp – Nd:YAG, Ruby
laser.
Alternating magnetic fields – X-ray lasers
Excitation sources
25. This causes a
process called
OPTICAL PUMPING,
in which energy is
driven into the
resonant chamber.
This energy is used
to change the
energy level or
quantum state.
27. Thermal effect of LASER radiation
Temperature
37 0C
45 0C
50 0C
60 0C
80 0C
100 0C
150 0C
300 0C
Effect
Normal
Hyperthermia
Reduction in enzyme activity, cell immobility
Denaturation of proteins and collagen, coagulation
Permeabilization of membranes
Vaporization, thermal decomposition
Carbonization
Melting
28. Potential advantages of
LASER
• No-touch techniques
• Reduced blood loss.
• Limited fibrosis.
• Fiber optic delivery.
• Reduction in spread of
metastasis.
29. • Fewer instruments in the field.
• Reduce post-operative pain.
• Sterilization of the impact site.
• Dry surgical field.
• Reduced edema.
Potential advantages of LASER
30. • Corneal or retinal burns (or both). Chronic exposure to excessive
levels may cause corneal or retinal injury
• Severe burns & scarring.
• Electrical hazard
• Fire
Potential hazards of LASER
31. 1. Fiber optic delivery system
2. Hollow Fiber: Er: YAG and CO 2 lasers
TYPES OF LASER LIGHT DELIVERY
32. 3. Articulated arm delivery system
4. Handpieces-close contact and non-contact handpiece
TYPES OF LASER LIGHT DELIVERY
36. Effect of distance of laser beam on the spot-size at
target tissue surface Effect of focused and defocused laser beam on
target tissue
Focused beam results in well-defined incision whereas a defocused beam
causes ablation.
37. • The exposure time is the amount of time the operator keeps the laser
light directed at the tissue.
38. Tissue is vaporised with each pulse and no significant and no thermal damage
occurs beyond the site of laser impact.
Selective Photothermolysis
This was first theorised by Anderson and Parrisch in 1983.
39. Lasers used in dental practice can be classified into several
categories according to:
(1)the range of wavelength,
(2) the lasing medium, such as gas laser and solid laser
(3) tissue penetration - soft tissue and hard tissue lasers
(4) The risk related to laser application, and
(5) potential hazards.
CLASSIFICATION OF LASERS
47. CARBON DIOXIDE LASERS
• Developed by Patel in 1964
• Emits light in the invisible mid infrared portion of the spectrum at a
wavelength of 10600 nm.
• Uses a mixture of carbon dioxide, nitrogen,
and helium as its medium.
• Excited by a high-voltage electrical current.
48. CARBON DIOXIDE LASERS
• 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.
49.
50. Advantages
of CO2 Laser
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
via microscopes
8. Reduced pain – neuron sealing, decreased
pain mediator release.
9. Minimized tumor cell dispersion by
lymphatic sealing.
55. 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
56. 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.
57. 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
The difference between CO2 and Er:YAG laser lies in their differing absorption coefficients:
Er:YAG lasers are much more strongly absorbed in the water. On the other hand, CO2 lasers
show very high absorption on the tissue surface.
58.
59.
60. ARGON LASERS
• 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.
• It is fibre optically delivered with fibre diameter 300μm
in continuous wave and gated pulsed modes.
• 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.
61. Argon LASER
These lasers are useful in the treatment of-
• pigmented lesions,
• vascular anomalies and
• soft tissue incisions and ablations.
62.
63. ND: YAG LASERS
• Geusic and coworkers in 1964, with
wavelength of 1064 nm
• A flashlamp used as energy source
• Nd: YAG penetrates water upto 6mm depth
before attenuated to 10% of its original
strength.
• Energy. scattered rather than absorbed.
• Uses
64. Excellent for the treatment of-
• vascular lesions
• intraoral and extraoral pigmented lesions
• achieving hemostasis.
• open TMJ arthroplasty,
• malignant lesion excision,
• black and blue tattoo pigment removal,
With ND: YAG laser procedures anesthesia is required in less than 50% of
cases.
65. KTP LASER
• This laser is a modified version of the
Nd: YAG laser.
• With the addition of a frequency-
doubling crystal, this laser emits
laser light at the 532-nm wavelength
• Uses
66.
67. DIODE LASER
• Wavelength - 800nm to 980nm, 1-10W power
• Light energy
• Employs a flexible optic fibre
• They run in either CW or pulsed mode.
• Diode laser is one of the most versatile possible treatments options.
