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

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 gordonii, Porphyromonas gingivalis, and Fusobacterium nucleatum were grown in an anaerobic chamber at 37 degrees C. Samples were irradiated with the Nd:YAG laser (1064 nm, 300 mu m Varian tip) using parameters: 150 mJ, 20 Hz, 3 W, 50 sec, and 100 mu s 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.

Automated summary

The 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. Antiseptic solutions and laser were most effective against P. gingivalis, least effective against S. gordonii but improved significantly in combination with laser irradiation. Laser alone was effective against all three bacterial species, however, it was not significant.