explained with Limited matter moreover I have included all the images. if you go through a standard textbook and referred to this PPT it will help you so much I hope It helps you

1. Nothing can dim the
light that shines
from within
GOOD MORNING

2. LASERS IN
OPERATIVE
DENTISTRY

3. CONTENTS
 Introduction
 Principle of laser
 Laser device
 Laser delivery system
 Laser emission modes
 Mechanism of action
 Laser tissue interaction
 Types of lasers
 Uses of lasers in conservative dentistry
 Laser hazards
 Laser safety
 Conclusion
 References

4. INTRODUCTION
• Widely used
• Effects on oral hard and soft tissues
• Approved by food and drug administration
• LASER - acronym

5. LASER

6. • First laser – Theodore Harold Maiman
• First laser marketed - co₂ laser

7. PRINCIPLE OF LASER

8. LASER DEVICE

9. LASER MEDIUM

10. OPTICAL CAVITY

11. POWER SOURCE

12. POPULATION INVERSION

13. LASER BEAM
Monochromatic, coherent and collimated

14. LASER DELIVERY SYSTEM
Articulated arm Flexible hollow wave guide Glass fiber optic cable

15. LASER EMISSION MODES
1. Constant on
2. Pushed on and off
3. Free running pulse mode

16. MECHANISM OF ACTION
• Photo thermal ablation – vaporize/coagulate
• Photomechanical ablation – disruption of
tissues
• Photochemical effects - cancer

17. LASER TISSUE INTERACTION
1. Photo biological
2. Photo chemical
3. Photo thermal
4. Photomechanical and
photo electrical

18. PHOTO BIOLOGICAL :

19. TYPES OF LASERS
SOFT LASER
HARD LASER

20. Soft laser
 Athermic
 Low energy
 Semi-conductor laser diodes
 Wave length – cellular activity
 Tissue regeneration and wound healing

21. SOFT LASER
He – Ne
Ga – Ar
Ga – Al – Ar

22. Hard laser
Thermic
High energy
Surgery- precise energy source
Cut, coagulate and vaporize

23. Hard laser
Argon laser
CO₂ laser
Nd – YAG laser

24. SOFT TISSUE LASERS
• Diode lasers
• Nd : YAG lasers
• Argon lasers
• Co₂ laser

25. ROUTINELY USED LASERS
CO₂ LASER
 Sealing of pit and fissure
 Welding of ceramic material to enamel
 Prevention of dental caries
Extremely high surface temperature
Inability to be transmitted via a fiber
optic cable

26. CO₂ LASER
 Principally absorbed by water molecule – cut many
hard and soft tissues
 10.6 µm
 Highest absorption in hydroxyapatite
 Adjacent structures
 Soft tissue surgeries

27. Nd : YAG LASER
• Usually large and bulky
• Pulsed energy at 1064nm
• Directed through 320µ silica fibre
• Cutting and coagulation of dental soft tissue
• Minimizes heat buildup

28. ARGON LASER
• Argon gas- active medium
• Energy

29. ARGON LASER
• Absorbed by……
• Haemoglobin
• Haemosiderin
• Melanin

30. ARGON LASER
• Not well Absorbed by……
• Enamel
• Dentin
• Non pigmented tissues

31. ARGON LASER
• Very useful for…..
• Cutting
• Vaporizing
• Coagulating
• Providing haemostasis

32. Er : YAG LASER
• Promising laser system
• Emission wavelength of 2.94µ
• Good absorption in all biological tissues
including enamel and dentin
• Zones of carbonization and necrosis

33. Er : YAG LASER
Radiant energy
Ablation
Alters morphological structure

34. Er : YAG LASER
Uses……..
Removal of healthy tooth
Carious decay
Composites and cements

35. Er : YAG LASER
Recommended for………
Osteotomy
Cyst removal
Apicoectomy

36. EXCIMER LASERS
• LIMITATION OF CO₂ AND Nd : YAG LASER
• Vaporization and carbonization
• Thermal side effects
• Structural changes
• Excimers: photo ablative decomposition

