Low-Pressure Radiofrequency Cold Plasma for Disinfection of Gutta-Percha Cones

Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants.

Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to one-minute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30-second or one-minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05).

S. aureus was completely eradicated in all groups. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Deconex® 53 PLUS (10%) was more potent than 2% CHX; however, the difference between 10% Deconex® 53 PLUS and other experimental groups was not significant (P>0.05).  

LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.