Premium
Specific‐wavelength visible light irradiation inhibits bacterial growth of Porphyromonas gingivalis
Author(s) -
Fukui M.,
Yoshioka M.,
Satomura K.,
Nakanishi H.,
Nagayama M.
Publication year - 2008
Publication title -
journal of periodontal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.31
H-Index - 83
eISSN - 1600-0765
pISSN - 0022-3484
DOI - 10.1111/j.1600-0765.2007.01009.x
Subject(s) - porphyromonas gingivalis , irradiation , monochromatic color , bacterial growth , growth inhibition , wavelength , visible spectrum , chemistry , blue light , bacteria , materials science , optics , microbiology and biotechnology , biophysics , optoelectronics , biology , cell growth , biochemistry , physics , genetics , nuclear physics
Background and Objective: The effects of laser irradiation on Porphyromonas gingivalis have been reported, but the results are still controversial regarding the efficiency because of the differences of the light sources and irradiation conditions. The aim of this study was to determine the wavelength and irradiation conditions under which the most effective inhibitory effect on P. gingivalis growth was seen without any photosensitizers. Material and Methods: Using an Okazaki large spectrograph, monochromatic light spectra ranging from 400 to 700 nm were evaluated to determine which spectra effectively inhibited bacterial growth. Moreover, using a monochromatic 405‐nm irradiating device, the effects of various irradiating conditions on P. gingivalis growth were examined. Results: Growth of bacteria irradiated at 400 nm and 410 nm was significantly suppressed compared with a nonirradiated control, whereas wavelengths of 430 nm and longer produced no significant inhibition. A constant energy density of 15 J/cm 2 was found to be enough to show an inhibitory effect. Significant inhibition of bacterial growth was found after only 1 min at 50 mW/cm 2 irradiation. Conclusion: These results indicate that P. gingivalis growth is specifically suppressed by 405‐nm light irradiation, suggesting that visible blue light irradiation is a promising means for eradicating periodontopathogenic bacteria from periodontal lesions.