Endodontic Photodynamic Therapy Ex Vivo

Abstract

Objective To evaluate the anti-microbial effects of photodynamic therapy (PDT) on infected human teeth ex vivo. Materials and Methods Fifty-two freshly extracted teeth with pulpal necrosis and associated periradicular radiolucencies were obtained from 34 subjects. Twenty-six teeth with 49 canals received chemomechanical debridement (CMD) with 6% NaOCl and twenty-six teeth with 52 canals received CMD plus PDT. For PDT, root canal systems were incubated with methylene blue (MB) at concentration of 50 µg/ml for 5 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm2. The contents of root canals were sampled by flushing the canals at baseline and following CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFU). Partial characterization of root canal species at baseline and following CMD alone or CMD+PDT was performed using DNA probes to a panel of 39 endodontic species in the checkerboard assay. Results The Mantel-Haenszel chi-square test for treatment effects demonstrated the better performance of CMD+PDT over CMD (P=0.026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone (P=0.0003). Following CMD+PDT, 45 of 52 canals (86.5%) had no CFU as compared to 24 of 49 canals (49%) treated with CMD (canal flush samples). The CFU reductions were similar when teeth or canals were treated as independent entities. Post-treatment detection levels for all species were markedly lower for canals treated by CMD+PDT than were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17/22 (77.3%) and 15/29 (51.7%) of canals in the CMD and CMD+PDT group, respectively (P= 0.034). Conclusion Data indicate that PDT significantly reduces residual bacteria within the root canal system, and that PDT, if further enhanced by technical improvements, holds substantial promise as an adjunct to CMD.

Comparison of the Antibacterial Effect of 810 nm Diode Laser and Photodynamic Therapy in Reducing the Microbial Flora of Root Canal in Endodontic Retreatment in Patients With Periradicular Lesions

“…Moreover, the tissues underwent a relaxation time to modulate temperature changes. The results of this study on the effect of PDT is consistent with the those of many other studies such as Ng et al, 37 Garcez et al, 19,22,29,38,39 Bonsor et al, 27,28 Fonseca et al, 40 Foschi et al, 24 Fimple et al, 26 William et al, 21 and…”

Efficacy of antimicrobial photodynamic therapy for root canals infected with Enterococcus faecalis

“…In the studies assessed, 60 to 220 root canals were used; most studies used 60 to 125 teeth (25)(26)(27)(28)(29)(30)(31)(32)(33)(34), and only two studies used more than 125 teeth, Bacterial reductions in the experimental groups and positive control group were significantly greater than in the negative control (P < 0.001). However, only in group 2 (Er:YAG/NaOCl/NaCL/DW) did the bacterial reduction reach 100% on the surface of the root canal walls or 100/200 mm of the dentinal tubules.…”

“…(25,26,(28)(29)(30)(31)(32)(33)(34)(35)(36)(37), and one also used multi-rooted teeth (27). During sample preparation, root canals were sterilized and prepared before bacterial inoculation in all but three studies (26,27,33).…”

Effect of Different Irrigating Solutions and Photo-Activated Therapy for In Vivo Root Canal Treatment

“…In addition, most of the previous studies that showed adequate root canal disinfection with the use of PAD alone (12,25) or combined with chemomechanical debridement (25,26) sampled the root canal content using paper points or aspiration. These methods are limited by sampling only planktonic bacteria, not taking into account the bacteria organized in biofilms and inside dentinal tubules.…”