Treatment with Nd:YAG Laser Irradiation Combined with Sodium Hypochlorite or Hydrogen Peroxide Irrigation on Periodontal Pathogens: An In Vitro Study

Grzech-Leśniak, K., Belvin, B. R., Lewis, J. P., & Golob Deeb, J.
An In Vitro Study, 39(1), 46–52.

Objective: 

The purpose of this study was to evaluate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with low concentrations of hydrogen peroxide (H2O2) or sodium hypochlorite (NaOCl) on viability of oral bacteria.

Materials and methods: 

Bacterial species Streptococcus gordoniiPorphyromonas gingivalis, and Fusobacterium nucleatum were grown in an anaerobic chamber at 37°C. Samples were irradiated with the Nd:YAG laser (1064 nm, 300 μm Varian tip) using parameters: 150 mJ, 20 Hz, 3 W, 50 sec, and 100 μs short pulse duration in contact mode. Treatment groups included (1) control, (2) Nd:YAG, (3) 0.5% H2O2, (4) Nd:YAG and 0.5% H2O2, (5) 0.5% NaOCl, and (6) Nd:YAG with 0.5% NaOCl. Viable colonies were counted, calculated into colony forming unit/mL, and converted into log form for statistical analysis using a two-tailed paired t-test.

Results:

The combined treatment with the Nd:YAG and H2O2 showed the greatest reduction in all bacterial viability compared with other treatment groups (p < 0.001). Antiseptic solutions and laser were most effective against P. gingivalis, least effective against S. gordonii but improved significantly in combination with laser irradiation (p < 0.001). Laser alone was effective against all of three bacterial species, however, it was not significant.

Conclusions: 

Combination treatment with Nd:YAG laser and an oxidative disinfectant (0.5% NaOCl or H2O2) resulted in more effective reduction of bacterial viability than monotherapies.

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