68. In oral surgery, these machines can be used in numerous clinical procedures,
• soft tissue surgery,
• second stage implant recovery, in peri-implantitis,
• sub-gingival curettage etc.
ADVANTAGES-
• Disinfects the treated area.
• Ease of operation, due to the sub-millimetre dimension and their extreme
compactness.
69.
70. 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.
71. Q-SWITCHED
RUBY LASER
• To treat some pigmented lesions
and tattoos effectively.
• The slightly longer wavelength
allows for greater depth of
penetration and is more effective in
the removal of deeper lesions
72. FLASHLAMP-PUMPED
PULSED DYE (FLPPD) LASER
• pigmented and hemopigmented
lesions, tattoo removal.
• scar revision,
• achieving hemostasis,
• photodynamic cancer therapy,
• ablation of salivary gland and kidney
stones,
73. COPPER VAPOR
LASER
• At wavelengths of 511 and 578
nm,
• used to ablate some pigmented
lesions such as lentigines,
ephelides, lentiginous nevi, and
tattoos
74.
75. • These lasers emit ultraviolet light at 193 to 351 nm,
• Active medium- Halide gas
• It is currently used for keratotomy to reshape corneal tissues and to
correct poor vision.
EXCIMER LASER
76. LASER SAFETY IN SURGERY AND ANESTHESIA
Personnel
safety
Drapes: Not
recomm
ended
Paper Plastic Recommend
ed
Cloth
saturate
d with
water
around
the field
Laser
resistant
drapes for
personnel,
anesthetic
circuit.
77.
78. • Class 1 : 1M
• Class 2: 2M
• Class 3R
• Class 3B
• Class 4
There is no such thing as an “eyesafe” Class 3b
or Class 4 laser!!!
79. • Class 1 : 1M
• Class 2: 2M
• Class 3R
• Class 3B
• Class 4
There is no such thing as an “eyesafe” Class 3b
or Class 4 laser!!!
80. • Field preparation
Alcohol as a part field is to be avoided
If not the alcohol should vaporize completely before draping.
Protection of patient’s throat and delicate oral tissues from accidental beam impact
Use of wet gauze packs or towels to avoid reflection from shiny metal surfaces
Adequate high speed evacuation should be used to capture laser plume, which is biohazard
• Specular reflection
The surgical beam should be tested for alignment prior to each use of the machine.
No instruments are passed across the intended path of laser.
LASER SAFETY IN SURGERY AND ANESTHESIA
81. Anesthetic agents
• Inflammable agents like ether and cyclopropane is absolutely
contraindicated in laser surgeries.
• Instead halothane, enflurane, isoflurane and sevoflurane
• If surgery along the airway – helium and oxygen can be used
83. Eye
• Retinal damage
• Even if eyes closed it can penetrate the eye lids
• Only normal saline is used to lubricate the eye,
petroleum based is avoided.
84. Skin
• Avoid alcohol preparation
• Hairs near the field can ignite. It can be kept
moist.
Teeth
• Etching and disfigurement of enamel
• Dental splints fabricated from laser resistant
material.
85. • Endotracheal tubes
Nonmetallic
• Red rubber, PVC, silicon – red rubber is overall better.
• Tubes wrapped with metallic foil – mucosal injury
• Wrapped with metallic tape of copper or silver.
• Silver anode sheet that has spongy water-absorbant material outside and adhesive inside
• Ceramic coated endotracheal tube by Xomed (Florida)
Metallic
• Norton and Devos endotracheal tubes , Porch tube are used through oropharynx or trachea.
• Cuffed metallic tubes are available.
• Water is injected in to the cuff to inflate
86. 1. Post signs that lasers are being used at all possible entry points
2. Eye shields must be worn by all personnel at all times
3. Safety shields must be used
4. A bucket of sterile water should be immediately available in the
operating room
5. Credentialing of surgeons for the use of each type of laser and
laser apparatus is needed.
6. Short bursts, intermittent lasing, and changing from area of the
lesion to other sequentially
7. Cooled irrigation to keep the tissues from heating
97. Applications in OMFS
• Gingivectomy.
• Frenectomy.
• Removal of granulation tissue.
• Removal of melanin pigmentation and metal tattoos.
• Subgingival debridement and curettage.
• Osseous recontouring as well as in implant surgery. Maintenance
of implants.
• Low Level Laser Therapy.
98. Soft Tissue Clinical Applications-
The most popular and effective lasers nowadays for soft tissue procedures are CO2, Nd:YAG
and Diode lasers.
