Irradiation effects of low temperature multi gas plasma jet on oral bacteria

Abstract

The purpose of this study is to evaluate the sterilization effects of a newly developed low temperature multi gas plasma jet on oral pathogenic microorganisms (Streptococcus mutans [S. mutans], Lactobacillus fermentum [L. fermentum], Aggregatibacter actinomycetemcomitans [A. actinomycetemcomitans]). Plasma gas which generated from O2, N2, Ar and 50% (O2+N2) was irradiated to the microbes. Effect of O2 plasma irradiation on S. mutans under scanning electron microscopy (SEM) was also observed. O2 plasma was directly applied to dental plaque on human extracted tooth. Then, the depth of enamel resorption area was noted by nanoscale hybrid microscope. O2 had the best sterilizing effect for all microbes. The potent bactericidal effect of plasma irradiation was also observed by SEM. Decalcification of enamel was noted significantly lower in plasma irradiated tooth surface compared to no plasma exposure group. These findings revealed that multi gas plasma jet has great potential to be used for dental treatment.

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

“…Three studies investigated the effect of CAP on A. actinomycetemcomitans (Table 4). Direct application of argon plasma showed a non-significant reduction compared to the control group at a treatment time of less than 1 minute [19], but the numbers of CFU decreased to a non-detectable level after more than 10 minutes [56]. When using different working gases, the values of RF increased.…”

“…Rupf et al showed reduction values of 4.5 log10 and more using a mixture of helium, nitrous oxide and oxygen [33]. Treating for up to 60 s with nitrous oxide resulted in 0.6-1 log10 CFU reduction, pure oxygen rendered values from 1.3 log10 to complete sterilization and a combination of both gases showed no reduction up to 0.9 log10 CFU [19].…”

“…More than half of the studies used an argon plasma device. In the shortest treatment interval of up to 60 s, some groups demonstrated bacterial elimination below the detection level [21,28], whereas others found no significant reduction [19,20,22,25]. For the other time intervals, the RF ranged from no reduction [22] to 3.8 log10 CFU [26] within 120 s and from no reduction [22,25] to complete elimination of CFU [24] in 300 s, respectively.…”

“…For nitrogen plasma, studies with up to 60 and 120 s respectively were performed. In 60 s, values ranged between 0.6 [34] and 1.5 [19], 120 s resulted in 1 log10 CFU reduction [34]. Two groups of authors tested DBD plasma devices, utilizing ambient air.…”

“…Most authors focused on short treatment times of 60 s with devices that used argon as a working gas. In this category, one group of authors found no reduction [19], two others a decrease of CFU below detection level [21,33]. The other two studies demonstrated a consistent but relatively low reduction rate of about 1.0-1.5 log10 units.…”