Sensitisation of cariogenic bacteria to killing by light from a helium-neon laser.
Suspensions of the cariogenic bacteria Streptococcus mutans, S. sobrinus, Lactobacillus casei and Actinomyces viscosus were exposed to light from a 7.3-mW helium-neon laser in the presence of toluidine blue O. A substantial killing rate (c. 10(6) cfu) of all four species was achieved with a dye concentration of 50 micrograms/ml and a light energy dose of 33.6 J/cm2. This was achieved in 60 s, an exposure time that is clinically acceptable. Exposure to laser light in the absence of the dye did not significantly affect the viability of any of the organisms. This approach may be useful in dentistry to sterilise a carious lesion prior to its repair.
Department of Microbiology, Institute of Dental Surgery, London.
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T
Burns
M
M
Wilson
G J
GJ
Pearson
D016924:Actinomyces viscosus / Q000187:drug effects / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D006371:Helium; D007780:Lacticaseibacillus casei / Q000187:drug effects / Q000528:radiation effects*; D007834:Lasers; D008027:Light; D009356:Neon; D017319:Photosensitizing Agents; D013291:Streptococcus / Q000187:drug effects / Q000528:radiation effects*; D014048:Tolonium Chloride / Q000494:pharmacology
D017319:Photosensitizing Agents; D014048:Tolonium Chloride; D006371:Helium; D009356:Neon