Bioabsorbable Cold Plasma‐Generated Nitric Oxide Gas and Plasma‐Activated Nitric Oxide Water: Inactivation of Oral Planktonic and Biofilm‐Forming Streptococcus mutans

Gas plasma exposure and plasma‐activated water (PAW) containing long‐lived reactive oxygen species (H ₂ O ₂ ) and nitrogen species (NO ₂ ^‒ , NO ₃ ^‒ ) generated by a multielectrode cylindrical dielectric barrier discharge plasma effectively inactivated oral bacteria Streptococcus mutans , opportunistic pathogen Staphylococcus aureus , and foodborne or intestinal Escherichia coli strains, which were used as comparator organisms. Gas plasma exposure to the water alters the water pH, H ₂ O ₂ , and NO _x (Combined NO ₂ ^‒ & NO ₃ ^‒ ) concentrations. Gas Plasma (NO _x and O ₃ ) achieved a 4–6 log reduction of bacteria within 16 min, while PAW induced a 5–6 log reduction within 3 days and reduced biofilm formation by 50 ± 0.21% ~ 40 ± 8.65%. These results show that bacteria, surface morphology, live/dead and RONS imaging, and flow cytometry consistently demonstrate that biocompatible plasma treatment significantly controls oral pathogens. Plasma gas and both distilled and tap‐water PAW effectively inhibited S. mutans , with higher selectivity than that of other bacteria. This study highlights the potential of PAW as a novel, biocompatible strategy to mitigate the virulence of oral bacteria.