Endodontic Photodynamic Therapy Ex Vivo

• Published in: Journal of endodontics Vol. 37; no. 2; pp. 217 - 222
• Main Authors: Ng, Raymond, Singh, Fiza, Papamanou, Despina A., Song, Xiaoqing, Patel, Chitrang, Holewa, Colleen, Patel, Niraj, Klepac-Ceraj, Vanja, Fontana, Carla R., Kent, Ralph, Pagonis, Tom C., Stashenko, Philip P., Soukos, Nikolaos S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2011
• Subjects: Bacteria - radiation effects; Chi-Square Distribution; Combined Modality Therapy; Debridement - methods; Dental Pulp Cavity - microbiology; Dental Pulp Cavity - radiation effects; Dental Pulp Cavity - surgery; Dental Pulp Necrosis - therapy; Dentistry; Disinfection - instrumentation; Disinfection - methods; Endocrinology & Metabolism; Endodontic disinfection; ex vivo; Humans; methylene blue; Methylene Blue - radiation effects; Methylene Blue - therapeutic use; Periapical Periodontitis - therapy; Photochemotherapy - instrumentation; Photochemotherapy - methods; photodynamic therapy; Radiation-Sensitizing Agents - radiation effects; Radiation-Sensitizing Agents - therapeutic use; Root Canal Therapy - instrumentation; Root Canal Therapy - methods; Treatment Outcome; methylene blue; Endodontic disinfection; ex vivo; photodynamic therapy
• ISSN: 0099-2399; 1878-3554; 1878-3554
• DOI: 10.1016/j.joen.2010.10.008

The objective of this study was to evaluate the antimicrobial effects of photodynamic therapy (PDT) on infected human teeth ex vivo. 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 26 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/cm 2. The contents of root canals were sampled by flushing the canals at baseline and after CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFUs). Partial characterization of root canal species at baseline and after CMD alone or CMD+PDT was performed by using DNA probes to a panel of 39 endodontic species in the checkerboard assay. The Mantel-Haenszel χ 2 test for treatment effects demonstrated the better performance of CMD+PDT over CMD ( P = .026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone ( P = .0003). After CMD+PDT, 45 of 52 canals (86.5%) had no CFUs as compared with 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 they were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17 of 22 (77.3%) and 15 of 29 (51.7%) canals in the CMD and CMD+PDT groups, respectively ( P = .034). 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.