Lasers in periodontics

INTRODUCTION
HISTORY
PRINCIPLES OF WORKING OF A LASER
FUNDAMENTALS OF LASER
CHARACTERISTICS OF LASER
CLASSIFICATION OF LASER
EFFECTS OF LASER ON SOFT AND HARD TISSUES
VARIOUS LASERS AVAILABLE FOR PERIDONTAL USE
APPLICATION OF LASER TREATMENT IN PERIODONTAL THERAPY
ADVANTAGES & DISADVANTAGES OF LASER IN PERIODONTAL THERAPY
LASER PRECAUTIONS
LASER HAZARDS
RECENT ADVANCES
CONCLUSION

1. LASERS IN PERIODONTICS GUIDED BY Dr K REKHA RANI (PROF & HOD) PRESENTED BY R ANIL KUMAR PG-II

2. CONTENTS INTRODUCTION HISTORY PRINCIPLES OF WORKING OF A LASER FUNDAMENTALS OF LASER CHARACTERISTICS OF LASER CLASSIFICATION OF LASER EFFECTS OF LASER ON SOFT AND HARD TISSUES VARIOUS LASERS AVAILABLE FOR PERIDONTAL USE APPLICATION OF LASER TREATMENT IN PERIODONTAL THERAPY ADVANTAGES & DISADVANTAGES OF LASER IN PERIODONTAL THERAPY LASER PRECAUTIONS LASER HAZARDS RECENT ADVANCES CONCLUSION

3. INTRODUCTION L - Light A - Amplification S - Stimulated E - Emission R - Radiation Lasers have been used extensively in medical field since they were introduced and then Lasers for dental use were introduced.

4. Lasers are the most recent introduction in the treatment of periodontal diseases. Presently, they are used for : Removal of calculus Root surface detoxification Removal of diseased pocket wall and Antimicrobial effect on the pocket micro biota

5. HISTORY 1917- Principle of stimulated emission by Albert Einstein. “Zur Quantum Theory“ 1954- Townes and Gordon- Built microwave laser known as MASER. 1957- Gordon Gould introduced the term LASER. 1960- Theodore Maiman - First LASER- ruby – active medium. 1961- Javan He-Ne laser.( 1 st Gas laser He-Ne laser) 1961- Snitzer – 2 nd Laser i.e., Neodymium doped glass laser

6. 1964- Geusic - developed Nd YAG 1965- Patel - Co2 Laser 1968- Polanyi et al developed articulating arms to deliver co2 laser . 1990 - Ball et al suggested application of ruby laser in opthalmic surgeries 1990 – FDA approved Nd: YAG laser for dental use. Since then many types of lasers including co2 laser, Er: YAG , Diode laser, Er Cr: YSGG has been approved .

7. PRINCIPLES OF WORKING OF A LASER Laser functioning is based on the concepts of probability co-efficient i.e., “Einstein co-efficient” for: Absorption spontaneous emission stimulated emissions of electromagnetic radiation. Absorption: When a photon that has energy equivalent to the difference b/w the two energy levels(E2-E1) is incident on the atom ,the e jumps from ground state (E1) to excited state (E2). It must be noted that absorption of energy (or) light occur only if the energy of the incident photon exactly matches energy difference b/w two energy levels(E2-E1)

8. Spontaneous emission is the process, when electrons transit from a higher energy level (E2) to a lower energy level (E1). These occur naturally & have no control on when it is going to loose energy in the form of light. The photon emitted in spontaneous emission process has “ordinary incoherent light” and do not flow exactly in the same direction of incident photon.

9. The incident photon forces the excited e− to return to ground state. Hence photon energy is supplied to excited e− instead of ground state e−. This results in release of 2 photons:- one photon due to incident photon , other photon is due to the energy release of excited e−. The process of stimulated energy is very fast when compared to spontaneous emissions. Photons emitted during stimulated emission have same energy, frequency, coherent & travels in same directions. Stimulated emission

10. FUNDAMENTALS OF LASER Light is a form of electromagnetic energy that exists as a particle and that travels in waves at a constant velocity. The basic unit of this radiant energy is called a photon. The waves of photons travel at the speed of light and can be defined by two basic properties: Amplitude and wavelength . Amplitude is defined as the vertical height of the wave from the zero axis to its peak as it moves around that axis. wavelength (λ) is defined as the horizontal distance between any two corresponding points on the wave. L IGHT

11. Velocity - Speed of light. Frequency - Number of wave oscillations per second. Frequency is inversely proportional to wavelength: the shorter the wavelength, the higher the frequency, and vice versa.

