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Lethal photosensitization of bacteria in subgingival plaque from patients with chronic periodontitis
Author(s) -
Sarkar S.,
Wilson M.
Publication year - 1993
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.1600-0765.1993.tb01070.x
Subject(s) - fusobacterium nucleatum , microbiology and biotechnology , bacteria , porphyromonas gingivalis , periodontitis , fusobacterium , chronic periodontitis , bacteroides , anaerobic bacteria , chemistry , biology , medicine , dentistry , genetics
Subgingival plaque samples from patients with chronic periodontitis were exposed to light from a 7.3 mW Helium/Neon laser for 30 s in the presence and absence of 50 μg /ml toluidine blue O as a photosensitizer. Viable counts of various groups and species of bacteria were carried out before and after irradiation. The median numbers of viable bacteria initially present in the 30‐μl aliquots irradiated were 1.13 × 10 5 cfu (aerobes), 4.08 × 10 5 cfu (anaerobes), 4.92 × 10 3 cfu (black‐pigmented anaerobes), 4.75 × 10 2 cfu ( Porphyromonas gingivalis ), 6.15 × 10 3 cfu ( Fusobacterium nucleatum ) and 1.7 × 10 4 cfu (streptococci). The dye/laser combination achieved significant reductions in the viability of these organisms, the median reductions in the viable counts being 91.1% for aerobes, 96.6% for anaerobes, 100% for black‐pigmented anaerobes, P. gingivalis and F. nucleatum and 94.2% for streptococci. Overall, the viability of bacteria in the 20 plaque samples was not significantly decreased by the dye alone. However, in a small minority of samples there were indications of light‐independent, dye‐induced toxicity. Low‐power lasers, in conjunction with appropriate photosensitizers, may be a useful adjunct to mechanical debridement in the treatment of inflammatory periodontal diseases if a similar effectiveness against subgingival plaque bacteria can be achieved in vivo .