Tuba Öztürk

Efficacy of endodontic applications of ozone and low‐temperature atmospheric pressure plasma on root canals infected with Enterococcus faecalis

This study aimed to compare the antimicrobial efficacy of low‐temperature atmospheric pressure plasma (LTAPP) design and gaseous ozone delivery system with 2·5% NaOCl on Enterococcus faecalis in root canal walls and dentine tubules. The samples were divided into LTAPP (n = 12), ozone (n = 12), NaOCl (positive control, n = 12) and saline (negative control, n = 6) groups. Microbial samples were collected using paper points and dentin chips from root canals. Antimicrobial efficacy was assessed by counting the colony‐forming units of Ent. faecalis before and after each irrigation protocol. Data were analysed using Kruskal–Wallis, Wilcoxon signed‐rank, Friedman and Bonferroni t (Dunns test)‐tests (P = 0·05). The microbial sampling with paper points showed antibacterial efficacy of NaOCl, LTAPP, ozone and saline in descending order, respectively (P < 0·05). The microbial sampling with dentin chips demonstrated a superior efficacy of LTAPP compared with NaOCl in the middle third (P < 0·05), while both had similar effects in coronal and apical thirds (P > 0·05). NaOCl and LTAPP were better than ozone at the coronal and middle parts of the root canals (P < 0·05). These findings led us to suggest that LTAPP, which has no thermal and chemical effects, may be of great aid in endodontic treatment.

Antibacterial efficacy of nonthermal atmospheric pressure plasma against

In this work, killer effects of nonthermal atmospheric pressure plasma on Candida albicans known as resistant microorganisms in the obdurate root canals were investigated. We produced atmospheric pressure plasma jet with 99% helium flow and 1% oxygen flow. Sabouraud dextrose agar (SDA) plates were inoculated with 0.2 mL broth culture of Candida albicans ATCC 254625 at three different concentrations of 0.5, 1 and 2 McFarland. Petri dishes and the pencil was also fixed at 10 mm. Plasma application was performed for 30s, 60s, 3m and 5m on each plate. For quantitative evaluation, 1ml broth culture of Candida albicans at concentration of 0.5 McFarland was prepared in 6 sterile Eppendorf tubes. The discharge was applied for 30s, 60s, 3m, 5m and 10 min on each tube. 13×20 mm area of microbial killing was observed with longer plasma exposure time (up to 5 min). The non thermal plasma can efficiently kill C. albicans in all application times. It seems to be harmless according to current root canal disinfectants because of its low temperature. Optical emission spectrum and current-voltage characteristics were given.