The disinfectant effects of portable ultraviolet light devices and their application to dentures

Interest in ultraviolet (UV) light devices for disinfection has increased due to pandemic concerns, but their efficacy in denture disinfection is underexplored. This study evaluated seven-enclosed type portable UV irradiation devices (devices A–G). Among these, devices A, B, and C used bulb light sources, while devices D, E, F, and G utilized LED (light-emitting diode) light sources. All devices were assessed in agar plate assay, and Candida albicans and Staphylococcus aureus spread on agar plates and irradiated under two conditions: inoculated surface facing upward and downward. Colony counts were recorded. Devices A and D were tested on C. albicans-contaminated dentures immersed in C. albicans medium, with samples collected before and after irradiation on the mucosal surfaces of the dentures. Device A was tested on denture-wearing patients in a clinical study, with samples collected from mucosal surfaces before and after irradiation to assess microbial CFUs (colony forming units). Devices A, C, and D significantly reduced C. albicans and S. aureus on plates with the inoculated surface facing upward, while device F showed a slight reduction when the inoculated surfaces were facing downward. Devices A and D eliminated C. albicans on contaminated dentures in vitro. Device A reduced all microorganism CFUs on denture surfaces in clinical studies. This study demonstrates that some portable UV light devices effectively reduce microbial contamination on denture surfaces, suggesting their potential as valuable tools for improving denture hygiene in the future.