Bactericidal effects of a high‐power,red light‐emitting diode on two periodontopathic bacteria in antimicrobial photodynamic therapy in vitro |
| |
| Authors: | Makoto Umeda Akiko Tsuno Yoshihide Okagami Fumito Tsuchiya Yuichi Izumi Isao Ishikawa |
| |
| Affiliation: | 1. Department of Hard Tissue Engineering, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan;2. Division of Oral and Maxillo Facial Surgery, National Center for Global Health and Medicine, Tokyo, Japan;3. Department of Research and Development, J. Morita Manufacturing Corporation, Kyoto, Japan;4. Department of Pharmacy, Tokyo Medical and Dental University Hospital, Faculty of Dentistry, Tokyo, Japan;5. International Research Center for Molecular Science in Tooth and Bone Diseases, Tokyo Medical and Dental University, Tokyo, Japan;6. Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, Tokyo, Japan |
| |
| Abstract: | Aim: Light‐emitting diodes have been investigated as new light activators for photodynamic therapy. We investigated the bactericidal effects of high‐power, red light‐emitting diodes on two periodontopathic bacteria in vitro. Methods: A light‐emitting diode (intensity: 1100 mW/cm2, peak wavelength: 650 nm) was used to irradiate a bacterial solution for either 10 or 20 s. Bacterial solutions (Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans) at a concentration of 2.5 × 106 c.f.u./mL were mixed with an equal volume of either methylene blue or toluidine blue O (0–20 μg/mL) and added to titer plate wells. The plate wells were irradiated with red light‐emitting diode light from a distance of 22 or 40 mm. The contents were diluted, and 50 μL was smeared onto blood agar plates. After 1 week of culturing, bacterial c.f.u. were counted. Results: The light‐emitting diode energy density was estimated to be approximately 4 and 8 J/cm2 after 10 and 20 s of irradiation, respectively. Red light‐emitting diode irradiation for 10 s from a distance of 22 mm, combined with methylene blue at concentrations >10 μg/mL, completely killed Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Conclusion: High‐power, red light‐emitting diode irradiation with a low concentration of dye showed effective bactericidal effects against two periodontopathic bacteria. |
| |
| Keywords: | antimicrobial photodynamic therapy methylene blue periodontopathic bacteria red light‐emitting diode toluidine blue O |
|
|
