Laser science is principally concerned with quantum electronics, laser construction, optical cavity design, the physics of producing a population inversion in laser media, and the temporal evolution of the light field in the laser. It is also concerned with the physics of laser beam propagation, particularly the physics of Gaussian beams, with laser applications, and with associated fields such as non-linear optics and quantum optics.

1. LASER
LASERS AND IT’Z APPLICATIONS IN DENTISTRY
By: Lokender Yadav
1

2. • Introduction
• History
• Fundamentals Of Laser Operation
• Classification Of Lasers
• Current Uses
• Technique For Use Of Laser In OMFS
• Laser Safety
• Conclusion
2

3. 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

4. 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. 5

6. 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

7. Absorption
E1
E2
7

8. Spontaneous Emission 8

9. Stimulated Emission 9

10. 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

11. Fundamentals Of Laser Operation
 Components -
 Active medium [ Lasing Medium ]
 Pumping mechanism
 Optical Resonators
 Laser Delivery System
 Cooling system
 Control Panel
11

12. 12

13. E1
E2
h
(a)Absorption
h
(b) Spontaneousemission
h
(c)Stimulated emission
In
h
Out
h
E2
E2
E1 E1
Absorption,spontaneous(randomphoton) emission and stimulated
emission.
© 1999 S.O. Kasap, Optoelectronics (Prentice Hall)
13

14. Stimulated Emission 14

15. Properties Of LASER
Monochromaticity
Directionality
Coherence
Brightness
15

16. 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

17.  Photo thermal interactions-
Photo ablation – removal of tissue by vaporization and
super 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 wave
generation.
17

18.  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

19. LASER INTERACTION WITH
ORAL BIOLOGIC TISSUE
19

20.  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.
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21. 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

22. 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

23. Medical
Classification Of
Lasers
High Power Lasers-
Used for surgical
purpose
Low power Lasers-
Used to promote
tissue regeneration
23

24. 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
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25. Photodynamic Therapy 25

26. 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

27. 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 for
tooth whitening , curing of composites , curettage etc
Color-Blue
27

28. 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

29. 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

30. 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
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31. 31

32. 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

33. Lesions treated
 Fibroma
 Mucocele
 Papilloma
 Gingival lesion
 Salivary stones
 Malignancy removal
 Vestibuloplasty
 Incisional and excisional biopsy
 Tongue lesion treatment
33

34. Technique for ablation and vaporization
 Laser vaporization is an effective , non-
morbid , inexpensive , quick , and relatively
painless method of managing pre malignant
lesions.
 A spot size of 1.5 to 3mm is typical for most
intra oral vaporization procedures. The beam
is transverse in vertical strokes.
 A constant speed must be maintained to
create a uniform depth. Increasing depth can
be accomplished by increasing power.
 Allows for removal of a surface lesion in
layers.
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35. Uses Of Laser Ablation
 Solar chelitis
 Leukoplakia
 Dysplasia
 Lichen Planus
 Oral melanosis
 Nicotine stomatitis
 Tissue hyperplasia
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36.  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

37. 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

38.  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

39. 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

40. 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

41. 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

42. 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. 43

44. 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

45. Treatment Process 45

46. 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.
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