An in vitro and in vivo study of plasma treatment effects on oral biofilms

Abstract

Management of dental plaque/biofilms is critical to maintain oral health. The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on oral biofilm formation and recovery under in vitro and in vivo conditions. Streptococcus mutans biofilms, a significant contributor to tooth decay, were cultured and treated by plasma. It was found that plasma treatment not only significantly reduced the in vitro biofilms, but also increased the metabolic activity of the bacteria in the biofilms. As compared with untreated control group, the cell metabolic activity, as measured by MTT assay, increased by 273%, and the aconitase activity increased by 446% for the plasma-treated group. The increased metabolic activity of the plasma-treated biofilm bacteria enhanced their susceptibility to antibiotic and host defense. An in vivo animal model using a total of 60 female rats (19 days old) were used to evaluate the anti-caries effects on the molars by 2 min of plasma treatment. It was found that, 6 months after the plasma treatment, the decayed surfaces were reduced by 62.5% on the upper molars and by 31.6% on the lower molars as compared with the untreated upper and lower molars, respectively. These in vitro and in vivo data demonstrate that the physiological state change of the biofilm due to plasma treatment provided benefit to caries control and prevention.

The Antimicrobial Effect of Cold Atmospheric Plasma against Dental Pathogens—A Systematic Review of In-Vitro Studies

“…In terms of a caries preventive therapy, Sprague-Dawley rats were treated with CAP for 2 min on the molars of one side, the other side served as control. After six months the caries rate on the test side was decreased by 20% compared to the control [ 29 ]. Another possible clinical application could be the disinfection of the cavity after caries excavation.…”

Biofouling Removal from Membranes Using Nonthermal Plasma

“…It is documented that the use of nonthermal plasma does not involve harmful chemical substances and it seems to be an interesting technique of cleaning the surface of membranes used in wastewater treatment. Moreover, the results demonstrated by Hong et al showed that plasma treatment not only inactivates the biofilm but also inhibits biofilm re-growth after surgery [67]. The authors re-cultured plasma-treated biofilms of Streptococcus mutans and observed interesting changes in the physiological activity of these bacteria.…”

Study of the impact of cultivation conditions and peg surface modification on the in vitro biofilm formation of Staphylococcus aureus and Staphylococcus epidermidis in a system analogous to the Calgary biofilm device

“…The differences can be observed, for example, in the cultivation time period, the initial density of bacterial suspensions, static versus shaking mode of cultivation, the substrate for initial bacterial attachment, and predominantly in the choice of cultivation media [18][19][20]. For staphylococcal biofilm formation, media such as Mueller-Hinton broth [21], brain heart infusion [22], minimal growth media and tryptic soy broth are often used [23,24]. For the enhancement of staphylococcal biofilm biomass formation in vitro, various media supplements (glucose, NaCl, HP, citrate, etc.)…”