Inactivation of S. mutans dental biofilm by using Cold Atmospheric Plasma

Abstract S.mutans cells in oral cavity could adhere to surfaces of the teeth form the bacterial biofilm, strongly resist daily cleaning and brushing. The growth of the bacterial protected by the biofilm may lead to dental plaque formation and tooth decay. C old A tmospheric P lasma ( CAP ) generated from a capillary-guided corona discharge is investigated for the inactivation of Streptococcus mutans biofilm associated with dental caries. The plasma device was optimised to generate a 4-mm plasma plume while maintaining a temperature near to ambient. The heat generated was not susceptible to thermal damage for the biofilm, as well as the oral cavity. Through experimental evaluations, the gaseous plasma plume from the CAP with a treatment durations of up to 15 min were responsible in reducing the S. mutans biofilm. The highest removal was achieved after 15 min of CAP treatment. The results shown that a log-reduction of 3.08 of the cells in the S. mutans biofilm was killed during the treatment. The 10 min treatment demonstrated a high value of log reduction at 1.79 compared to the control well. The efficacy is found to be strongly correlated to treatment duration whereby at the minimum duration of 1 min treatment resulted a log reduction of 0.23. The outcomes of this research highlight CAP as a promising and safe approach for combating S. mutans biofilm. By offering a non-thermal alternative to traditional antimicrobial methods, CAP presents an opportunity to minimize harm to healthy tissues while effectively targeting biofilm.