Comparing Anti-bacterial Effect of CO2 Laser and 0.2% Chlorhexidine Solution on Staphylococcus aureus and Pseudomonas aeruginosa: In Vitro Study

Objectives: The bacterium causes different diseases in the oral cavity including angular cheilitis, bacterial sialadenitis in salivary glands, joint septic arthritis. In addition, the accumulation of bacteria on the surface of the implant develops the inflammation of mucous. The aim of this study was to compare the effects of CO2 laser with 2.0% chlorhexidine in a laboratory environment for eradicating Staphylococcus aureus and Pseudomonas aeruginosa. Materials and Methods: The effect of CO2 Laser was evaluated 5, 10, and 15 s after exposure to the standard suspension of bacterium at 24 and 48 h intervals and were cultured until the logarithmic phase and CO2 laser radiation with the wavelengths of 6 and 10 μm and energy density of 12.5 J/cm2 were radiated at a distance of 17 mm. Chlorhexidine 0.2% also was assessed at 5, 10, 15, and 60 s on the pathogens. Data were analyzed by descriptive statistics (mean ± standard deviation) and repeated measures ANOVA using SPSS 17. The P < 0.05 was considered statistically significant. Results: CO2 laser radiation was effective at all <15 s radiations on reducing both types of bacteria while the average numbers of S. aureus which were affected by 15 s of laser radiation and 60 s of chlorhexidine showed statistically significant difference (P = 0.014). The numbers of P. aeruginosa bacteria in the group which was exposed by laser for 15 s and the group which was treated by chlorhexidine were zero. Whereas, the average number of bacteria of laser treated group was lower than 0.2% chlorhexidine at both groups of bacteria. Laser radiation removed 100% of bacteria after 15 s in both groups of the bacteria. Conclusions: Findings of the present study indicate that laser irradiation for 15 s had equal results with chlorhexidine and more effective than 60 s treatment with chlorhexidine.