Efficacy of Atmospheric Pressure Plasma as an Antibacterial Agent Against Enterococcus Faecalis in Vitro

摘要

Enterococcus faecalis (E.faecalis)is a microorganism that can survive extreme challengesin obturated root canals.The aim of this study was to evaluate the efficacy of a non-thermalatmospheric pressure plasma plume against E.faecalis in vitro.A non-thermal atmospheric pressureplasma jet device which could generate a cold plasma plume carrying a peak current of300 mA was used.The antibacterial efficacy of this device against E.faecalis and its biofilm underdifferent conditions was detected.The antibacterial efficacy of the plasma against E.faecalisand Staphylococcus aureus (S.aureus)was also evaluated.After plasma treatment,the averagediameter of inhibition zone on S.aureus and E.faecalis was 2.62±0.26 cm and 1.06±0.30 cm,respectively (P < 0.05).The diameter was increased with prolongation of the treatment duration.The diameters of inhibition zone of the sealed Petri dishes were larger than those of theuncovered Petri dishes.There was significant difference in colony-forming units between plasmagroup and control group on E.faecalis biofilm (P < 0.01).The transmission electron microscopyrevealed that the ultrastructural changes cytoderm of E.faecalis were observed after treatmentfor 2 min.It is concluded that the non-thermal atmospheric pressure plasma could serve as aneffective adjunct to standard endodontic microbial treatment.