Post on 19-Aug-2015
LASERLASERS AND IT’Z APPLICATIONS IN DENTISTRY
By: Lokender Yadav
1
• Introduction
• History
• Fundamentals Of Laser Operation
• Classification Of Lasers
• Current Uses
• Technique For Use Of Laser In OMFS
• Laser Safety
• Conclusion
2
Introduction
Advances in technology are increasing and
changing the ways that patient experience dental
treatment. Technology helps to reduce treatment
time and treatment more comfortable.
One of the milestones in technological
advancements in dentistry is the use of LASERS.
The term Laser is the acronym for “Light
Amplification by Stimulated Emission of Radiation”.
They provide more efficient , more comfortable and
more predictable outcomes for the patient.
3
HISTORY
1917- Einsteen Theory of stimulated
emission
1958 – Townes & Schawlow Laser principle
1960 - Maiman Ruby laser
1961 - Johnson Neodymium ion doped
yttrium aluminium garnet rod
1964 - Patel CO2 Laser
1977 - Shafir First documented case in
OMFS using lasers
1989 – Terr Myers First Dental Laser – Nd:YAG
4
5
3 Mechanisms of Light
Emission
For atomic systems in thermal equilibrium with their
surrounding, the emission of light is the result of:
Absorption
And subsequently, spontaneous emission of energy
There is another process whereby the atom in an upper
energy level can be triggered or stimulated in phase with
the an incoming photon. This process is:
Stimulated emission
It is an important process for laser action
1. Absorption
2. Spontaneous Emission
3. Stimulated Emission
Therefore 3 process
of light emission:
6
Absorption
E1
E2
7
Spontaneous Emission 8
Stimulated Emission 9
Background Physics
In 1917 Einstein predicted that:
under certain circumstances a photon incident upon a
material can generate a second photon of
Exactly the same energy (frequency)
Phase
Polarisation
Direction of propagation
In other word, a coherent beam resulted.
10
Fundamentals Of Laser Operation
Components -
Active medium [ Lasing Medium ]
Pumping mechanism
Optical Resonators
Laser Delivery System
Cooling system
Control Panel
11
12
E1
E2
h
(a) Absorption
h
(b) Spontaneous emission
h
(c) Stimulated emission
Inh
Out
h
E2
E2
E1 E
1
Absorption, spontaneous (random photon) emission and stimulatedemission.
© 1999 S.O. Kasap, Optoelectronics (Prentice Hall)
13
Stimulated Emission 14
Properties Of LASER
Monochromaticity
Directionality
Coherence
Brightness
15
Photobiology Of Lasers
Photochemical
Biostimulation - Stimulatory effects of laser on biochemical and molecular processes that normally occur in tissues such as healing and
repair.
Photodynamic Therapy – induce reactions in
tissues for the treatment of pathologic condition.
Tissue fluorescence - used as a diagnostic
method to detect light reactive substance in
tissue.
16
Photo thermal interactions-
Photo ablation – removal of tissue by vaporization andsuper heating of tissue fluids , coagulation, and
hemostasis.
Photopyrolysis
Photomechanical
Photo disruption - breaking apart of structures by laser light.
Photoaccoustic interaction- involve removal of tissue with shock wavegeneration.
17
Photoelectrical Interaction- include photoplasmolysis
which describes how tissue is removed through the
formation of electrically charged ions and particles
that exist in a semi gaseous high energy state.
18
LASER INTERACTION WITH
ORAL BIOLOGIC TISSUE
19
Photocoagulation : Laser heats the tissues
to 60 deg C for a limited time
leading to coagulation of the
tissues with minimal alteration in the
appearance of tissue structure. As
a result of these proteins enzymes
cytokines and other bio active
molecules get denatured.
20
Classification Of Lasers
General Classification
Class 1 Non Hazardous Producing
Laser
Class 2 Hazard producing when
passed through magnifying
optics
Class 2 M Safe, if not viewed through
optical instruments
Class 3 R Safe with restricted beam
viewing
Class 3 B Direct viewing hazardous to
eye
Class 4 Serious injury potential to
eye and skin
21
Laser Classification as per medium
Used
Solid State Laser Eg-Neodymium-yttrium aluminium
garnet laser
Gas Laser Eg- Helium & Helium Neon
Excimer Laser Uses reactive gases like chlorine and
fluorine eg : argon laser
Dye Laser Complex dyes like Rhodamine 6G
22
Medical Classification Of
Lasers
High Power Lasers-Used for surgical
purpose
Low power Lasers-Used to promote
tissue regeneration
23
General Medical Uses Of Laser
Angioplasty
Cancer diagnosis
Cancer treatment
Laser hair removal , tattoo removal
Dermatology
Medical imaging
Microscopy
Ophthalmology
Optical coherence tomography
Prostatectomy
Surgery
Laser Dentistry
24
Photodynamic Therapy 25
Uses In Dentistry
Excimer Lasers
Hard tissue ablation/ Dental Caries removal.
Argon Fluoride / Xenon fluoride lasers are used.
