1. Laser in Dentistry
By Hisham Sindi

2. LASER
Light Amplification by Stimulated Emission of Radiation

3. Stimulated VS. Spontaneous

4. Production of Laser Energy
Active Medium
Optical Resonator
Energy Source

5. 1) Active Medium Solid : (ruby and Nd: YAG)
Gas : (CO2, argon and He-Ne)
Liquid : (complex organic dyes)
Semiconductor : (diodes)
Metal vapor : (copper)

6. 2) Optical Resonator Left mirror : Flat and full reflection
Right mirror : Concave and partial transmition

7. Energy Source High Voltage Power Supply Radiofrequency Generator
Flash Lamp Tube
Another laser

8. Active medium
Energy source
Left mirror
Right mirror
Laser

11. Characteristics
Coherent
Parallel
Monochromatic

12. Classification of Laser
Medium
Heat production
Output power
Pumping scheme
Operation mode

13. According to Heat Production
1) Athermic (Soft laser) (LLL) :
He-Ne
2) Thermic (Hard laser) :
CO2
Nd:YAG
Ruby

14. According to Output Power
Low power : (up to 1000 mW)
Middle power : (1-3 W)
High power laser : (3 W and upwards)

15. According to Pumping Scheme
Optical
Electrical

16. According to The Operation Mode
Continuous wave
Pulsed

17. Uses of Laser
Commercial
Industrial
Medical
Research
Military

18. 1) Commercial Copiers Displays Communications Printing Scanning
Light shows
Compact Disk (CD)

19. 2) Industrial Alignment Cutting Drilling Sealing Construction
Soldering

20. 3) Medical Ophthalmology Invasive Surgery Dentistry Diagnostic
Cosmetic Surgery
Endoscopy

21. 4) Research
Fusion
Spectroscopy
Velocimetry

22. Military
Navigation
Ranging
Illumination
Weapons

23. Biologic effects of Laser Light
Thermal effect:
Photocoagulation
Photovaporization
2) Non thermal effect:
Photochemical
Photomechanical

24. Thermal Effect 36.5 C˚: No effect 37 C˚ : Photoactivation
44 C˚ : Tissue denaturation
60 C˚ : Tissue degradation
Whitening of tissue surface
65 C˚ : Tissue coagulation
Hemostasis and Intraluminal thrombosis
Exceeding 100 C˚ : Vaporization

25. Sizes of Cutting Depend on:
Thermal conduction of the tissue
The wave length
The power of energy

26. Non Thermal Effect Photochemical : Neural Activation of enzymes (ATP)
Cell membrane
2) Photomechanical (Nd-YAG) :
Extremely high power ultra short pulses.

27. Laser in Dentistry

28. Pulsed Nd-YAG Lasers 1) Soft tissue : Gingival retraction Gingivectomy
Gingivoplasty
Frenectomies
Apthus ulcers
2) Hard tissue:
Enamel and dentin etching
Dentin Hypersensitivety
Caries detection
Endodontic treatment (shaping, sterilization and obturation)

29. Argon Lasers (476, 488, 514 nm)
Cure dental bonding agent and composite resin.
Recommended for many soft tissue application

31. CO2 Lasers (10600 nm) Superficial cutting or vaporizing soft tissue.
Oral and maxillofacial surgery
Minimal photocoagulation in deeper tissues

32. Er-YAG Lasers Strongly absorbed by collagen, hydroxyapatite and water
Caries removal and cavity preparation
Hard dental tissue
Cut and vaporize with small zones.

33. Effects of Lasers on Dental Tissues
Enamel
Dentin
Cementum
Pulp
Wound healing

34. Effect on Enamel Modification of the enamel surface
Melting structural elements
Increase caries resistance

35. Effect on Dentin Sealing of dentinal tubules
Decrease dentin permeability
Desensitization of dentin

36. Effect on Cementum Increase resistance
Reduction of plaque accumulation
Calculus removal

38. Effects in Wound Healing
Rapid epithelization
Increase collagen
Neovasculrization
Neural regeneration
Haemostatsis

39. Safety Measures Protective glasses Cover reflective surfaces
Wet gauze pads
Remove anesthetic gases
Suction smoke and vaporized soft tissue

40. Contraindications
Pregnancy
Heart diseases

41. Examples
Diagnodent
Waterlase

42. Thank You