Evaluating The Efficiency Of Cold-Plasma Method Applied In Sterilization Of Microbe-Coated Materials

Abstract

Staphylococcus aureus can grow as structured biofilm on different surfaces, including oral mucosa and denture surfaces. Such biofilms can be released into the oral fluids and aspirated, causing systemic infections such as aspiration pneumonia. This study evaluated the efficacy of cold-plasma under time and voltage parameters in sterilization of dentures coated by S. aureus. Firstly, the microbial adhesion on denture surfaces was determined to select the best coating time for contamination of the dentures by S. aureus. The microbe-coated dentures were disinfected by the cold-plasma under time and voltage parameters, respectively. Non-treated dentures were used as positive controls. The viability of cells on dentures after treating with cold-plasma was evaluated by the standard plating method. After incubation (30oC for 24 hours), colonies were counted (CFUs/mL). The data was statistically analyzed by the one-way ANOVA test (α = 0.05). Cold-plasma treatment for 90 seconds at 110V, 1A, 5L/min Argon resulted in complete sterilization of dentures contaminated with S. aureus. The data showed that the sterilization efficiency of cold-plasma was strongly influenced by the time of treatment whereas the voltage effect was less important. Our findings also suggested that cold-plasma can be used as an excellent sterilization method for denture treatment. However, as cold plasma is a relatively costly method, more studies in gas composition of cold-plasma should be performed in order to generate the optimal conditions of cold-plasma for the most effective sterilization at the lesser cost. Key words: Cold-plasma, efficiency of sterilization, dentures, Staphylococcus aureus Keywords: Proteus mirabilis, Lactobacillus plantarum, cyclic dipeptides, antibacterial substance, antibacterial activities, supernatant.