Laser in dentistry 1 SUD.pptx in periodontics

Laser in dentistry 1 SUD.pptx in periodontics

1. LASERIN DENTISTERY 1

2. OBJECTIVES By the of this lecture the student must be able: 1- To define laser 2- To outline advantage and disadvantage of laser 3- To list potential application of laser in dentistry and periodontal therapy 4- To outline precautions and risk associated with clinical use of laser 19/09/2022 2

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4. Common Components of all Lasers 1- Active Medium May be Solid  crystals such as ruby or Nd:YAG , Liquid  such as dyes Gases  like CO2 or Helium/Neon Semiconductors  such as GaAs . Active mediums Contain atoms whose electrons may be excited to a metastable energy level by an energy source. 19/09/2022 4

5. 2- Excitation Mechanism Excitation mechanisms pump energy into the active medium by one or more of three basic methods; Optical Electrical Chemical. 3- High Reflectance Mirror A mirror which reflects essentially 100% of the laser light. 4- Partially Transmissive Mirror A mirror which reflects less than 100% of the laser light and transmits the remainder. 19/09/2022 5

6. Block diagram of laser system 19/09/2022 6

7. Unique Properties Of Lasers: Laser light has unique properties compared with other light sources. These properties are: 1 – Monochromaticity , The color of the light is determined by the length of its waves ( λ ). Laser light is single colored light (has one λ , or monochromatic). Each type of lasers has single wavelength. 19/09/2022 7

8. Light bulb laser Fig.13 19/09/2022

9. 2 – DIRECTIONALITY: All conventional light sources emit light in this manner. The beam produced always diverges (spreads) more rapidly than the beam generated by a laser. Fig. 14 Conventional light source 19/09/2022 9

10. Fig. 15 Directionality of laser light "Directionality" is the characteristic of laser light that causes it to travel in a single direction within a narrow cone of divergence. 19/09/2022 10

11. 3 – Coherence: All the photons in any laser light are coherent , i.e. they are in phase , while photons in other light sources have no relation between them, i.e. they are out of phase . This light is said to be " incoherent,". 19/09/2022 11

12. Fig. 16 Incoherent light waves 19/09/2022 12

13. All of these individual waves are in step, or "in phase," with one another at every point. "Coherence" is the term used to describe the in-phase property of laser beam. Fig. 17 Coherent light waves 19/09/2022 13

14. 4- Intensity Laser light is the intense light ever be known. Each laser type has its own intensity which can be defined as the number of photons emitted per unit surface area per unit solid angle. Even lasers with low intensity, compared with other lasers, are intense more than the sun light. This property is due to huge number of coherent photons emitted with very small angle (little divergence) ) 19/09/2022 14

15. Types of lasers Lasers may be classified according to the type of: Active medium Excitation mechanism Region of emitted wavelength Mode of operation. 19/09/2022 15

16. According to the active medium, lasers are classified to: Solid, gas, liquid and semiconductor lasers. According to the spectral region of the emitted laser, the classification is : UV, visible and infra red (I.R) lasers. 19/09/2022 16

17. Electromagnetic Spectrum 19/09/2022 17

18. Based on the mode of operation lasers are classified to : C ontinuous wave (CW), chopped, pulsed and ultra short pulsed lasers. Output power P Time Fig.18 : relation between laser power and operation time in CW lasers 19/09/2022 18

19. Output power P Time Fig.19 : relation between laser power and operation time in chopped lasers 19/09/2022 19

20. Pulse energy Pulse width Peak power Output power Time Pulsed Lasers Ultra Short Pulsed Lasers 19/09/2022 20

21. Delivery systems Free beam Optical fiber Articulated arm Lens 19/09/2022 21

22. The basic phenomena always accompanying the light-tissue interaction. When A photon strikes the tissues 19/09/2022 22

23. Mechanisms of laser interaction with human tissues Classification Types of interactions those that are developed with tissue : low photochemical Medium photothermic Greater Photofragmentation 19/09/2022 23

24. Selective absorption of laser light by human tissues Selective absorption occurs when a given color of light is strongly absorbed by one type of tissue, while transmitted by another. Lasers’ pure color is responsible for selective absorption. 19/09/2022 24