There are many categories of soft tissue procedures that can be treated by lasers, such as
• de-epithelialization of reflected flaps,
• depigmentation,
• second stage exposure of dental implants,
• sub-gingival debridement curettage,
• incisional and excisional biopsies of both benign and malignant lesions,
• removal of granulation tissue,
• coagulation of free gingival graft donor site,
• irradiation of apthous ulcers,
• removal of diseased tissue around the implants etc.
99.
100. FACIAL SKIN RESURFACING
Indications:
1. Photo damage: Dyschromias & Rhytides
2. Atrophic (depressed) scars : Post acne
Chromophore: water
Mechanism: Thermal ablation of Epidermis
& papillary dermis
Lasers
a) Single pass CO2
b) Modulated Er : YAG
101.
102. VASCULAR LESIONS
Chromophore– Oxyhaemoglobin
Absorption wavelengths – 418, 542, 577 nm
Laser of Choice: FPPDL – wavelength – 585, 590, 595, 680 nm
Fluence –5-14 J/cm2
Spot Size – 2-10 mm
Density – Less than 10%
Pulse Duration: 1.5-40 milliseconds
Delay between pulses – 10-500 milliseconds
103.
104. • Commonly used is pulsed dye laser at 580 nm &short
pulses 450 microseconds
• Haemangiomas
• Venous malformations
Vascular lesions
116. Peripheral Ossifying Fibromas
These occurs solely on the soft tissue overlying the alveolar
process. It is a
common gingival growth that usually arises from the interdental
papilla.
These lesions can be effectively treated with Er,Cr:YSGG.
Iyer VH et al. reported that the outcome was painless experience to
the patient, minimal intraoperative bleeding in the surgical field
and excellent healing of the operated area in 1 week period.
Iyer VH, Sarkar S & Kailasam S (2012) Use of the Er,Cr:YSGG Laser in the Treatment of Peripheral
Ossifying Fibroma. International Jour-nal of Laser Dentistry 2, 51-55.
117. Denture-induced fibrous hyperplasia
This is a response of tissues to a chronically ill fitting denture and present as
a benign condition which frequently coexists with denture stomatitis.
Kumar NJ et al. successfully treated the case of denture induced fibrous
hyperplasia with the help of carbon dioxide laser and concluded that CO2
lasers could be an excellent alternative to conventional modalities.
Kumar NJ & Bhaskaran M (2007) Denture-induced fibrous hyperplas-ia:treatment with carbon
dioxide laser and a two year follow-up. I Journal of Dental Research 18, 135-7e.
118. Mucoceles
These are benign lesions of the oral cavity that develop due to extravasation or
retention of mucous from salivary glands in the subepithelial tissue generally in
response to trauma.
Pedron IJ et al. on the basis of findings of their study concluded that laser
treatment provides satisfactory results and allowed for a satisfactory
histopathological examination of the excised tissue in case of mucocele.
Pedron IG, Galletta VC, (2010) Treatment of mucocele of the lower lip with diode laser in pediatric
patients: presentation of 2 clinical cases. Pediatric Dentistry 32, 539-41.
119. Hemangiomas
These are benign vascular proliferations consisting of numerous capillary
structures usually present on the tongue, lips, mucous membrane and
gingiva.
Genovese WJ et al concluded that application of gallium arsenide (GaAs) have
high potency diode laser in the treatment of hemangionma reduced bleeding
during excisional surgery, with a consequent reduction in operating time and
promoted rapid postoperative hemostasis.
Apfelberg DB et al recommended the laser treatment for excisional surgery of
hemangioma.
Genovese WJ, dos Santos MT,Faloppa F & de Souza Merli LA (2010) the use of surgical diode laser in
oral hemangioma: a case re-port. Photomedicine and Laser Surgery 28,147-51.
Apfelberg DB, Maser MR, Lash H & White DN (1985) Benefits of the CO2 laser in oral hemangioma
excision. Plastic and Reconstruc-tive Surgery 75, 46-50.
120. Lymphangioma
It is often asymptomatic and a slow growing
painless cystic mass covered by healthy mucosa.
Despite being a congenital benign lesion,
lymphangioma may cause severe esthetic
deformities, and surgical excision is the main
treatment.
Dos Santos et al reported that the use of CO2 laser
was practical, easy to carry out and effective on
the treatment of oral lymphangiomas, with no
lesion recurrence.
dos Santos Aciole GT, Santos NRS, (2010) Surgical Treatment of Oral Lymphangiomas with CO2 Laser:
Report of Two Uncommon Cases. Brazilian Dental Journal 21,365-9.