12. Laser light differs from the ordinary light in the following properties: Monochromatic - one specific color Collimation - a constant size and shape Coherency - have identical wave shapes Efficiency - the clinically useful feature of laser light

13. A MPLIFICATION Amplification is the part of this process that occurs inside the laser. The three components make up the laser cavity: Active medium: Gas lasers ( He:Ne , CO2, excimer [ ArF or KrF ] orargon laser) Solid state lasers ( Nd:YAG , Ho:YAG , Er:YAG , Er,Cr:YSGG , rubin , alexandrite laser) Liquid (dye) lasers (containing liquid colorant as the medium, e.g. Rhodamine G6, Coumarin, etc.) Semiconductor (diode) lasers , so-called GaAs, GaAlAs lasers (containing semiconductor as the medium) “Free-electron” lasers (using an electron accelerator, not available for dentistry)

14. 2. An optical cavity or laser tube having two mirrors on either side. one fully reflective and the other one partially transmissive, which are located at either end of the optical cavity. Acts as resonator helps to amplify & collimate laser beam. 3. An external mechanical, chemical, or optical power source which excites or “pumps” the atoms in the laser medium. Other components are : cooling system & focusing lens etc.

15. R ADIATION Light waves produced by the laser as a specific form of electromagnetic energy. All available dental laser devices have emission wavelengths of approximately 0.5 nm (or 500 nm) to 10.6 nm (or 10,600 nm). They are therefore within the visible or the invisible infrared nonionizing portion of the electromagnetic spectrum and emit thermal radiation.

16. Laser Delivery Laser light should be delivered to the target tissue in a ergonomic and precise manner. Delivery systems….. Articulated arm delivery system Flexible hollow waveguide or tube Glass fiber optic cable Air cooled Glass fiber optic cable

17. Articulated arm delivery system Consist of a series of rigid hollow tubes with mirrors at each joint (called a knuckle) that reflect the energy down the length of the tube. Bulky in size. Disadvantages of Articulated Arm Difficult to remove discrete lesions within the oral cavity-difficult to maneuver the arm. Alignment of the mirrors. Articulated arm delivery systems are noncontact systems.

18. Hollow waveguide or tube Single long, semi- fliexible tube, without knuckles or mirrors. The laser energy is transmitted along the reflective inner lumen of the tube and exits through a hand-piece at the end of the tube.

19. GLASS FIBER OPTIC CABLE For lasers with wavelength shorter than 2500 nm. Cable- More pliant than the waveguide, has a corresponding decrease in weight and resistance to movement, and is usually smaller in diameter Contact fashion or non contact mode.

20. LASER EMISSION MODES Dental Laser can emit light energy in two modalities. 1. Continuous: laser energy is emitted continuously as long as the laser is activated. delivers more energy than pulsed type. Ex: co2 laser , diode laser. 2. Pulsed emission: Free running pulse Gated pulse. Free running pulse: Very large laser energy is emitted for an extremely short span in microseconds, followed by a relatively long time at which the laser is off. Gated pulse: The laser is in an on and off mode at periods. The duration of the on and off timer is in milliseconds. CHARACTERISTICS OF LASER

21. LASER OPERATION PARAMETERS FOCUSED DEFOCUSED Laser beam hits tissue at its focal point narrowest diameter. Beam moved away from its focal point. Cutting mode Wider area of tissue affected as beam diameter increases Ablative mode LLLT 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. Char tissue formation at tip. Tactile feedback is available

22. LASER TISSUE INTERACTION ( Dedrich , 1991) ABSORPTION Most desired interaction by the intended tissue. Tissue characteristics Pigment - Hemoglobin, melanin Water content Chromophores

23. Laser wavelength Emission mode. In general: The shorter wavelengths (from about 500-1000 nm) are readily absorbed in pigmented tissue and blood elements. eg. Argon, Diode and Nd:YAG The longer wavelengths are more interactive with water and hydroxyapatite. e.g. Er:YAG wavelength, C0 2 .

24. The laser beam is simply redirected without having any effect on the tissue. This reflection can be dangerous as the beam could be directed to an unintentional target, such as eyes, and is a major safety concern during the use of lasers. The laser beam passes through the tissue without having any effect on the target tissue. This effect is dependent on the wavelength of laser light.

