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Dental Tribune Middle East & Africa Edition | 5/2016 9 mCME ◊Page8 mCMESELFINSTRUCTIONPROGRAM CAPPmea together with Dental Tribune provides the opportunity with its mCME - Self Instruction Program a quick and simple way to meet your continuingeducationneeds.mCMEoffersyoutheflexibilitytoworkatyour own pace through the material from any location at any time. The content is international, drawn from the upper echelon of dental medicine, but also presentsaregionaloutlookintermsofperspectiveandsubjectmatter. Membership YearlymembershipsubscriptionformCME:1,100AED OneTimearticlenewspapersubscription:250AEDperissue.Afterthe payment,youwillreceiveyourmembershipnumberandallowingyouto starttheprogram. 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Formoreinformationpleasecontactevents@cappmea.comor +97143616174 FORINTERACTIONWITHTHEAUTHORSFINDTHECONTACTDETAILSAT THEENDOFEACHARTICLE. nanometer (nm). Waves rise and fall around the zero axis many times a second, referred to as oscillations, and the number of oscillations per second is the frequency, measured in hertz (Hz). The laser utilized in the treatment of this case (Er,Cr:YSSG) functions at a wavelength 2780 nm, and at a frequency of 1 – 100 Hz. Hertz also states the number of laser pulses per second of emitted energy. Toputthesepropertiesintoperspec- tive, light from a household bulb is white and diffuse, it is not focused. Laser light differs in that it is mono- chromic (a beam of single colour), and that its waves are coherent. This means they are identical in size and shape. The amplitude as well as the frequency of all the waves of pho- tons are identical. The production of focused electromagnetic (EM) ener- gy is a direct result of this coherence. Whilst a 100Watt bulb may light a room, a 2Watt laser may perform a surgical excision, since all the pho- tonsinthelaserlightarefocusedand “work together”.12 A laser consists of three structural components, name- ly the active medium, the pumping mechanism, and the optical resona- tor (Figs. 7a, b). In-depth electromag- netism physics may not be essential knowledge for the clinician, but it may be helpful to know that lasers derive their product nomenclature from these components. The active medium may consist of a container of gas (CO2 lasers), a solid crystal (Er,Cr:YSSG laser), a solid-state semi- conductor(diodelaser),orasaliquid. The active medium is surrounded by the pumping mechanism which is an excitation source (source of en- ergy, electric coil, lamp strobe, etc.). The excitation source will excite electrons, and as they return to their resting state they emit energy in the formofphotons. Completing the laser cavity are op- tical resonators (typically mirrors) that reflect waves back and forth, thereby collimating and amplifying the beam.12 As with normal light, the clinician may note that laser light wavesexistontheEMspectrumand can correlate the type of laser to its respective wavelength (Fig. 8 ). All commercially available dental lasers emit light and wavelengths ranging 500 – 10,000 nm.13 As such, a dental laser may fall within the visible or invisible and nonionizing range of the EM spectrum. An erbium laser for example then may have an ad- ditional light source in the device for the clinician to visualize the applica- tionpoint. Furthermore, the point of caution here is that all persons in the laser operatingroomaretowearlaserpro- tectiveeyewear. When the laser is activated there may be four possible interactions between the laser light and the tar- get area, depending on the tissues’ optical properties, depending on the light’s wavelength.10 Reflection will occur when the light is deflected off the surface, with no effect. This may be of consequence to neighbouring, absorbing tissues, and may cause injury to a nearby person’s unpro- tected eyes. The laser light may also be transmitted, again with no effect on the target tissue, but possible unintended or detrimental effect to neighbouring tissue. Absorp- tion may be the most desired effect. The amount of absorption further depends on the tissue’s water con- tent, and pigmentation. The fourth interaction is scattering, whereby the photons penetrating the tissue change directions and leads to ab- sorption in a greater area. As laser energy is absorbed by the tissue the interaction is photothermal (laser energy transformed into thermal energy). The effects then are either incision/ excision, ablation/vapori- zation, or hemostatic/coagulation.14 When the beam’s spot size (diam- eter) is small and focused, it is suited for an