25. The main absorbing components of tissues are: Oxyhemoglobin (in blood) Melanin Water Selective absorption of laser light by human tissues Oxyhemoglobin (in blood) The blood’s oxygen carrying protein absorption of UV and blue and green light, 19/09/2022 25

26. Melanin (a pigment in skin, hair, etc): absorption in visible and near IR light (400nm – 1000nm), Water (in tissues) Transparent to visible light but strong absorption of UV light below 300nm and IR over 1300nm 19/09/2022 26

27. Applications of Lasers in Dentistry 1. Diagnosis Detection of pulp vitality Doppler flowmetry Laser fluorescence- Detection of caries, bacteria and dysplastic changes in the diagnosis of cancer 2. Hard tissue applications Caries removal and cavity preparation Re-contouring of bone (crown lengthening) Endodontic (root canal preparation ,sterilization and Apicectomy) Laser etching Caries resistance 19/09/2022 27

28. 3. Soft tissue applications Laser-assisted soft tissue curettage and peri -apical surgery Bacterial decontamination Gingivectomy and Gingivoplasty Gingival retraction for impressions Implant exposure Biopsy incision and excision Treatment of aphthous ulcers and Oral lesion therapy Coagulation / Hemostasis Tissue fusion - replacing sutures Laser-assisted flap surgery Removal of granulation tissue Pulp capping, Pulpotomy and pulpectomy Operculectomy and Vestibuloplasty Incisions and draining of abscesses Removal of hyperplastic tissues and Fibroma 19/09/2022 28

29. 4. Laser-induced analgesia 5. Laser activation Restorations (composite resin) Bleaching agents 6. Other Removal of root canal filling material and fractured instrument Softening gutta-percha Removal of moisture/drying of canal 19/09/2022 29

30. Lasers in Surgical therapies The advantages of lasers over conventional surgical procedures as: Dry and bloodless surgery Instant sterilization of the surgical site Reduced bacteremia Reduced mechanical trauma Minimal postoperative swelling and scarring Minimal postoperative pain High patient acceptance less need for suturing and faster healing 19/09/2022 30

31. LNAP (laser new attachment procedure): Subgingival curettage: Minor surgeries: Nonosseous gingival surgeries, like frenectomy, frenotomy, gingivectomy, gingivoplasty and operculectomy can be performed. Biopsy and excision of soft tissue pathologies De-epithelialization: Osseous recontouring: Removal of granulation tissue: Periodontal regeneration surgery: 19/09/2022 31

32. Lasers in esthetic surgeries Depigmentation: Crown lengthening/soft tissue management around abutments Formation of ovate pontic sites and modification of soft tissue around laminates Bleaching Graft retrieval from palate 19/09/2022 32

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34. frenectomy 19/09/2022 34

35. Gingivectomy and pocket sterilization 19/09/2022 35

36. depigmintation 19/09/2022 36

37. bleaching 19/09/2022 37

38. Any Questions? 19/09/2022 38

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40. photodynamic therapy Antimicrobial photodynamic therapy uses a photosensitizer (nontoxic dye), which specifically targets microorganisms and is activated by low-level laser light . The introduction of a photosensitizer can greatly increase the bactericidal ability of a laser. 19/09/2022 40

41. low level laser therapy (LLLT) The principle of using low level laser therapy (LLLT) is to supply direct bio stimulative light energy to body cells . Absorbed laser energy causes stimulation of molecules and atoms of cells . Using low-intensity laser radiation on the tissues does not cause rapid and significant increase in tissue temperature. 19/09/2022 41

42. Among various lasers used for periodontal purposes, semiconductor diode lasers are mainly applied in subgingival curettage and periodontal pocket disinfection. So far, a concerted effort has been made in the field of root conditioning to improve the outcome of regenerative periodontal therapies by favoring the attachment of the regenerated periodontal structures 19/09/2022 42

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45. Advantages of laser treatment in periodontics are : Effective and efficient soft and hard tissue ablation A greater hemostasis Bactericidal effect Minimal wound contraction Faster bone tissue healing Minimal collateral damages With reduced use of local analgesia. 19/09/2022 45