25. SCATTERING Dispersion of laser beam in to low energy radiations which have no useful biological effects on tissues. Causes an unwanted heat transfers to the adjacents tissues. However, a beam deflected in different directions is useful in facilitating the curing of composite resin or in covering a broad area.

26. EFFECTS OF LASER ON SOFT AND HARD TISSUES The following are the various effects caused by laser beam photons ,when they enter the tissues. ABLATION: When the laser is well absorbed, the energy explodes the target tissue cells & extracellular matrix in a process called ablation. Depends on wavelength & affinity of laser beam for target tissues. FLUORESCENCE: Property of an object of absorbing light of short of short wave length & emitting light of longer wavelength. Ex: fluorescence occurs when carious lesion is exposed to 655nm visible wavelength helps in early diagnosis of carious lesions.

27. PHOTO THERMAL Conversion of laser beam energy in to heat. Use to perform functions such as excision & coagulation. It can be reversible or irreversible depends on the heat produced. Thermal effect of laser on soft tissue: (Donald et al 2005) Tissue Temperature (°C) Observed Effect 37-50 Hyperthermia; bacterial inactivation >60 Coagulation; protein denaturation 70-90 Welding of soft tissue wound edges 100-150 Vaporization > 200 Carbonization; tissue charring

28. PHOTO DISRUPTIVE / PHOTO ACOUSTIC EFFECT This shock wave creates the distinct popping sound while using erbium laser.

29. PHOTOCHEMICAL REACTIONS Photo reactions occur when the photon energy causes chemical reactions, such as the curing of composite resin. The breaking of chemical bonds, such as using photosensitive compounds exposed to laser energy, can produce a singlet oxygen radical for disinfection of periodontal pockets and endodontic canals.

30. PHOTOBIOMODULATION / PHOTOSTIMULATION It used in non contact mode & lower powersetting . It elicit beneficial cellular and biological response. it causes: collagen synthesis , fibroblast proliferation, increased osteogenesis, enhanced leukocyte phagocytosis. Speeds healing , increased circulation & decreased inflammation ,pain.

31. I. According to the wavelength (nanometers) 1. UV (ultraviolet) range – 140 to 400 nm 2. VS (visible spectrum) – 400 to 700 nm 3. IR (infrared) range – more than 700 nm. II. Broad classification 1. Hard laser (for surgical work) i . CO2 lasers (CO2 gas) ii. Nd:YAG lasers (Yttrium- aluminium -garnet crystals dotted with neodymium) iii. Argon laser (Argon ions) 2. Soft laser (for biostimulation and analgesia) He-Ne lasers Diode lasers CLASSIFICATION OF LASERS

32. III. According to the delivery system i . Articulated arm (mirror type) ii. Hollow waveguide iii. Fiber optic cable IV. According to type of lasing medium E.g. Erbium: Yttrium Aluminium Garnet V. According to type of active medium used Gas, solid, semi-conductor or dye lasers VI. According to operation mode 1. Continuous wave lasers 2. Pulsed lasers VII. According to pumping scheme 1. Optically pumped laser 2. Electrically pumped laser

33. Srivastava et al proposed a new simplified classification of lasers based on the clinical use

34. LASERS USED IN PERIODONTICS

35. VARIOUS LASERS AVAILABLE FOR PERIDONTAL USE ARGON WAVE LENGTH:- 488nm (blue) and 514nm (green) WAVE FORM:- Continuous wave or gated pulse DELIVERY FORM:- Flexible fiber optic cable. USE:- for incision and ablation TISSUE REACTION:- preferentially absorbed by pigmented tissue.

36. Application 488nm- used to activate camphoroquinone for the polymerization of composites. 514nm-absorbed by tissues containing hemoglobin, hemosiderin, and melanin. Thus, it has excellent hemostatic capabilities. Acute inflammatory periodontal disease and highly vascularized lesions, such as a hemangioma- ideally suited for treatment by the argon laser. Diagnosis of diseased carious area

37. Neither wavelength is well absorbed in dental hard tissues or in water. The poor absorption into enamel and dentin is advantageous when using this laser for cutting and sculpting gingival tissues because there is minimal interaction and thus no damage to the tooth surface during those procedures. Because of absorption by pigments, it is also absorbed by pigmented bacteria. Henry et al. (1995, 1996) reported that the argon laser at a low level has a bactericidal effect on the Prevotella and Porphyromonas species in the presence of oxygen.

38. DIODE LASER Solid active medium laser. manufactured from semiconductor crystals using combination of aluminum or indium+ gallium + arsenic.

