This document discusses lasers used in periodontics. It provides an overview of laser physics, types of lasers including diode, CO2, Nd:YAG and erbium lasers, and their applications in soft tissue procedures and osseous surgery. The benefits of lasers include less pain, better hemostasis and wound healing compared to conventional methods. Safety protocols must be followed when using lasers to prevent eye and tissue damage. Lasers are becoming more widely used in dentistry due to their advantages over traditional techniques.

1. • INTRODUCTION
• HISTORY
• CLASSIFICATION
• LASER PHYSICS
• LASER EFFECTS ON TISSUE
• LASER TYPES
• LASER SAFETY
• APPLICATIONS IN DENTISTRY
• LASER APPLICATION IN PERIODONTICS
• BENEFITS & DRAWBACKS OF DENTAL LASERS
• DENTAL LASERS IN THE FUTURE
• CONCLUSION
LASERS IN PERIODONTICS

2. INTRODUCTION
• The word LASER is an acronym for “light amplification by
stimulated emission of radiation.
• It refers to a device that emits light that is spatially coherent
and collimated.
• A laser beam can remain narrow over a long distance and it can
be tightly focused.

3. HISTORY
Einstein 1960 brought forth the concept of simulated emission of light.
This ultimately introduced the concept of Lasers.
Charles Hard Townes, 1951 an American physicist invented the MASER
(Microwave Amplification by Stimulated Emission of Radiation)
Maiman 1960 introduced the first Laser using synthetic ruby rod (RUBY
LASER)
Goldman 1965 established the first laser medical laboratory using ruby laser.
CO2 laser was 1st invented by Kumar Patel in 1964 and it was 1st applied to
periodontal surgery by Pick in 1985.

4. CLASSIFICATION
1.According to ANSI & OHSA standards lasers are classified as
Class I : Low powered lasers that are safe to use.
Class IIa : Low powered visible lasers that are hazardous only
when viewed directly for longer than 1000 seconds.
Class IIb : Low powered visible lasers that are hazardous when
viewed for more than 0.25 seconds.

5. Class IIIa : Medium powered lasers & hazardous if viewed for less
than 0.25 seconds without magnifying optics.
Class IIIb : Medium powered lasers, hazardous when viewed
directly.
Class IV : High powered lasers, that produce ocular skin and fire
hazards.

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

7. 5.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).

8. LASER PHYSICS

9. PROPERTIES OF LASERS

10. LASER EFFECTS ON TISSUES
• Reflection
• Transmission
• Scattering
• Absorption

11. LASER TYPES

13. LASER DELIVERY SYSTEMS

14. LASER OPERATION PARAMETERS
FOCUSED DE-FOCUSED
• Laser beam hits tissue at
its focal point- narrowest
diameter
• Beam moved away from
its focal point

15. 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

16. THEORETICAL ZONES OF TISSUE CHANGE ASSOCIATED
WITH SOFT TISSUE EXPOSURE TO LASER LIGHT

17. BENEFITS OF LASER – TISSUE INTERACTION
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

18. THEORETICAL ZONE OF TISSUE CHANGE ASSOCIATED WITH HARD DENTAL
TISSUE EXPOSURE TO LASER LIGHT
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

19. • Photothermal
• Photochemical
• Photoacoustic
• Biostimulation
• Photodynamic
• Photovaporolysis
• Photoplasmolysis
LASER EFFECTS ARE DUE TO:

20. PHOTOTHERMAL
1. Transformed into heat
2. Primary photothermal laser – tissue reactions are
Incision/Excision
Ablation/Vaporization
Hemostasis/Coagulation
3. All these interactions are based upon the Spot Size

22. • The photoacoustic effect is a conversion between light and
acoustic waves due to absorption and localized thermal excitation.
• When rapid pulses of light are incident on a sample of matter, they
can be absorbed and the resulting energy will then be radiated as
heat.
• This heat causes detectable sound waves due to pressure variation in
the surrounding medium.
PHOTOACOUSTIC

23. PHOTOVAPOROLYSIS
• Ascendent heat levels-phase transfer from liquid to vapor
PHOTOPLASMOLYSIS
• Tissue removed by formation of electrically charged ions and
particles in a semi-gaseous high energy state.

24. PHOTOCHEMICAL
• Absorption by chromophores
• Tissue response in terms of change of covalent
structure
BIOSTIMULATION
• Believed to work towards healing by stimulation of
factors and processes
• Below surgical threshold
• Useful for pain relief, increased collagen growth and anti-
inflammatory activity

25. WHAT DOES THE OPERATOR CONTROL?

26. 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

27. 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

28. • The chief advantage of the diode lasers is one of a smaller
size, portable instrument.
• Hot tip effect heat accumulation at tip thick
coagulating layer
• DIODENT - visible red diode 655 nm
• Less tissue penetration, deeper coagulation

