Shedding light on lasers

Columns
LinkedIn

Lasers present contemporary uses in the field of endodontics, especially for refractory cases and mainly for smear layer removal and biofilm disinfection

keinan_headshot
Dr. David Keinan

The process of light amplification by stimulated emission of radiation (LASER) is a well-known phenomenon being used in various scientific fields. The energy is produced when excited atoms return to their base level and release photons. By using different laser mediums, the wavelength of the laser device is regulated and produces various energy levels. This energy was found to be applicable to various aspects in dentistry such as cavity preparation, bleeding control, soft tissue cutting, and disinfection. Therefore, it is not surprising that many studies have been conducted on laser technology for endodontic treatment (Green J, Weiss A, Stern A, 2011). Common lasers such as Er: YAG, Nd:YAG are used for cleaning, while CO2 lasers have been used for soft tissue surgery.

The main use of endodontic lasers includes smear layer removal and canal disinfection. Laser treatment was found efficient for reducing bacterial infection and can significantly enhance the long-term success of endodontic treatment (Siqueira JF Jr, 2001). Studies have demonstrated variable cleaning into dentinal tubules with Nd: YAG or diode lasers. The disinfection effectiveness of Er: YAG laser was found to be similar to sodium hypochlorite at various concentrations (Arnabat J, Escribano C, Fenosa A, et al., 2010; Folwaczny M, Mehl A, Jordan C, et al., 2002). This lethal effect of lasers can be increased by increasing the number of irradiation cycles (Moritz A, Schoop U, Goharkhay K, et al., 1999). Except for the photon effect on the bacteria, lasers can activate and increase the flow of the irrigants during root canal treatment. Laser active irrigation (LAI) was shown as an advanced technique to effectively remove debris from the canal walls (de Groot SD, Verhaagen B, Versluis M, et al., 2009; De Moor RJ, Blanken J, Meire M, et al., 2009; Sahar-Helft S, Slutzky-Goldberg I, Moshonov J, et al., 2011). This goal is achieved by forming large elliptical vapor bubbles that expand and then implode, therefore having a cavitation effect on the biofilm on the canal wall (de Groot SD, Verhaagen B, Versluis M, et al., 2009). In a similar way, the laser tip coronally positioned produces a forced streaming in a technique called photon-induced photoacoustic streaming (PIPS) (Pedullà E, Genovese C, Campagna E, et al., 2012).

The antimicrobial effect of a specific wavelength of lasers can be enhanced by using a photosensitizer on the treated area. This antimicrobial photodynamic therapy (aPDT) was considered for use against different oral pathogens, especially in the form of biofilm (Mang TS, Tayal DP, Baier R, 2012; Mang TS, Mikulski L, Hall RE, 2010). It was also noted that the weakened or changed biofilm matrix may be more easily removed or destroyed (Mang T, Rogers S, Keinan D, et al., 2016).

Laser treatment also has been also utilized to reduce dentinal hypersensitivity (Kimura Y, Wilder-Smith P, Yonaga K, et al., 2000; Senda A, Gomi A, Tani T, et al., 1985; Stabholz A, Neev J, Liaw LL, et al., 1993; Matsumoto K, Funai H, Wakabayashi H, et al., 1985). The mechanism of action may have two effects. The first involves physical blockage of the opened dentinal tubules by melting the dentin (Stabholz A, Neev J, Liaw LL, et al., 1993), and the second involves nerve analgesia by the energy of the laser (Matsumoto K, Funai H, Wakabayashi H, et al., 1985). The Er:YAG laser was found to have less pulpal damage from thermal changes during the irradiation (Belal MH, Yassin A, 2014).

In conclusion, lasers present contemporary uses in the field of endodontics, especially for refractory cases and mainly for smear layer removal and biofilm disinfection. The use of laser in endodontics is still limited mainly due to costs, but further studies are needed in order to explore their superiority over current methods of treatment.

Dr. David Keinan is a chief dental officer, medical corps for the Israel Defense Forces.