39. WAVE LENGTH – 800 nm-active medium containing aluminum 980 nm- for the active medium composed of indium WAVEFORM - Continuous wave and gated pulsed modes DELIVERY FORM - Fiber optic cable USE:- for soft tissue incision and ablation, gingivectomy ,subgingival curettage. TISSUE REACTION :- low absorption coefficient in water but preferentially absorbed by pigmented tissue. Low-level laser therapy by semiconductor instruments-at lower power- Biostimulation and pain relief.

40. Application Indicated for cutting and coagulating gingiva and oral mucosa, and for soft tissue curettage or sulcular debridement. For caries detection ( Diagnodent , KaVo ), which uses laser fluorescence induced by the 830 nm diode laser. For calculus detection. Advantage- Smaller size of the units as well as the lower financial costs.

41. CO2 LASER One of the oldest lasers Gas-active medium laser - CO 2 + N 2 +He (60 to 80%). WAVELENGTH:- 10,600 nm, DELIVERED SYSTEM:- Articulated arm or Hollow tube-like waveguide EMISSION MODE:- continuous or gated pulsed mode. FOCUSED:- noncontact fashion. Well absorbed by water (second only to the erbium family) therefore is very effective for the surgery of soft tissues, which have a high water content.

42. Advantages Easily cut and coagulate soft tissue, and it has a shallow depth of penetration into tissue, which is important when treating mucosal lesions Useful in vaporizing dense fibrous tissue. The primary advantage of CO2 laser surgery over the scalpel is the strong haemostatic and bactericidal effect. Disadvantages Highest absorption in hydroxyapatite tooth structure of any dental laser. So, soft-tissue surgical site adjacent to tooth must be shielded.

43. The continuous wave emission + delivery system technology of CO 2 devices- limit hard-tissue applications because carbonization and cracking of tooth structure can occur due to the long pulse duration and low peak powers. Since it produces severe thermal damage when applied to hard tissues, its use has been limited to soft tissue procedures.

44. NEODYMIUM: YAG Solid active medium, which is a garnet crystal combined with rare earth elements yttrium and aluminum, doped with neodymium ions. WAVELENGTH :- 1064 nm WAVE FORM:- free running pulsed mode. DELIVERY SYSTEM:- flexible fiber optic. An Nd:YAG laser system Delivery system fiber. Thin flexible fiber can be introduced into the periodontal pocket & grants complete coverage of root surface.

45. Surgical Characteristics- Nd:YAG Highly absorbed by melanin but is less absorbed by hemoglobin than the argon laser and 90% transmitted through water . Slightly absorbed by dental hard tissue, but there is little interaction with sound tooth structure, allowing soft tissue surgery adjacent to the tooth to be safe and precise.

46. common clinical applications are for cutting and coagulating of dental soft tissues and sulcular debridement. Gingivectomy / gingivoplasty . Coagulation of donar site. Frenectomy Excision of pyogen ic granuloma Excision of hemangioma

47. ERBIUM FAMILY There are two distinct wavelengths that use Erbium: Erbium Chromium: YSGG – 2780 nm has an active medium of a solid crystal of yttrium scandium gallium garnet that is doped with erbium and chromium. Erbium: YAG – 2940 nm has an active medium of a solid crystal of yttrium aluminum garnet that is doped with erbium. Delivery system: for Er:YAG it is hollow wave guide or fiberoptic bundle, for Er Cr: YAG it is only fiberoptics. Emission Mode: free running pulse mode. Er: YAG Er, Cr: YSGG

48. Both the wavelength of this family have the highest absorption in water of any dental wave lenght , and a high affinity for HA. 2,940 nm wavelength absorption coefficient of water water evaporates microexplosion of hard tissues

49. Applications include caries removal, cavity preparation, soft tissue surgeries, sulcular debridement, osseous surgery and in implantology.

