Antibacterial Effects of a Flavored Super-oxidized Water on Oral Pathogens

Objectives: Antibacterial activities of a new generation electrolyzed water; flavored super-oxidized water (f-SOW) on common oral pathogens were investigated.
Methods: The f-SOW (contains 125 mg/l of total chlorine concentration mainly hypochlorous-acid and with pH of 6.8) was applied on two species of cariogenic bacteria; Streptococcus mutans MT 8148 (S. mutans) and Streptococcus sobrinus 6715 (S. sobrinus) for 20 sec. Phosphate buffered saline (PBS) used as control. The treated bacteria were cultured on Mitis Salivarius agar plates in an anaerobic conditions at 37ºC and colony forming units (CFU) were counted. A vitality test was performed using fluorescence microscopy (FM) after staining with a LIVE/DEAD BacLight^TM Bacterial Viability Kit. Furthermore, antibacterial activity of f-SOW was assessed on Streptococcus gordonii ATCC 10558 (S. gordonii), Staphylococcus aureus 209P and Staphylococcus aureus Cowan1 using a radial diffusion assay (RDA) pipetting 10 μl of f-SOW in each well, PBS used as control. All plates were cultured under anaerobic conditions at 37°C for 48 h in an anaerobic box.
Results: In all experiments, f-SOW showed marked antibacterial activities compared with PBS-treated samples. On CFU counts, f-SOW showed significant reduction of bacterial growth; no colony could be detected on both S. mutans and S. sobrinus culture plates, whereas PBS had more than 2.8x10⁸ CFU/ml. Almost all bacteria found dead on FM observation. In RDA, f-SOW displayed growth inhibition of S. gordonii producing an average of 4-mm diameter clear zones and similar effect on two strains of Staphylococcus aureus was also confirmed. In the same conditions, PBS treated samples didn’t produce any clear zones.
Conclusions: These results suggest that f-SOW has strong bactericidal effect on cariogenic bacteria, even with a short exposure of 20 sec can kill more than 99% of these bacteria. It is also has the potentials to restrict the growth of oral pathogenic bacteria.