Toluidine blue-mediated photodynamic therapy of oral wound infections in rats.

The purpose of this study was to examine the effect of toluidine blue (TB)-mediated photodynamic therapy (PDT) on oral wound infections in rats. The study called for a combination treatment of a 1mg/ml solution of TB with a red light at three intensity settings of 12 J/cm(2), 24 J/cm(2) and 48 J/cm(2). In the group that was given the highest light dose of 48 J/cm(2), an average kill rate of approximately 97% was achieved. A lesser killing effect was achieved in the group that was subjected to the lowest light dose of 12 J/cm(2), where an average of approximately 25% of the bacteria survived. After PDT, the lesions were allowed to develop, and the peak size of the lesions was larger in the control group than in the test groups, especially for the 48 J/cm(2) group. We also observed that in the 24 J/cm(2) and 48 J/cm(2) groups the lesions were of significantly smaller size. Our study demonstrated that combined TB-PDT therapy can successfully treat oral wound infections in rats. These promising results recommend the use of this treatment as a possible alternative to topical anti-microbials in future clinical applications.