50. Applications of Lasers IN Periodontal Therapy The application of lasers has been suggested as an adjunctive or alternative tool to conventional periodontal mechanical therapy . Removal of subgingival calculus Root surface alterations Bactericidal and detoxification effects Periodontal pocket treatment Nonsurgical pocket therapy

51. Removal of subgingival calculus Laser now are being used for this procedure. Not only does the laser remove the calculus on the root surface, but it also alters the cementum surface in such a way that it makes it favorable for fibroblast attachment. CO2 laser cannot be used for calculus removal Nd:YAG laser is also basically ineffective for calculus removal The Er:YAG laser is capable of easily removing subgingival calculus without a major thermal change of the root surface in vitro A lower degree of calculus removal with the Er:YAG laser than with scaling and root planing has been noted in vivo study … Eberhard et al.2003

52. Root surface alterations CO2 laser readily carbonizes the root cementum The residual char layer formation which inhibits soft tissue attachment Regarding the Nd:YAG laser , surface pitting and crater formation with charring, carbonization, melting and crater production….. Morlock et al 1992 The Er:YAG laser treated root surface under water coolant has been reported to have a micro-irregular appearance without cracks or thermal side effects ( Aoki et al 2000…)

53. Bacterial reduction It is a simple nonsurgical procedure to eliminate or, at least, reduce the number of viable bacteria in the gingival sulcus. In this procedure a diode laser is used with a thin fiber optic fiber. The only two soft tissue wavelengths that currently meet the criterion of having a delivery system able to deliver laser energy efficiently and effectively to the periodontal pockets for nonsurgical periodontal therapy are Nd:YAG and diode. Both of these wavelengths have been shown to be extremely effective against periodontal pathogens in vivo and in vitro ( Moritz 1998, Pinhero J 1997) These investigators concluded that the diode laser revealed a bactericidal effect, helped reduce inflammation, and supported healing of the periodontal pockets through the elimination of bacteria.

54. AUTHOR AND YEAR Experimental group Control group Conclusion Moritz et al 1997 diode laser + SRP SRP alone High bacterial reduction in SRP + Laser sites than SRP alone sites. Barrajo et al 2004 Diode laser+SRP SRP alone No additional improvement in adjunctive application of laser in comparision to SRP alone. Kreisler et al 2005 Diode laser+SRP SRP alone Greater reduction of PD and increase of attachment gain in adjunctive application of laser .

55. Low-level laser therapy Low level laser energy is responsible for the biomodulatory effects such as - Reduction of discomfort or pain (Kreisler MB, 2004), Promotion of wound healing ( Qadri T,2005) Bone regeneration ( Misra V,1999), Suppression of inflammatory processes ( Qadri T,2005)

56. Low-level laser irradiation enhances the activation of human gingival fibroblasts and periodontal ligament cells to proliferate and release growth factors in vitro ( Kreisler M 2003, Pourzarandian A 2004, Saygun I 2007) Low-level laser therapy decreases the amount of inflammation accelerates wound healing by changing the expression of genes responsible for the production of inflammatory cytokines in vivo ( Safavi SM, 2007)

57. AUTHOR & YEAR STUDY CONCLUSION Elifoncu et al 2017 940 nm diode laser compared with conventional surgery in the management of soft tissue in gingivectomy procedures The diode laser had a great advantage over conventional surgery in the gingivectomy procedures Hadeel et al 2017 diode laser compared with scalpel gingivectomy Diode laser may have some advantages over it Iyamu et al 2013 To compare the use of the 810nm diode laser with conventional surgery in the management of soft tissue mucogingival problems associated with orthodontic treatment. orthodontic patients treated with the diode laser required less infiltration anaesthesia , had reduced bleeding during and after surgery, rapid postoperative haemostasis , elimination of the need for sutures and an improved postoperative comfort and healing

58. Oczelik O et al 2008 , conducted a study to assess the effects of LLLT on healing of gingiva after gingivectomy and gingivoplasty and was concluded that LLLT may enhance epithelization and improve wound healing after gingivectomy and gingivoplasty operations. Kirthichawla et al 2016 , conducted a study to evaluate and compare the effects of low‑level laser therapy (LLLT) on wound healing after depigmentation procedure and was concluded that LLLT promotes wound healing after depigmentation procedure until the 3rd day. On the 7th and 15th day, the difference in healing was not statistically significant

59. Photodynamic therapy Photodynamic therapy or photochemotherapy uses a photoactive dye that is activated by exposed to the light in the presence of oxygen with specific wavelength, forming free radical species that kill target microbes.

