Purpose: This study aimed to establish a method for evaluating whether wearing dentures causes erythematous candidiasis, and to judge the necessity of eliminating Candida from the dentures. Therefore, the usefulness of microscopic observation of swabbed specimens from dentures was examined.
Method: Twenty-three cases, who were diagnosed as erythematous candidiasis clinically and who wore dentures (EC group), were included in this study. An additional nine cases of denture wearers served as a control (CTL group), who did not present clinical evidence of symptoms of candidiasis. Culture and microscopic examination were carried out for the detection of Candida. Because all cases in the EC group had a tongue lesion, samples were collected from the surface of the dorsum of the tongue. Specimens were also obtained from the surface of the tongue in the CTL group, whose tongues did not show lesions. Samples were obtained from the surface of the denture foundation in both groups. Fungiflora Y stain was used for the detection of Candida using a fluorescence microscope.
Results: In the EC group, Candida was detected at a high percentage of positivity from both the tongue lesion (20/23 cases, 87.0%) and the dentures (21/23 cases, 91.3%) by culture examination. Similarly, microscopy demonstrated a high positive rate in the dentures (17/23 cases, 73.9%), as well as in the tongue lesion (19/23 example, 82.6%). In the CTL group, Candida was detected with a comparatively high positive rate by culture examination sampling from both the dorsum of the tongue and the dentures, 7/9 cases (77.8%) and 6/9 cases (66.7%), respectively. On the other hand, microscopic examination in the CTL group detected Candida in only 3/9 cases (33.3%) from the dorsum of the tongue, and in no cases from the dentures. Thus, it was found that Candida was detected microscopically with a high rate from the denture foundation in cases of erythematous candidiasis.
Conclusion: The results suggest that dentures on which a Candida bio-film has formed are a potential cause of erythematous candidiasis, and that microscopic examination using Fungiflora Y is useful for evaluating the risk factor.