incision/excision procedure. A wider beam size will interact with thetissuemoresuperficiallyproduc- ing surface ablation. And when the beam is out of focus or less focused coagulation can be performed. In the treatment of this gingival hy- perpigmentation case, a larger beam diameter allowed for superficial tis- sue interaction but deep enough to target the basal and suprabasal epithelial layers rich in melanocytes. The ablative action of the laser over a wider area allowed for removal of the superficial gingival layers rather than focused cutting. Oral mucosa is high in water content and the la- ser’s effect primarily involves the thermal change in the tissue. When watertemperatureisraisedto100°C vaporization of the water within the mucosa occurs, called ablation. Inci- sion and excision of oral soft tissues occurs at this temperature. Between 60° and 100° C proteins will dena- ture without vaporization of under- lying tissue, ideal for the removal of diseased degranulation tissue, for hemostasisandcoagulation.15 Charring of the tissues will however occur at temperatures at around 200° C.16 When removing hyperpig- mented tissues, lower temperatures are needed, and much less energy is needed since chromophores attract lasers. Conversely, higher energy would be needed to excise fibrotic tissuewithlesschromophores.17 Lasers used for the aesthetic cor- rection of physiological hyperpig- mentation have been extensively described in the literature, and sug- gested as superior to other treat- ments due to the fast healing, re- duced pain and discomfort, clean and dry operating field, and stable results.1,19,20,21 The formation of pro- tein coagulum on the laser treated wound surface reduces postopera- tive pain. Laser light may also “seal” free nerve endings.18 The patient treated in the case presented here required only 1 ampoule local anaes- theticinfiltrationperquadrantdeliv- ered segmentally across the working area. The operating field was dry and void of any profuse bleeding. Nearly the entirety of the hyperpigmented le- sions had the superficial layers of tissue layers removed. Healing was rapid with no report of pain, infec- tion,nordiscomfort. At as early as 10 days postoperative the area was nearly entirely healed with radical results in tissue colour and contour. The literature reports the expected chronological and degrees of repigmentation follow- ing removal by various modes of treatment. Depigmentation by laser rankslow(1.16%)intermsofpercent- agerepigmentation(Table2). Conclusion Er,C r:YSSG laser therapy for de-epi- thelialization can successfully alter blue – black/dark brown gingiva to uniform pink colour with numer- ous benefits for both clinician and patient. The results can be dramatic for patients seeking this treatment, remainingstableoverthelong-term, contributing greatly to an aestheti- callypleasingsmile. References 1. Lin YH, Tu YK, Lu CT, Chung WC, Huang CF, Huang MS, et al. ystemat- ic review of treatment modalities for gingival depigmentation: a random- effects p oisso n regression analysis. J EsthetRestorDent.2014;26(3):162-78. 2. Fiorellini JP, Kim DM, Uzel NG. Anatomy of the periodontium. In: Newman MG, Takei HH, Klokkevold PR, Carranza FA, editors. Carranza’s Clinical Periodontology. St. Louis: El- sevier;2012.p.12–27. 3. Fiorellini JP, Kim DM, Uzel NG. Clinical features of gingivitis. In: Newman MG, Takei HH, Klokkevold PR, Carranza FA, editors. Carranza’s Clinical Periodontology. St. Louis: El- sevier;2012.p.79-80. 4. Bakhshi M, Rahmani S, Rahmani A. Lasers in esthetic treatment of gingival melanin hyperpigmenta- tion: a review article. Lasers Med Sci. 2015;30(8):2195-203. 5. Peeran SW, Ramalingam K, Peeran SA, Altaher OB, Alsaid FM, Mugrabi MH. Gingival pigmentation index proposal of a new index with a brief review of current indices. Eur J Dent 2014;8:287-90. 6. Sulewski JG. Einstein’s “Splendid Light”: Origins and Dental Applica- tions. In: Convissar RA. Principles and Practice of Laser Dentistry. 2nd ed. St. Louis: Mosby Elsevier; 2015. p. 7. 7. Coluzzi DJ, Convissar RA, Roshkind DM. Laser Fundamentals. In: Con- vissar RA. Principles and Practice of Laser Dentistry. 2nd ed. St. Louis: MosbyElsevier;2015.p.12–26. 8. Taylor R, Shklar G, Roeber F. The effects of laser radiation on teeth, dental pulp, and oral mucosa of ex- perimental animals. Oral Surg Oral MedOralPathol.1965,;19(6):786–795. 9. Hamblin MR, Huand YY. Hand- book of Photomedicine. Boca Raton: CRCPress;2013. 10.ShanelecDA,TibbettsLS,Ishikawa I, Butler B, Akira Aoki, McGregor A, et al. Recent Advances in Surgical Tech- nology. In: Newman MG, Takei HH, Klokkevold PR, Carranza FA, editors. Carranza’s Clinical Periodontology. St.Louis:Elsevier;2012.p.606. 