Bacteriologic Evaluation of the Effect of Nd:YAG Laser Irradiation in Experimental Infected Root Canals

Abstract

The aim of this study was to evaluate the efficacy of the Pumped Diodium-Nd:YAG laser in sterilizing contaminated root canals. After hand instrumentation, 30 teeth were inoculated with Actinomyces naeslundii CH-12 and 30 teeth with Pseudomonas aeruginosa ATCC 27853 and incubated for 24 h. The teeth were divided into three subgroups: subgroup A received no treatment; subgroup B was irradiated with laser (5 Hz for 15 s or 10 Hz for 15 s); and subgroup C was irrigated with 5.25% NaOCl. The number of viable bacteria in each group was evaluated by using the surface-spread plate technique. The results indicated an average of 34.0% decrease in colony-forming units for A. naeslundii CH-12 and 15.7% for P. aeruginosa ATCC 27853 with the 5 Hz/15 s laser treatment, and for the 10 Hz laser frequency, a decrease of the 77.4% for A. naeslundii CH-12 and 85.8% for P. aeruginosa ATCC 27853. No bacteria were detected in the canals treated with 5.25% NaOCl. The results show an antibacterial effect of the Pumped Diodium Nd:YAG laser, depending on the radiation frequency. However, 5.25% NaOCl was more effective than either laser application.

The principles of techniques for cleaning root canals

“…In vitro studies have shown that both CO 2 and X:YAG lasers possess potent antimicrobial activity, however comparative studies in simulated infected root canals have shown that the effect is either equal to, 131 or weaker than the action of NaOCl irrigation. 132 In addition, complex root canal systems and canal curvatures may reduce the effectiveness of lasers. Photo activated disinfection (PAD) employs a photosensitizer-containing solution which is introduced into the root canal and attaches to the cell wall of bacteria.…”

Effects of Nd:YAG Laser Pulpotomy on Human Primary Molars

“…In addition, the application of laser energy can lead to a significant reduction in pathologic agents in the root canal (13)(14)(15). Gutknecht et al demonstrated that an average of 99.9% of the bacteria could be eliminated following application of a Nd:YAG laser (13).…”

Comparative Evaluation of Root Canal Dentin on Efficacy of Smear Layer Removal with Nd:YAG Laser and EDTA after Rotary Instrumentation – SEM Study

“…Taskin Gurbuz exposed root canals to different irrigating solutions like saline, 5% NaOCl, 2% CHX, H 2 O 2, and EDTA along with Nd:YAG laser and lower scores for root cleaning were obtained using EDTA + Nd:YAG, 26 pumped sodium Nd:YAG slowed antibacterial effect depending on radiation frequency, however 5.25 % NaOCl is more effective. 27 However, studies by Saeed Rahim et al showed that 1% NaOCl along with Nd:YAG was effective even in E. faecalis biofilms. 28 Hence, all the samples were treated with 1% NaOCl as an irrigant during endodontic instrumentation.…”