Antimicrobial efficiency of photodynamic therapy with different irradiation durations

Abstract

Objective:This study aimed to evaluate the antimicrobial efficiency of PDT and the effect of different irradiation durations on the antimicrobial efficiency of PDT.Materials and Methods:Sixty freshly extracted human teeth with a single root were decoronated and distributed into five groups. The control group received no treatment. Group 1 was treated with a 5% sodium hypochlorite (NaOCl) solution. Groups 2, 3, and 4 were treated with methylene-blue photosensitizer and 660-nm diode laser irradiation for 1, 2, and 4 min, respectively. The root canals were instrumented and irrigated with NaOCl, ethylenediamine-tetraacetic acid, and a saline solution, followed by autoclaving. All the roots were inoculated with an Enterococcus faecalis suspension and brain heart infusion broth and stored for 21 days to allow biofilm formation. Microbiological data on microorganism load were collected before and after the disinfection procedures and analyzed with the Wilcoxon ranged test, the Kruskal-Wallis test, and the Dunn's test.Results:The microorganism load in the control group increased. The lowest reduction in the microorganism load was observed in the 1-min irradiation group (Group 2 = 99.8%), which was very close to the results of the other experimental groups (99.9%). There were no significant differences among the groups.Conclusions:PDT is as effective as conventional 5% NaOCl irrigation with regard to antimicrobial efficiency against Enterococcus faecalis.

Differences in photodynamic therapy exposure time and Staphylococcus aureus counts

“…9 Moreover, the photosensitivity agents used in this research varied, consisting of photosensitisers containing toluidine blue which were derived from Fotosan, a class of phenothiazines that can kill bacteria at low concentrations without causing toxicity in the surrounding tissue. 13 Another potential factor is the use of optical fiber. Fiber in photoactivation can produce a superior effect because it can help to reach difficult-to-access areas.…”

Combined effects of photodynamic therapy and irrigants in disinfection of root canals

“…Yildirim and others compared the eradicative effect of 5% NaOCl for 15 min with PDT for 1 min and found that they were similar. However they analysed planktonic microbes rather than biofilm . A similar result was reported by Xhevdet and others for 2.5% NaOCl irrigation for 5 s and PDT for 1 min against E. faecalis and C. albicans .…”

Can Antimicrobial Photodynamic Therapy (aPDT) Enhance the Endodontic Treatment?

“…Yildirim et al, in evaluation of the effects of different light exposure durations on E. faecalis reduction, concluded that irradiation for 1 minute is adequate to achieve the antimicrobial effect. 42 Moreover, they found that by increasing the irradiation dose the antimicrobial effect was slightly greater, although this difference was not significantly important. In addition, Nunes et al reported comparable insignificant antimicrobial efficiency for different irradiation time in groups using MB and a diode laser for aPDT.…”