60. Photodynamic therapy reduces periodontal disease progression and periodontal tissue destruction in experimentally induced periodontal disease (de Almeida, 2007) In a recent split-mouth clinical study, it was demonstrated that nonsurgical periodontal treatment performed on patients with aggressive periodontitis , by applying photodynamic therapy alone, showed similar clinical improvements in comparison to SRP (de Oliveira RR, 2007)

61. TREATMENT OF DENTIN HYPERSENSITIVITY WITH LASERS It is characterized by short, sharp,pain arising from exposed dentin in response to stimuli typically thermal evaporative tactile, osmotic or chemical and which cannot be ascribed to any other form of dental defect or pathology. The lasers used for the treatment of dentine hypersensitivity are divided in to two groups: Low level lasers like He-Ne, GaAlAs , and Middle output lasers like Nd:YAG and CO lasers. The mechanism of laser effects on dentin hypersensitivity is thought to be the laser induced occlusion or narrowing of dentinal tubules (Lan & Liu 1995), as well as direct nerve analgesia, via pulpal nerve system. It has been hypothesized that the laser energy interferes with the sodium pump mechanism changes the cell membrane permeability and / or temporarily alters the endings of the sensory axons.

62. LASER ROOT CONDITIONING The use of CO2 lasers to decontaminate root surfaces has been investigated, providing more information about the exact power settings and parameters required to avoid root damage. Barone et al . showed that a defocused, pulsed CO2 laser is able to create smooth and clean root surfaces compared to a focused, continuous wave ; the latter leads to melting and root surface damage. Later studies using the same parameters for CO2 lasers reported root conditioning with a better fibroblastic activity, cellular proliferation, and greater fibroblast attachment. In clinical studies and has shown that coronal flap advancement in conjunction with CO2 laser root conditioning leads to improvements in clinical parameters and long‑ term tissue stability after 15 years, compared to the modified Widman periodontal flap procedure.

63. Laser frenectomy Lasers have been used for frenectomy procedures. Studies have shown superiority of laser over the conventional scalpel method which include haemostasis effect , excellent visualization of the operating field, reduce operating time, steriliozation of wound site, elimination of suturing, reduction of postoperative pain & edema and minimal scaring .

64. In comparative study co2 laser shows better intraoperative bleeding control and shorter surgical time while Er,Cr:YSGG laser achieved faster wound healing. Diode lasers are exclusively used for frenectomy because the wavelength of diode laser doesn’t damage the tooth structure. The release of the frenum should be done at 0.8-1.4 watts Continuous Wave (CW) with an initiated disposable tip.

65. Laser depigmentation Gingival and cutaneous melanin pigmentation if often a source of aesthetic problem. It is carried out using non-surgical and surgical procedures. Among the various methods, cryotherapy, gingivectomy and argon laser irradiation. Recently, laser ablation has been recognized as a most effective, pleasant and reliable technique. Many laser systems such as Diode laser, Nd: YAG, CO2, argon laser, Er: YAG laser has been used for depigmentation. The procedure essentially involves removal of gingival epithelium along with a layer of the underlying connective tissue and allowing the denuded connective tissue to heal by secondary intention.

66. Periodontal pocket treatment Conventional mechanical tools are not effective for the complete curettage of soft tissue Nd:YAG laser in a laser-assisted new attachment procedure (LANAP) has been advocated to remove the diseased soft tissue on the inner gingival surface of periodontal pocket underlying connective tissue in vivo. Laser assisted new attachment procedure: LANAP Laser-assisted new attachment procedure (LANAP) is a surgical therapy designed for the treatment of periodontitis through regeneration rather than resection. The primary goal of LANAP is debridement to remove pocket epithelium and underlying infected tissue within the periodontal pocket completely and to remove calcified plaque and calculus adherent to the root surface.

67. Surgical pocket therapy Periodontal surgical procedure to be successful with optimal tissue regeneration, it is necessary for the root surface and bone defect to be completely debrided and decontaminated. 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

68. AUTHOR AND YEAR Experimental group Control group Conclusion Centty et al 1997 OFD+ laser irradiation to outer and inner aspects of mucoperiosteal flap OFD alone Laser eliminated significantly more sulcular epithelium in comparison with conventional periodontal surgery. Gaspirc et al 2007 MWF+laser irradiation to intrabony defects,root surface and flap. OFD alone Adjunctive application of laser showed significantly greater reduction of PD and increase of attachment gain . Crespi et al. used the CO2 laser in a defocused mode (13 W, 40 Hz) for the treatment of experimentally induced Class III furcation defects in dogs following flap surgery and reported that laser treatment promoted the formation of new periodontal ligament, cementum and bone.

69. OSSEOUS SURGERY AND LASERS Erbium Lasers are becoming increasingly popular for bone surgery. More precision & better access. Reduce the risk of collateral damage, particularly when compared with rotary instruments that may become entangled with soft tissues. Markedly reducing the noise and eliminating the vibration associated with the mechanical cutting and grinding of bone tissue. Lack of vibration at the hand piece increases surgical precision. Currently, the Er:YAG laser is safe and useful for periodontal bone surgery in procedures such as osseous removal or recontouring, when used concomitantly with saline irrigation.