  1. Green J, Weiss A, Stern A. Lasers and radiofrequency devices in dentistry. Dent Clin North Am. 2011;55(3):585-597.
  2. Siqueira JF Jr. Strategies to treat infected root canals. Journal of the California Dental Association. 2001;29(12):825-837.
  3. Schoop U, Goharkhay K, Klimscha J, Zagler M, Wernisch J, Georgopoulos A, et al. The use of the erbium, chromium:yttrium-scandium-gallium-garnet laser in endodontic treatment: the results of an in vitro study. J Am Dent Assoc. 2007;138(7):949-955.
  4. Gordon J, Khan MH, Khatri KA. Erbium:YAG laser resurfacing using a novel portable device. Facial Plast Surg Clin North Am. 2007;15(2):185-189.
  5. Schoop U, Barylyak A, Goharkhay K, Beer F, Wernisch J, Georgopoulos A, et al. The impact of an erbium, chromium:yttrium-scandium-gallium-garnet laser with radial-firing tips on endodontic treatment. Lasers in Medical Science. 2009;24(1):59-65.
  6. Arnabat J, Escribano C, Fenosa A, Vinuesa T, Gay-Escoda C, Berini L, et al. Bactericidal activity of erbium, chromium:yttrium-scandium-gallium-garnet laser in root canals. Lasers in Medical Science. 2010;25(6):805-810.
  7. Yasuda Y, Kawamorita T, Yamaguchi H, Saito T. Bactericidal effect of Nd:YAG and Er:YAG lasers in experimentally infected curved root canals. Photomedicine and Laser Surgery. 2010;28(2)(suppl ):75-78.
  8. Folwaczny M, Mehl A, Jordan C, Hickel R. Antibacterial effects of pulsed Nd:YAG laser radiation at different energy settings in root canals. J Endod. 2002;28(1):24-29.
  9. Moritz A, Schoop U, Goharkhay K, Jakolitsch S, Kluger W, Wernisch J, et al. The bactericidal effect of Nd:YAG, Ho:YAG, and Er:YAG laser irradiation in the root canal: an in vitro comparison. J Clin Laser Med Surg. 1999;17(4):161-164.
  10. de Groot SD, Verhaagen B, Versluis M, Wu MK, Wesselink PR, van der Sluis LW. Laser-activated irrigation within root canals: cleaning efficacy and flow visualization. Int Endo J. 2009;42(12):1077-1083.
  11. De Moor RJ, Blanken J, Meire M, Verdaasdonk R. Laser induced explosive vapor and cavitation resulting in effective irrigation of the root canal. part 2: evaluation of the efficacy. Lasers Surg Med. 2009;41(7):520-523.
  12. Sahar-Helft S, Slutzky-Goldberg I, Moshonov J, Stabholtz A, Jacobovitz M, Tam A, et al. Synergistic effect of Er:YAG laser irradiation in combination with chlorhexidine on the viability of Enterococcus faecalis: an in vitro study. Photomedicine and laser surgery. 2011;29(11):753-758.
  13. Pedullà E, Genovese C, Campagna E, Tempera G, Rapisarda E. Decontamination efficacy of photon-initiated photoacoustic streaming (PIPS) of irrigants using low-energy laser settings: an ex vivo study. Int Endod J. 2012;45(9):865–870.
  14. Mang TS, Tayal DP, Baier R. Photodynamic therapy as an alternative treatment for disinfection of bacteria in oral biofilms. Lasers Surg Med. 2012;44(7):588-96. doi:10.1002/lsm.22050
  15. Mang TS, Mikulski L, Hall RE. Photodynamic inactivation of normal and antifungal resistant Candida species. Photodiagnosis and photodynamic therapy. 2010;7(2):98-105. doi:10.1016/j.pdpdt.2010.03.001
  16. Mang T, Rogers S, Keinan D, Honma K, Baier R. Antimicrobial photodynamic therapy (aPDT) induction of biofilm matrix architectural and bioadhesive modifications. Photodiagnosis Photodynamic Therapy. 2016;13:22-28.
  17. Kimura Y, Wilder-Smith P, Yonaga K, Matsumoto K. Treatment of dentine hypersensitivity by lasers: a review. J Clin Periodontol. 2000;27(10):715–721.
  18. Senda A, Gomi A, Tani T, et al. A clinical study on ‘‘Soft Laser 632,’’ a He-Ne low energy medical laser. Aichi-Gakuin J Dent Sciences. 1985;23(4):773–780.
  19. Stabholz A, Neev J, Liaw LH, Khayat A,Torabinejad M. Sealing of human dentinal tubules by XeCl 308-nm excimer laser. J Endod. 1993;19(6):267–271.
  20. Matsumoto K, Funai H,Wakabayashi H Oyama T. Study on the treatment of hypersensitive dentine by GaAlAs laser diode. Japanese J Conserv Dent. 1985;28:766–771.
  21. Belal MH, Yassin A. A comparative evaluation of CO2 and erbium-doped yttrium aluminium garnet laser therapy in the management of dentin hypersensitivity and assessment of mineral content. J Periodontal Implant Sci. 2014;44(5):227-234.

 

 

Stay Relevant With Endodontic Practice US

Join our email list for CE courses and webinars, articles and more..

Scroll to Top