Aim: To evaluate the
in vitro antimicrobial effects of photodynamic therapy (PDT).
Methods: The
microorganism indicators were:
Candida albicans
,
Pseudomonas aeruginosa
,
Enterococcus faecalis
and
Staphylococcus aureus
. A microbial pool was prepared (10
8 cells/mL), from which
aliquots were transferred to culture plates for carrying out the PDT using methylene blue (50 μM)
and low-power laser (660 nm, 100 mW and 9 J).The effect of methylene blue alone, low power
laser and the absence of treatments were evaluated. Then, aliquots of 1 μL were plated in a media
culture, the number of colony forming units (CFU/mL) was obtained and the data submitted to the
F test (ANOVA) with Tamhane’s comparisons.
Results: The laser radiation in the presence of
methylene blue was able to eliminate 74.90% of
C. albicans, 72.41% of
P. aeruginosa, 96.44%
of
E. faecalis and 95.42% of
S. aureus, thus statistically significant differences were found among
the groups (
p<0.001).
Conclusions: PDT was effective in reducing the number of viable cells in
the studiedmicroorganisms, especially
E. faecalis and
S. aureus.
