The Effect of High-Power Lasers on Root Canal Disinfection: A Systematic Review

Abstract

Introduction: In root canal therapy, the cleaning and shaping of canals are routinely applied by clinicians in order to remove microorganisms. Eradicating bacteria from the root canal system plays a crucial role in long-term success; however, it is not always easy to disinfect root canals properly because of their complicated anatomy and bacterial load. Achieving an optimally disinfected root canal environment requires adjunctive antibacterial therapeutic methods. High-power laser utilization as an adjunctive strategy to conventional treatment is a relatively new approach that helps clinicians. Methods: This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Online databases, namely Web of Science, PubMed/MEDLINE, Scopus, and Cochrane Library, were searched electronically regarding lasers and endodontic treatments. Appropriate studies were included according to the inclusion/exclusion criteria. Results: Among 504 obtained studies by search, 48 were considered for a detailed analysis. Ten articles performed in vivo evaluation, while nine assessed the effect of lasers on artificial models, and 29 conducted ex vivo experiments on extracted teeth. When the diode laser, the most frequently used laser, was utilized as an adjunct therapy after NaOCl irrigation, it killed more bacteria than conventional irrigation with NaOCl. Laser-activated irrigation (LAI) with the Er, Cr: YSGG laser and NaOCl disinfects the root canal effectively. Also, photon-induced photoacoustic streaming (PIPS) with Er: YAG and NaOCl exhibited a high bactericidal effect and deep tubular penetration. Conclusion: High-power laser utilization, considering proper case selection and method, can assist in root canal treatment of infected teeth.

Comparison of Antimicrobial Effects of 445 and 970 nm Diode Laser Irradiation with Photodynamic Therapy and Triple Antibiotic Paste on Enterococcus faecalis in the Root Canal: an In Vitro Study

“…Laser light radiation can eliminate non-pigment bacteria by increasing the temperature of water inside bacterial cells, while in pigmented bacteria, due to their high absorption in the pigmented components of bacteria, laser energy is selectively absorbed and released locally as heat, causing bacteria to be eliminated by increasing the temperature. Nowadays, lasers with different wavelengths, mainly diode lasers, are used for this purpose, and various results regarding bactericidal reduction have been reported (39)(40)(41)(42)(43). Recently, diode lasers with wavelengths in blue light range have also been introduced in dentistry.…”

Analyze the clinical effect of YAG laser combined with sodium hypochlorite in root canal treatment of pulpitis

“…At present, to improve the efficacy of irrigating agent, laser washing technology is gradually emerging in people's field of vision. Nd: YAG laser, as a solid‐state laser, can convert spectral energy into heat energy, remove most bacteria in root canal through thermal damage, and inhibit inflammatory reaction, which plays a good clinical role in the treatment of pulpitis 20,21 . Bergmans et al showed that the dentin disc with a thickness of 1 mm was inoculated with actinomyces and streptococcus in the same proportion, and after three times of irradiation with 1.5w Nd: YAG laser, it was found that the morphology of bacteria gradually changed with the increase of irradiation times, and finally the bacteria were completely destroyed 22 .…”

“…Nd: YAG laser, as a solid‐state laser, can convert spectral energy into heat energy, remove most bacteria in root canal through thermal damage, and inhibit inflammatory reaction, which plays a good clinical role in the treatment of pulpitis. 20 , 21 Bergmans et al showed that the dentin disc with a thickness of 1 mm was inoculated with actinomyces and streptococcus in the same proportion, and after three times of irradiation with 1.5w Nd: YAG laser, it was found that the morphology of bacteria gradually changed with the increase of irradiation times, and finally the bacteria were completely destroyed. 22 The pulp tissue and periodontal tissue are anatomically communicating with each other, and there are mixed infections dominated by anaerobic bacteria in both the periodontal pocket and the infected pulp.…”

Photobiomodulation Therapy and Pulp-Regenerative Endodontics: A Narrative Review

“…Decontamination of the root canal system is critical to the success of REPs and is accomplished through effective chemical-mechanical preparation, such as ultrasonically activated NaOCl [ 50 ]/EDTA [ 51 ] and the use of antibiotics in combination [ 52 ]. Aside from the ultrasonically activated NaOCl in endodontics, laser-assisted elimination of intra-canal microorganisms can be divided into two mechanisms: debris and smear-layer removal and disinfection of the root canal [ 53 ].…”

“…Maximum debris and smear-layer removal effects are achieved when laser light is used in root canals in conjunction with an appropriate concentration of a NaClO irrigating solution [ 53 ]. Many lasers, such as CO 2 [ 54 ], Nd:YAG [ 55 , 56 ], and erbium family (Er:YAG [ 57 ] and Er,Cr:YSGG [ 58 ]) ones have been reported to be used in removing debris and smear layers from infected canal walls.…”