29. ND:YAG LASER
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

30. CO2 LASER
LASER CHARACTERISTICS
WAVELENGTH 9300, 9600, 10600 nm
ACTIVE MEDIUM Carbon dioxide gas
DELIVERY SYSTEM Articulated arm
FIBER DIAMETER Periotip aperture- 0.5mm
MODE OF OPERATION Continuous wave, gated pulsed mode.
Used in focused and de-focused modes

31. • Use limited to soft tissue procedures as it
produces severe thermal damage, like
cracking, melting and carbonization of the
adjacent root cementum and dentin. Spencer
(1996), Israel et al(1997), Barone et al
(2002)
• Highly absorbed by main mineral component
of hard tissue, especially phosphate ions
leading to Carbonization of organic
components and melting of inorganic ones
CARBONIZATION

32. Er YAG- 2940 nm: Zharikov et al 1975.
Er Cr YSGG- 2780 nm: Zharikov et al 1984 and Moulton et al 1988.
1988: Phagdiwala: Er YAG laser: ability to ablate the dentinal hard tissue.
1989: Pulsed Erbium laser: Keller and Hibst - enamel , dentin and bone.
1995: Commercially available.
1997: Introduced for use in dentistry.
ERBIUM FAMILY OF LASERS

33. APPLICATIONS IN DENTISTRY
• Treatment of aphthous ulcer(photo dynamic therapy)
• Dentin desensitization
• Soft tissue biopsy
• Vestibuloplasty
• Modification of root canal walls
• Sterilization of root canals
• Apicoectomy
• Bleaching
• Tooth preparation
• Cavity preparation
• removal of impacted tooth

34. LASER APPLICATION IN
PERIODONTICS
• Frenectomy
• Frenotomy
• Gingivectomy
• Gingivoplasty
• Exposing implants in second stage surgery
• Depigmentation of gingiva
• Crown lengthening
• Gingival curettage
• Peri-implantitis
• Osseous surgery

35. C. In addition, the bacteriocidal effects of FR pulsed Nd YAG laser plus intraoperative use of topical antibiotics
are designed for the reduction of microbiotic pathogens (antisepsis)within the periodontal sulcus and
surrounding tissues. A second pass with the 635µ/ sec “long pulse” laser finishes debriding the pocket
D. Gingival tissue is compressed against the root surface to close the pocket and aid with formation and
stabilization of a fibrin clot
E. The wound is stabilised, the teeth are splinted and occlusal trauma is minimized to promote healing
F. Oral hygiene is stressed and continued periodontal maintenance is scheduled. No probing is performed for at
least 6 months
APPLICATIONS OF LASER (LANAP)
A. The primary endpoint of LANAP is debridement of inflamed
and infected connective tissue within the periodontal sulcus
B. B. Removal of calcified plaque and calculus adherent to the
root surface

36. Conventional method- tactile feel.
Latest: Er YAG laser with fluorescent feedback system for calculus
detection.
Rationale:
Difference in the fluorescence emission properties of calculus and
dental hard tissue when subjected to irradiation with 655 nm diode
laser.
Commercially available as Key Laser III, Ka Vo, Germany
SUBGINGIVAL CALCULUS DETECTION- UNIQUE
APPLICATION FOR LASER

37. SUB- GINGIVAL CALCULUS REMOVAL
AUTHOR AND
YEAR
LASER STUDY DESIGN OBSERVATION
PERIOD
FINDINGS
Cobb et al 1992 Nd YAG EXP (Laser, laser +RP,
RP +LASER)
Control
Immediately after
treatment
Low effectiveness of
calculus removal
Decrease in no. of bacteria
Scharwz F et al
2003
Diode Exp (laser)
Control(SRP)
Immediately after
treatment
Not effective for calculus
removal.
Thermal damage to root

38. ROOT SURFACE ALTERATIONS
DIODE LASER Nd YAG LASER
• Dry or saline moistened root
surface – no detectable alterations
• Morlock BJ et al 1992 : surface
pitting, craters, melting,
carbonization of root surface

39. ROOT SURFACE ALTERATIONS
CO2 LASER ERBIUM LASER
• Spencer P, Cobb CM et al 1996
• Carbonised layer on root surface
• Cyanamide, cyanate ions- detected
on carbonised layer – FTIS method
• Aoki et al 2000: Er YAG with
coolant:
• Micro irregular surface
• No thermal effects as cracking,
fissuring

40. PHOTODYNAMIC THERAPY

42. • Helium – neon laser
• Gallium – aluminum – arsenide diode laser
• Gallium – arsenide diode laser
• Argon ion laser
• Defocused Co2 laser
• Defocused Nd:YAG laser
Biostimulation effects of low level laser
LOW LEVEL LASER THERAPY

43. • Reduction of discomfort / pain (Kreisler MB et al 2004).
• Promotion of wound healing (Qadri t et al 2005).
• Bone regeneration (Merli LA et al 2005).
• Suppression of inflammatory process. (Qadri T et al 2005).
• Activation of gingival and periodontal ligament fibroblast
(Kreisler M et al 2003), growth factor release (Saygun I et al 2007).
• Alteration of gene expression of inflammatory cytokines
(Safavi SM et al 2007).
• Photo biostimulation (Garcia et al 2012)
BIOSTIMULATION OF LOW LEVEL LASERS