37. EXCIMER LASERS
• ArF – 193nm
• KrF – 248nm
• XeCl – 308nm
• XeF – 351 nm

38. EXCIMER LASERS
• ADVANTAGES:
• Minimal thermal effects
• No side effects
• Bacteriological effect on prepared surface
• Non carcinogenic
• Small zones of necrosis

39. EXCIMER LASERS
• DISADVANTAGE:
Very expensive

41. APPLICATION OF LASERS IN CONSERVATIVE
DENTISTRY
• Preventive effects
-CO₂, Nd:YAG, excimers
• Caries treatment
-CO₂, Nd:YAG, excimers, Er:YAG
• Composite resin light curing
-Argon, dye
• Tooth surface conditioning
-CO₂, Nd:YAG, excimers, Er:YAG

42. USES OF LASERS IN CONSERVATIVE
DENTISTRY
• Cavity preparation
• Caries detection
• Etching/ conditioning
• Curing of composites
• Dentin bonding
• Bleaching
• Dentin hypersensitivity

43. Cavity preparation
• Conventional methods
• Kinetic cavity preparation
• Preparation lasers

44. LASER SUPPORTED CAVITY
PREPARATION
• Er: YAG and Er, Cr: YSGG LASERS

45. LASER SUPPORTED CAVITY
PREPARATION

46. PRACTICAL PROCEDURES IN LASER-
ASSISTED CAVITY PREPARATION

47. CLASS I AND CLASS II PREPARATIONS

48. Curing of composites
ARGON with wavelength of 488nm
Advantages:
Shorter curing time
Better physical properties
Increased depth of cure
Better polymerization
Reduced polymerization shrinkage

49. Etching/ conditioning
Co₂ and Nd: YAG

50. FISSURE SEALING

51. Bleaching
KTP, Ar and Co₂ lasers
Rapidly decomposes H ₂O ₂

52. Dentin hypersensitivity

53. LASER HAZARDS
• Effects on eyes
• Skin
• Environmental hazards
• Electrical hazards

54. EYES
• Either by direct emission or by reflection
• Retinal or corneal damage
• Retinal injury
• scotoma

55. SKIN
• Thermal interaction of radiant energy with tissues
• Temperature elevation of 21°C
FACTORS AFFECTING LASER TISSUE INTERACTION
• Relative absorption and transmission
• Pulse duration and repetition rate
• Level of exposure
• Degree of vascularity of tissues

56. Deleterious effects on ENAMEL
Gross cratering from 0.1 – 1.1mm
Under Polarized light- crystallographic changes
Deeper penetration- dark speckling

57. Deleterious effects on DENTIN
• 0.1mm deep irregular craters
Zones of dentinal destruction:
1. Complete dentinal destruction
2. Partial dentinal destruction
3. Scattered zone of dark speckling

58. ELECTRICAL HAZARDS
• High currents and high voltage power supplies
Electrical
hazards
Shock
hazards
Fire
hazards
Explosion
hazards

59. LASER SAFETY

60. LASER SAFETY
SAFETY REQUIREMENTS:
• Laser warning signal
• Barriers
• Eyewear
• High volume suction
• Equipment service
• Protect adjacent tissues

61. 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.

62. References
• Oral laser application. A. MORITZ
• LASER EFFECTS ON DENTAL HARD TISSUES, Adv Dent Res l(l):21-26, O
2002;30(5):342-50.
• Application of Er:YAG and Er,Cr:YSGG Lasers in Cavity Preparation for Dental
Tissues: A Literature Review. World j dent 2012
• Selective ablation of surface enamel caries with a pulsed Nd:YAG dental
laser.Harris DM1, White JM, Goodis H, Arcoria CJ, Simon J, Carpenter WM, Fried
D, Burkart J, Yessik M, Myers T.
• Demineralization of Er:YAG and Er,Cr:YSGG laser-prepared enamel cavities in
vitro. Caries research 37: 34-37, 2003
• Unique aspects of laser energy deposition in the fs pulse regime Michael D.
Feit; Alexander M. Rubenchik; Bruce W. Shore

63. • Lasers and radiofrequency devices in dentistry
Dent Clin N Am 55 (2011) 585-597
• The current status of low level laser therapy in
dentistry. Part 1. soft tissue applications
Australian Dental Journal 1997; 42(4):247-54

64. THANK YOU…….