46. Types of Laser Hazards Eye : Acute exposure of the eye to lasers of certain wavelengths and power can cause corneal or retinal burns (or both). Chronic exposure to excessive levels may cause corneal or lenticular opacities (cataracts) or retinal injury. Skin : Acute exposure to high levels of optical radiation may cause skin burns ; while carcinogenesis may occur for ultraviolet wavelengths (290-320 nm). Chemical : Some lasers require hazardous or toxic substances to operate (i.e., chemical dye, Excimer lasers). Electrical : Most lasers utilize high voltages that can be lethal. Fire : The solvents used in dye lasers are flammable. High voltage pulse or flash lamps may cause ignition. 19/09/2022 46

47. Laser Hazard Classes The ANSI Laser Safety standard has defined Laser Hazard Classes , which are based on the relative dangers associated with using these lasers. Class 1 Class 2 Class 3a Class 3b Class 4 Most Hazardous Least Hazardous 19/09/2022 47

48. Class 1 Lasers This class cannot produce a hazardous beam because it is of extremely low power, or because it has been rendered intrinsically safe due to the laser having been completely enclosed so that no hazardous radiation can escape and cause injury. 19/09/2022 48

49. Class 2 Lasers These lasers are visible light (400-760 nm) continuous wave or pulsed lasers which can emit energy greater than the limit for Class I lasers and radiation power not above 1 mW . This class is hazardous only if you stare directly into the beam for a long time, which would be similar to staring directly at the sun. Because class 2 lasers include only visible wavelengths, the aversion reaction will usually prevent us from permanently damaging our eyes. The aversion reaction refers to our tendency to look away from bright light. 19/09/2022 49

50. Class 3a Lasers This class of intermediate power lasers includes any wavelength. Only hazardous for intrabeam viewing. This class will not cause thermal skin burn or cause fires. 19/09/2022 50

51. Class 3b Lasers Visible and near-IR lasers are very dangerous to the eye Pulsed lasers may be included in this class. This class will not cause thermal skin burn or cause fires. Requires a Laser Safety Officer and written Standard Operating Procedures. 19/09/2022 51

52. Class 4 Lasers These high-powered lasers are the most hazardous of all classes. Even a diffuse reflection can cause injury. Visible and near-IR lasers will cause severe retinal injury and burn the skin . Even diffuse reflections can cause retinal injuries. UV and far-IR lasers of this class can cause injury to the surface of the eye and the skin from the direct beam and specular reflections . This class of laser can cause fires . Requires a Laser Safety Officer and written Standard Operating Procedures. 19/09/2022 52

53. Control Measures There are several measures that can be taken to prevent injury from lasers. These measures include: Engineering Controls Administrative Controls Personnel Protective Equipment Warning Signs and Labels 19/09/2022 53

54. Laser Warning Signs “ DANGER ” indicates a very dangerous situation that could result in serious injury or death. This sign should be used for Class 3b and 4 lasers. “ CAUTION ” indicates a potentially hazardous situation which could cause a less serious injury. This sign should be used for Class 2 and 3a lasers. “ NOTICE ” does not indicate a hazardous situation. This sign should only be used to make people aware of facility policies regarding laser safety and/or to indicate that a repair operation is in progress. 19/09/2022 54

55. “CAUTION” Warning Sign CAUTION Laser Class and system go here Type of Laser, emitted wavelength, pulse duration, and maximum output go here Safety Instructions may include: Eyewear Required Invisible laser radiation Knock Before Entering Do Not Enter When Light is On Restricted Area Safety Instructions go here 19/09/2022 55

56. “DANGER” Warning Sign DANGER Laser Class and system go here Type of Laser, emitted wavelength, pulse duration, and maximum output go here Safety Instructions may include: Eyewear Required Invisible laser radiation Knock Before Entering Do Not Enter When Light is On Restricted Area Safety Instructions go here 19/09/2022 56

57. “NOTICE” Sign for Laser Repair NOTICE Safety Instructions go here (such as “Laser Repair in Progress”) Laser Class and system go here Type of Laser, emitted wavelength, pulse duration, and maximum output go here Safety Instructions may include: Eyewear Required Invisible laser radiation Knock Before Entering Do Not Enter When Light is On Restricted Area “NOTICE” Sign for Laser Repair 19/09/2022 57

58. Any Questions? 19/09/2022 DR SAHAR ABDELATIF ABDELRHMAN 58