70. Post therapy probing intervals Clinician should not reprobe treated sites before 3 months post therapy because healing in the sulcus begins at the bottom of the pocket, which could be damaged with a probe. Probing with a light touch is recommended at 3 months and definitive 6 point probing can be resumed 6 months post therapy. During reevaluation , if the diagnosis indicates areas of active disease, debridement and laser therapy is repeated in all inflamed sites. Reevaluation is done every 3 months for a period of 1 year. This timeline allows for the healing of the treated sites and retreatment of deeper pockets. At 1 year, a decision can be made for surgical intervention, bone grafts or other therapy.

71. Wound healing Advantages of laser vs scalpel surgery Increased coagulation –dry surgical field/better visualisation Tissue surface sterilisation -  in bacteremia swelling ,edema, scarring pain Faster healing response patient acceptance

72. Lasers in Dental Implantology Applications in implant dentistry…. Second stage implant surgery In periimplantitis Osteotomy site preparation

73. Advantages Increased visibility due to hemostasis greater ease in making incisions and contouring soft tissue reduced bacteria at the surgical site The erbium (Er) family of lasers, with its capacity for osseous ablation, can be used in osteotomy preparation and for removal of diseased osseous tissue around areas of inflammation.

74. Implant Placement The Er:YAG laser begins soft tissue preparation. After soft tissue ablation is completed, the surgical site is ready for pilot holes. Er:YAG laser begins osseous preparation . Implant placement with healing caps. Three-month postoperative view

75. Alternate techniques A CO 2 , Nd:YAG , or diode laser can be used to remove soft tissue. The osseous pilot hole can be prepared using either an Er family laser or conventional surgical burs. Even if an Er family laser is used to prepare the pilot hole, enlarging the osteotomy requires conventional implant instrumentation. The diode, Er family, and CO 2 lasers can be used for specific procedures such as removing soft tissue covering the integrated implant. ( Kreisler M, 2002 Yeh S, 2005) Er lasers can be used to remove and recontour bone safely and effectively and to help prepare edentulous sites for implant placement. ( Bach G, 2000) (Kreisler M, 2002) (Deppe H, 2002) ( Stubinger S, 2005)

76. SECOND STAGE IMPLANT SURGERY

77. Peri-implantitis Treatment The term periimplantitis, describes the bone loss around an implant. Conventional mechanical instruments, such as steel curettes or ultrasonic scalers, are not completely suitable for granulation tissue removal and implant surface debridement because they readily damage the implant titanium surfaces and thus may interfere with the process of bone healing. Among the lasers applied in dentistry, the Er:YAG laser is considered to possess the best property for both degranulation and implant surface decontamination as a result of its dual actions of both soft and hard tissue ablation without causing thermal damage of the adjacent tissue.

78. CO 2 laser and Diode Laser- demonstrated effective decontamination of the implant surfaces without excessive temperature elevation Kato et al, 2003, Deppe et al, 2001, 2007, Stubinger et al, 2005 Er: YAG Laser- more suitable for promoting re-osseointegration than the plastic curet instrumentation plus antibiotic & ultrasonic scalers (Schwarz et al 2006) Although a promising field, further long term studies are required for the application of laser in implant maintenance therapy.

79. Less pain Less need for anesthetics (an advantage for medically compromised patients) No risk of bacteremia Excellent wound healing; no scar tissue formation Bleeding control (dependent on the wavelength and power settings); Usually no need for sutures Use of fewer instruments and materials and no need for autoclaving (economic advantages) Ability to remove both hard and soft tissues Lasers can be used in combination with scalpels (however, the laser is a tool and not a panacea) Advantages of using lasers in the periodontal therapy

80. Laser light interact with target tissue not only with contact irradiation mode but also in non contact irradiation mode. There fore use of glasses for eye protection( by the patient ,operator and assistant) is required. Extreme temperature levels of ≥60°C (140°F) result in tissue necrosis. Relatively high cost of the devices A need for additional education (especially in basic physics) Every wavelength has different properties. Disadvantages of using lasers in periodontal therapy.