44. LASERS USED: CO2 AND ERBIUM FAMILY
Involves use of lasers for
calculus removal,
osseous surgery,
de-toxification of the root surface and bone,
granulation tissue removal
Advantage of Laser:
Better access in furcation areas, hemostasis, less postoperative
discomfort, faster healing.
SURGICAL POCKET THERAPY - LASERS

45. MANAGEMENT OPTIONS-
Conventional- plastic curettes and antibiotics.
New option- Laser
Rationale:
Disinfection and de-contamination of implant surface.
Granulation tissue removal.
LASERS USED: DIODE, CO2, ERBIUM FAMILY.
LASERS CONTRA-INDICATED: ND:YAG (IMPLANT
DAMAGE).
IMPLANT THERAPY- MANAGEMENT OF
PERIIMPLANTITIS

46. • Reports - laser created wounds heal more quickly and produce
less scar tissue than conventional scalpel surgery.
• Contrary evidence from studies in pigs, rats and dogs indicate
that the healing of laser wounds is delayed, that more initial
tissue damage may result, and that wounds have less tensile
strength during the early phase of healing. (Pick et al 1990)
HEALING AFTER LASER THERAPY

47. • Abergel et al (1984) experiment with cultured human skin
fibroblasts showed that collagen production and DNA
synthesis were delayed when the fibroblasts were exposed
to Nd: YAG laser radiation.
• Iliria et al (2003) analyzed the biocompatibility of root
surfaces treated by Er: YAG laser and concluded that laser
irradiation promoted faster fibroblast adhesion and growth
than surfaces treated with root planing.
• Garcia et al (2012) LLLT enhanced healing
biostimulation

48. ADVANTAGES OF LASER IN SURGICAL PERIODONTICS
• Minimum collateral effects result in decreased tissue damage and thus
enhance healing
• Patient comfort can be enhanced
• Hemostasis and coagulation are possible, making the laser essential
for medically compromised patients
• Some procedures can be performed with topical anesthesia only
• The concept of minimally invasive dentistry (MID) can be achieved
• Lasers are safe if the user adheres to protocols

49. Diode and Nd YAG
 Effective for cutting and
reshaping of soft tissue
 Good hemostasis
 Greater thermal effects
 Thicker coagulated layer
CO2 laser
 Rapid ablation of soft tissue
 Good hemostasis
 Effective even for thick tissue
 Risk of charring- thermal damage
GINGIVAL SOFT TISSUE PROCEDURES

50. Er YAG
 Fine cutting can be done
 Less hemostasis as compared to other lasers
 Very less thermal damage: use with irrigation
 Width of thermally affected layer: 5-20 microns (Aoki et al 2005)
 Safer even in thin tissues
 Useful to remove melanin and metal tattoos

51. LASER SAFETY
• Protective eye wear must be worn by the patient and the operator.
• Surgical environment must have a warning sign posted with limited access to
the treatment room.
• High volume suction must be used to evacuate the laser plume formed by
tissue ablation.
• Normal infection control must be followed.
• The laser itself must be in good order.
• Mask must be of appropriate filtering capacity (0.1micron filtration mask) to
prevent inhalation of laser plume which may be infectious or carcinogenic.

52. EYE DAMAGE
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

53. LASER BENEFITS
• Less pain,
• Less need for anesthetics,
• No risk of bacteremia,
• Excellent wound healing with no scar tissue formation,
• Hemostasis,
• Usually no need for sutures,
• Ability to remove both hard and soft tissue,
• Laser can be used in combination with scalpels.

54. LASER DRAWBACKS
• Relatively high cost of the device
• A need for additional education( especially basic
physics)
• Every wavelength has different properties and should
be used based on that knowledge
• The need for implementation of safety measures.

55. LASER IN THE FUTURE
• Optical coherence tomography using laser to create a
3 dimensional image will be tremendous advance for
dental diagnosis.
• Laser doppler instruments will be able to measure
blood flow rates to assess inflammation.
• Selective ablation of calculus and bacteria and
enamel hardening for caries resistance are some new
procedures which are under development.

56. CONCLUSION
• Lasers are becoming more commonplace and even
routine, either as an adjunctive treatment
methodology or as stand-lone additions to the dental
armamentarium.
• Researchers continue to investigate new laser
wavelength and clinical applications as they apply to
dentistry.
• The growing number of dental practitioners, will
continue to advance the application of Einstein’s
“splendid light” in their operatories, to the benefit of
patients.

57. REFERENCES
• Cobb et al : Lasers and the treatment of periodontitis: the essence and the
noise. Periodontology 2000, Vol. 75, 2017, 205–295
• Journal of Indian Society of Periodontology;vol:19;(July-August 2015)
• Robert A. Convissar: Principles and Practice of LASER DENTISTRY
• Carranza: Clinical Periodontology; 10th edition.
• Dental clinics of North America “ Lasers in Clinical dentistry”. Oct
2004. Vol 48. Issue 4