11. The photonics dictionary. 43rd ed. Pittsfield:LaurinPublishing;1997. 12.MyersTD.Lasersindentistry.JAm DentAssoc.1991;122(1):46-50. 13. Parker S. Surgical lasers and hard dental tissue. Br Dent J. 2007;202(8):445-54. Figure 7:(a) Components of a gas or solid active-medium laser, eg. CO2 or Nd:YAG laser, and (b) a diode laser. Adapted from Principles and Practice of Laser Dentistry 2nd ed (p. 14),byConvissarRA,2015,St.Louis:MosbyElsevier Figure 8:Wavelengths of the various laser lights and their position within the EM spec- trum.AdaptedfromPrinciplesandPracticeofLaserDentistry2nded(p.14),byConvissar RA,2015,St.Louis:MosbyElsevier Table 2: Literature review 1951 – 2013; pigmentation recurrence rates (%) by random- effectsPoissonregression1 G L U C K M A N / D U T O I T 12 INTERNATIONAL DENTISTRY – AFRICAN EDITION VOL. 6, NO. 1 reduces postoperative pain. Laser light may also “seal” free nerve endings.18 The patient treated in the case presented here required only 1 ampoule local anaesthetic infiltration per quadrant delivered segmentally across the working area. The operating field was dry and void of any profuse bleeding. Nearly the entirety of the hyperpigmented lesions had the superficial layers of tissue layers removed. Healing was rapid with no report of pain, infection, nor discomfort. At as early as 10 days postoperative the area was nearly entirely healed with radical results in tissue colour and contour. The literature reports the expected chronological and degrees of repigmentation following removal by various modes of treatment. Depigmentation by laser ranks low (1.16 %) in terms of percentage repigmentation (Table 2). Conclusion Er,Cr:YSSG laser therapy for de-epithelialization can successfully alter blue – black/dark brown gingiva to uniform pink colour with numerous benefits for both clinician and patient. The results can be dramatic for patients seeking this treatment, remaining stable over the long-term, contributing greatly to an aesthetically pleasing smile. References 1. Lin YH, Tu YK, Lu CT, Chung WC, Huang CF, Huang MS, et al. Systematic review of treatment modalities for gingival depigmentation: a random-effects poisson regression analysis. J Esthet Restor Dent. 2014;26(3):162-78. 2. Fiorellini JP, Kim DM, Uzel NG. Anatomy of the periodontium. In: Newman MG, Takei HH Carranza’s Clinical Per p. 12 – 27. 3. Fiorellini JP, Kim DM, Newman MG, Takei HH Carranza’s Clinical Per p. 79 - 80. 4. Bakhshi M, Rahmani gingival melanin hyperpig 2015;30(8):2195-203. 5. Peeran SW, Ramalin Mugrabi MH. Gingival p with a brief review of curre 6. Sulewski JG. Einste Applications. In: Convissar 2nd ed. St. Louis: Mosby E 7. Coluzzi DJ, Convissa Convissar RA. Principles a Louis: Mosby Elsevier; 201 8. Taylor R, Shklar G, Ro dental pulp, and oral muco Med Oral Pathol. 1965,;1 9. Hamblin MR, Huan Raton: CRC Press; 2013. 10. Shanelec DA, Tib McGregor A, et al. Rec Newman MG, Takei HH Carranza’s Clinical Period 11. The photonics Publishing; 1997. 12. Myers TD. Lasers in 46-50. 13. Parker S. Surgical 2007;202(8):445-54. 14. McKenzie AL. Ph interaction. Phys Med Biol 15. Knappe V, Frank F, R effects. Photomed Laser Su 16. Bornstein E. Near- photo biologic princip 2004;23(3):102–104. 17. Miserendino LJ, Quintessence; 1995. p. 1 18. Simsek Kaya G, Y comparison of diode laser melanin pigmentation. Ora 2012, 113(3):293–299. 19. Ribeiro FV, Cavalle Dutra-Corrêa M, et al. Esth with Nd:YAG laser or scal professional assessment. La 20. Basha MI, Hegde R S. Comparison of Nd:YAG of Gingival Hyperpigment 2015;33(8):424-36. Treatment No. of Repigmentation studies rate (%) Bur abrasion 16 8.99 Scalpel 23 4.25 gingivoplasty Gingival graft 3 1.96 Laser 27 1.16 Electrosurgery 9 0.74 Cryosurgery 12 0.32 Laser Nd:YAG 4 2.86 CO2 4 2.14 Er:YAG 8 1.41 Diode 12 0.19 Table 2: Literature review 1951 – 2013; pigmentation recurrence rates (%) by random-effects Poisson regression1 HowardGluckmanBDS,MChD(OMP) Specialist inperiodonticsandoral medicine,directorof theImplant and AestheticAcademy Contact email: docg@theimplantclinic.co.za Telephone:+2721-426-2300 WebsiteURL: www.implantacademy.co.za JonathanDuToit BChD,Dipl.Implantol., DipOralSurg,MScDent Department of PeriodonticsandOralMedicine,School ofDentistry,FacultyofHealthSciences, UniversityofPretoria Dental Tribune Middle East & Africa Edition | 5/20169 Bur abrasion 168.99 Scalpel 234.25 Gingival graft 31.96 Laser 271.16 Electrosurgery 90.74 Cryosurgery 120.32 Nd:YAG 42.86 CO2 42.14 Er:YAG 81.41 Diode 120.19