Study On The Atmospheric DBD Plasma Needle In The Of Sterilization Streptococcus Mutans

Compared to vacuum plasma, the atmospheric DBD plasma sources have recently received more attention due to their advantages, such as having no need for expensive vacuum equipment, being low-cost, and easy to operate. Therefore, a plasmaneedle using a dielectric barrier discharge reactor at atmospheric pressure with a funnel-shaped nozzle was designed and realized.The preliminary characteristics of the plume and its application in the sterilization of Streptococcus mutans(S.mutans), which is the most important microorganism for causing dental caries, were presented in this paper. The reactor produced a cold plasma plume with temperature not higher than 315K at power 5-28W. The effect of oxygen, which was injected downstream in the plasma afterglow region through a steel tube, on the plasma jet was show in spectrum and find addition of 26ml/min O₂ led to the transport of atomic 0 further without significant effects on the jet length. To find key radicals which are responsible to kill S.mutans we compare the spectrum at atmosphere with the spectrum in agar.The preliminary characteristics of the plume and applications in ablation Human Hepatocarcinoma Cell Line (BEL-7402) were presented. The effect of oxygen, which was injected into argon plasma afterglow region through a steel tube, was studied. The efficiency of argon-oxygen plasma depends very sensitively on the oxygen concentration in argon plasma. Large differences between spectra in atmosphere and that in Dulbecco's Modified Eagle Medium were found. It is found that ultraviolet rays, 0 and Ar radicals can reach the bottom of solution and act on liver cancer cells and there is an Optimum input power to get the most radicals.