Abstract: Objective: To clarify the application value of direct microscopy using fluorescence staining method in oral candidal infection. Methods: Two hundred and sixty-three patients suspected of oral candidiasis were included for fungal culture, fluorescence staining direct microscopy, and potassium hydroxide (KOH) microscopy examination. Results: The sensitivity, specificity, the positive predictive value, and the negative predictive value of direct microscopy using fungal fluorescence staining of 263 samples were 61.73%, 96.15%, 87.72%, and 84.95%, respectively. While the sensitivity, specificity, the positive predictive value, and the negative predictive value of KOH microscopy were 16.67%, 96.32%, 66.67%, and 72.35%, respectively. Using fungal fluorescence staining method to examine patients with oral lichen planus and oral candidiasis, the sensitivity was found to be 35.29% and 88.46%, respectively. The sensitivity of KOH method was only 5.88% and 35%, respectively. Conclusion: The fluorescence staining direct microscopy method had high sensitivity, simple operation, and rapid results, which could provide effective laboratory support for clinical diagnosis and treatment.

Key words: fluorescence staining method, fungal examination, oral candidiasis