81. DENTAL LASER SAFETY Laser Hazard Classification according to OSHA Standards: Class I - Low powered lasers that are safe to view Class IIa - Low powered visible lasers that are hazards only when viewed directly for longer than 1000 sec. Class IIb - Low powered visible lasers that are hazardous when viewed for longer than 0.25 sec. Class IIIa - Medium powered lasers or systems that are normally not hazardous if viewed for less than 0.25 sec without magnifying optics. Class IIIb - Medium powered lasers (0.5w max) that can be hazardous if viewed directly. Class IV - High powered lasers (>0.5W) that produce ocular, skin and fire hazards.

82. Ocular injury: Injury to eye occur either direct emission from the laser or reflection from a mirror. Tissue damage: Laser includes damage to skin and other nontarget tissue which results in thermal interaction. Above the normal temperature can produce cell destruction by denaturation of cellular enzymes and structural proteins. Environment: Inhalation of airborne biohazardous material which results in the application of laser chemical like methane, benzene, formaldehyde present in the laser which can injuries if inhaled. Combustion hazards: Flammable gas, solid, liquids used within the clinical setting can be easily ignited if expose to a laser beam. Electrical Hazards: This is due to very high currents and high voltage required to use the present dental lasers. These can be electrical shock hazards or electrical fire or explosion hazards The types of hazards can be grouped as follows

83. SAFETY PRECAUTIONS Use glasses for eye protection (patient, operator, and assistants). Prevent inadvertent irradiation (action in noncontact mode). Protect the patient’s eyes, throat, and oral tissues outside the target site. Use wet gauze packs to avoid reflection from shiny metal surfaces. Ensure adequate high speed evacuation to capture the laser plume.

84. RECENT ADVANCES WATERLASE SYSTEM Waterlase system is a revolutionary dental device that uses laser energized water to cut or ablate soft and hard tissue. WaterLase iPlus : 2,780nm YSGG and 940nm diode ($ 16900) WaterLase MDX: Er;Cr:YSGG , 2780 nm iLase - $24950

85. Perio wave Periowave is a photodynamic disinfection system utilizes nontoxic dye (photosensitizer) in combination with low intensity lasers enabling singlet oxygen molecules to destroy bacteria. The most important recent development in laser dentistry is the advent of the Er,Cr:YSGG laser, which is used with a water spray ( Hydrophotonics effect).

86. PerioLase MVP-7 Dental Laser The PerioLase MVP-7, an optimized free-running Nd:YAG laser, used for LANAP: LASER ASSISTED NEW ATTACHMENT PROCEDURE LAPIP:LASER ASSISTED PERIIMPLANTITIS PROCEDURE LAPIP:LASER ASSISTED PERIIMPLANTITIS PROCEDURE LAPIP is a cutting-edge laser treatment to save failing dental implants. Preformed by using the MVP periolase Dental laser. The treatment involves disinfecting the dental implant and creating a healing clot around the dental implants, which calls on your body‟s healing ability to produce bone around the implant and and in essence stabilizes the implant.

87. CONCLUSION Considering the various advantages of the laser irradiation, its use in combination with conventional mechanical treatment or alone has the potential to improve the condition of the periodontal pockets more than mechanical therapy alone Based on the limited research so far, the Er: YAG holds promise to debride both the root surface and soft tissue wall of the pocket, and the Nd: YAG, diode, Ar have a potential for the soft tissue curretage

88. References Charles M. Cobb. Lasers in Periodontics: A Review of the Literature. J Periodontol April 2006 Slot DE, Kranendonk AA, Paraskevas S, Van der Weijden F. The Effect of a Pulsed Nd:YAG Laser in Non-Surgical Periodontal Therapy. J Periodontol 2009;80:1041-1056. Raffetto N. Lasers for initial periodontal therapy. Dent Clin N Am 48 (2004) 923-936. Coleton S. Lasers in surgical periodontics and oral medicine. Dent Clin N Am 48 (2004) 937-962 Martin E. Lasers in dental implantology. Dent Clin N Am 48 (2004) 999-1015

89. Gaspirc B, Skaleric U. Clinical evaluation of periodontal surgical treatment with an Er:YAG laser: 5-year results. J Periodontol . 2007 Oct;78(10):1864-71. Yukna RA. Histologic evaluation of an Nd:YAG laser-assisted new attachment procedure in humans. Int J Periodontics Restorative Dent. 2007 Dec;27(6):577-87. Lasers in nonsurgical periodontal therapy. Periodontology 2000, Vol. 36, 2004, 59–97 Application of lasers in periodontics: true innovation or myth? Periodontology 2000, Vol. 50, 2009, 90–126.