They have a wave length from193nm to 308nm.
26
Gas Laser
Carbon dioxide lasers are used for intra oral and implant
soft tissue surgery , aphthous ulcer , melanin pigmentation.
Has a wavelength of 10600nm. Color- Infrared
Helium Neon Lasers has a wavelength of 637nm and is used
for dentin hypersensitivity , analgesia etc. Color-Red
Argon lasers having a wavelength of 488nm & are used fortooth whitening , curing of composites , curettage etc
Color-Blue
27
Diode Lasers
Indium Gallium Arsenide Phosphorous are used for
caries and calculus detection and has wavelength of
655nm. The color of the laser is Red.
Gallium Aluminum Laser – Intra oral Surgery , Implant
soft tissue surgery , sulcular debridement , Pulpotomy ,
root canal disinfection removal of enamel caries etc,
Wavelength- 840nm Color-Infrared
28
Solid state Laser
Neodymium:YAG Laser – Intra oral soft tissue surgery ,
sulcular debridement , analgesia , Pulpotomy , root
canal treatment, removal of gingival melanin
pigmentation . Has a wave length of 1064nm and is
infrared.
29
Erbium Group
Erbium:YAG is used for modification
of enamel and dentin surface ,
implant soft tissue surgery , sulcular
debridement , osseous surgery ,
treatment of dentin hypersensitivity
, apthous ulcer treatment etc
30
31
Techniques For Incisional Biopsy
Provide local or general anesthesia.
Outline the intended superficial incision
line without deep penetration.
Connect the outline marks.
Excise the specimen.
Obtain Homeostasis.
Consider the need for suturing.
Consider tagging the biopsy margins.
32
Lesions treated
Fibroma
Mucocele
Papilloma
Gingival lesion
Salivary stones
Malignancy removal
Vestibuloplasty
Incisional and excisional biopsy
Tongue lesion treatment
33
Technique for ablation and vaporization
Laser vaporization is an effective , non-morbid , inexpensive , quick , and relativelypainless method of managing pre malignantlesions.
A spot size of 1.5 to 3mm is typical for mostintra oral vaporization procedures. The beamis transverse in vertical strokes.
A constant speed must be maintained tocreate a uniform depth. Increasing depth canbe accomplished by increasing power.
Allows for removal of a surface lesion inlayers.
34
Uses Of Laser Ablation
Solar chelitis
Leukoplakia
Dysplasia
Lichen Planus
Oral melanosis
Nicotine stomatitis
Tissue hyperplasia
35
Lasers are also used in arthroscopic surgery of TMJ
Scar revision is also made possible these days with the help of pulsed dye
lasers[PDL]. PDL have hb as their chromophores and penetrate the epidermis
without de-epithelisation. They reduce scar tissue erythema and induce
collagen remodeling to flatten and soften scars. Indicated in cases with
erythematous and hypertrophic scars of maxillofacial region.
36
Low level Laser therapy
Also known as therapeutic laser
treatment.
Promotes tissue healing , reduces
edema , inflammation and pain.
Used in cases of – dermatological
conditions , neural ailments ,
mucoskeletal ailments etc
37
Easy and safe to handle
Improved surgical versality- ability to vaporize
coagulate and incise tissue.
Reduces / Eliminate bleeding.
Spot coagulation and vaporization gives
excellent hemostasis.
Reduces Operating Time.
Anesthesia free soft and hard tissue cutting
No need for suturing
Instant sterilization of surgical site
No sensory disturbances
No functional /mobility disorder
38
Demerits
Cannot be used in teeth with restoration and prosthesis.
Hazard to patient , operating and assisting team.
Maintenance requirements
Electrical hazards of laser equipments
Expense of laser equipments
Specialized arrangements
Fire hazards
39
Laser Hazards
Primary Hazards: Caused directly by laser beam.
Endangers mainly two organs-
Eyes and Skin
In case of eyes it damages retina , cornea , & the
lens and slight carelessness can destroy vision
permanently.
Secondary Hazards : Its related to operation of the
laser and are independent of radiation
characteristics.
40
Operating Room Safety
Use of non inflammable materials
Use of eye shields for the patient
Use of laser resistant shielding materials for surgical
field and for protecting anesthesia equipments
Certain anesthesia techniques may also decrease
potential hazard
Patient Safety
41
Personnel Safety
Post signs that lasers are being used
Eye shields to be worn by all personnel in operating room
Safety shields must be used
A laser safety officer should be stationed at the laser unit
Use only wet cloth in operative field
Use only non-combustible anesthetic agent
Avoid alcohol based topical anesthetic and gauze
Protect tissues adjacent to surgical site
42
43
Sterilization And Infection Control Of Laser Unit
Steam sterilization is the standard of care
Protective housing around the laser and
articulating arm should receive spray disinfectant
44
Treatment Process 45
Conclusion
The past decade has seen a variable explosion of research
into clinical application of lasers in dental practice. Laser
treatment not only is helpful in treating general problems of
the teeth but also helps to reduce the fear and anxiety of the
patient towards the treatment.
46
47