121. Premalignant and malignant lesions
Laser resection/ablation is recommended for oral dysplasia to prevent not only
recurrence and malignant transformation but also postoperative oral
encountered by other conventional modalities.
Van der Hem PS et al concluded that leukoplakia or hyperkeratotic lesions
cryotherapy ablation and CO2 laser is used and the operated area heals
This is an effective, non- morbid, inexpensive, quick, and relatively painless
method of managing such condition.
Kok & Ong concluded that the use of CO2 laser in the treatment of oral lichen
planus and lichenoid reaction shows positive results in relieving symptoms.
Van der Hem PS, Nauta JM, van der Wal JE & Roodenburg JL (2005) the results of CO2 laser surgery in
patients with oral leukoplakia: a 25 year follow up. Oral Oncology 41, 31-7.
Kok TC & Ong ST (2001) the effects of CO2 lasers on oral lichen planus and lichenoid reactions. Annals
of Dentistry University of Maaya 8, 35-42.
126. Infectious lesions
Erbium laser may be used for ablation or decontamination of infective lesions.
Lasers are used in treatment of herpetic, candidiasis, and papilloma virus
lesions.
Gaeta GM (2013) laser treatment in medicine and oral pathology.
Http://www.Giovannimariagaeta.It/laser %20book%202010.Pdf
127. Dentigerous cysts
These are benign odontogenic cysts associated with the crown of
an unerupted tooth. They can expand the cortical bone and cause
displacement of teeth and root resorption in the adjacent teeth.
Boj JR treated a case of dentigerous cyst by preparation of mucous
fenestration using an erbium laser followed by drainage of the fluid
content and curettage and the injury was success-fully resolved.
Boj JR, Poirier C (2007) Laser-assisted treatment of a dentigerous cyst: case report. Ped dent 29, 521-4.
128. Cancer
The CO2 laser currently has the greatest significance in otorhinolaryngology,
predominantly in the treatment of carcinomas of the upper aerodigestive tract.
The neoplastic cells can be removed by hyperthermic (cells are destroyed by
laser heat or photodynamic combination of special photosensitive drug with
specific type of laser) methods.
López-Álvarez F,Rodrigo JP,(2011) Transoral laser microsurgery in advanced carcinomas of larynx
and pharynx. Acta Otorrinolaringológica Española 62, 95-102.
133. Hard Tissue Clinical Applications
• removal of impacted teeth under bone,
• apicoectomies,
• osseous re-contouring,
• implant and bone osteotomies,
• bone grafting,
• jaw continuity defects,
• removal of inflammatory tissues around implants,
• crown lengthening,
• uncovering of permanent teeth for orthodontic purposes etc.
Erbium (Er) family of lasers can be the lasers of choice.
Er lasers use extremely short pulse durations and can easily ablate layers
of calcified tissue with minimal thermal effects.
134. Hard Tissue Clinical Applications
Prevention of caries
Detection of incipient caries
Cavity preparation
Enamel etching
Desensitization
135. Hard Tissue Clinical Applications
Bleaching/ fluorosis
t/t of fractured tooth
Pulpotomy
Removal of old restoration-gold, ceramic
Root canal therapy
Temporomandibular Joint Treatment: reduce pain and
141. • Photodynamic therapy (PTD) is
currently being evaluated for the
treatment of head and neck, skin, intra-
abdominal, and other types of cancers.
• carbon dioxide laser and other lasers
have also been used in the micro
anastomosis of nerve and vascular tissue
with some success.
142.
143.
144.
145.
146. CONCLUSION
Lasers - alternative to conventional surgical systems
Lasers are a “new and different scalpel” (optical knife, light
scalpel)
The application of lasers has been recognized as an adjunctive or
alternative approach in soft tissue surgeries. Laser treatments
have been shown to be superior to conventional mechanical
approaches with regard to easy ablation, decontamination and
hemostasis, as well as less surgical and postoperative pain in soft
tissue management.
147. REFERENCES
1. Fonseca, oral and maxillofacial surgery, vol. 1
2. Clinics of North America, LASERS in OMFS, vol.16, May2004
3. Fundamentals of LASER dentistry, Kripa Johar
4. Theodoros Tachmatzidis, Nikolaos Dabarakis ,Technology of Lasers and
Their Applications in Oral Surgery: Literature Review, BALKAN
JOURNAL OF DENTAL MEDICINE ISSN 2335-0245
5. Dragana Gabrić, Advanced Applications of the Er:YAG Laser in Oral and
Maxillofacial Surgery, A Textbook of Advanced Oral and Maxillofacial
Surgery Volume 2, chapter 34
