The Atmosphere Pressure Plasma Jet (APPJ), one of the Dielectric Barrier Discharges (DBD), can be a promising tool for the non-thermal bacteria sterilization due to high amount of radical generation. 
To evaluate antibacterial activity, the viability and morphology of Porphyromonas gingivalis (P. gingivalis) were investigated after expose to APPJ. P. gingivalis was inoculated in 96 well multiplate and exposed to APPJ for 10, 30, 60 and 180 seconds, and then the viability and morphology were measured. The bacteria was incubated on Ti disc and in chamber slides for 3 days to form biofilm and exposed to APPJ for 1, 3 and 5 minutes, and then adhesion aspect of the bacteria were investigated with SEM and CLSM. 
Treatment with APPJ reduced the quantity of P. gingivalis over times. 
In addition, in Transmission electron micrographs (TEM) images, the most cells showed that the cytoplasmic contents were completely leaked out after expose to APPJ for 5minutes, leaving two distinct  membranes. In SEM images, little bacteria was detected on Ti disc after treatment for 3 minutes with APPJ. In CLSM images, dead cells were increased over times and little dead cells were investigated after treatment for 5minutes. Treatment with APPJ killed the majority of P. gingivalis and removed the bacteria from the surface of Ti disc. APPJ may be an effective adjunct to remove periodontal pathogen.

EAO-2018