PURPOSE: To evaluate in vitro the antibacterial effect of diode laser light of wavelength 650 nm, in association with the photosensitive substance toluidine blue, on the bacteria in infected skin ulcers. METHODS: Samples were collected by means of swabs containing a medium for transporting infected material from skin ulcers. The material was inoculated into culturing medium containing azide blood agar for the growth of Gram-positive bacteria, and MacConkey agar for Gram-negative bacteria, and incubated for 48 hours. The results obtained from counting the colony-forming units were correlated and subjected to statistical analysis, adopting the significance level of p > or = 0.05. RESULTS: From analysis of variance (ANOVA), the result for the general mean was p = 0.0215. Using the t test with post-hoc test, the result for TBO vs. Control was p = 0.0186, and for TBO + Laser vs. Control it was p = 0.0039. CONCLUSION: There was a significant reduction in colony-forming units when the cultures were subjected to photodynamic therapy.
Photosensitizing Agents; Anti-Bacterial Agents; Skin Ulcers
