Abstract: Objective: To discuss the effect of photo-activated disinfection (PAD) on acute pseudomembranous stomatitis model, compare the influence of different incubation time on curative efficacy, and provide experimental basis for PAD treatment. Methods: Thirty-six 6-week-old male ICR mice were randomly divided into three groups, with 12 mice in each group. The area of lingual dorsal lesion in all mice was measured before treatment. The back of the tongue in the two treatment groups was firstly coated with 1 mg/mL toluidine blue solution, and then the treatment group 1 was incubated for 1 min and treatment group 2 was incubated for 2 min. Both groups were finally given 750 mW LED red light for 1min. The control group received no treatment. After 48 hours, the clinical manifestations of the mice were observed, the lesion area of the tongue back was measured, and histopathological examination was evaluated. Results: Before PAD treatment, there was no significant difference in the score of pseudomembrane disease on lingual dorsum among three groups (P>0.05). Forty-eight hours after treatment, the scores of pseudomembrane of tongue in the two treatment groups were lower than that in the control group (P<0.05), however, no difference between two treatment groups (P>0.05). HE staining showed epithelial tissue thickening and irregular epithelial nailing, together with neutrophil infiltration in the superficial epithelium and formation of microabscesses at individual locations in the control group. The epithelial structures in the two treatment groups were regular, without significant difference. PAS staining showed that a large number of hyphae were covered in the control group, and hyphal invasion was observed on the superficial surface of epithelium. The number of hyphae in the two treatment groups was significantly lower than that in the control group. Mycelial invasion into the keratinized layer was occasionally observed, but it did not penetrate into the epithelial layer. No significant difference was observed between two treatment groups. Conclusion: Photo-activation disinfection technique can significantly reduce the symptoms of pseudomembrane on the back of the tongue in the mouse model of acute pseudomembranous stomatitis. The treatment of acute pseudomembranous stomatitis with 1 mg/mL toluidine blue solution incubated for 1min and 750 mW LED red light irradiated for 1min can achieve obvious therapeutic effect. Prolonging the incubation time to 2 min did not improve the therapeutic effect when other parameters remained unchanged.

Key words: photo-activated disinfection, candida albicans, acute pseudomembranous stomatitis