No abstract

Microwave irradiation for 3 min may be a potential treatment to prevent cross-contamination.

PDT appears to be an alternative treatment for DS.

The different methods of oral hygiene instruction used in this study indicate that the type of education was not of significant importance.

The prevalence of Candida spp. was similar between diabetic and nondiabetic patients with DS. Candida tropicalis may play a role in the progression of DS.

Objective: This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures. Background data: The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation. Methods: Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24 h. Dentures submitted to PDT (P + L + ) were individually sprayed with 50 mg/L of Photogem Ò (PS) and, after 30 min, illuminated by LED light for 26 min (37.5 J/cm 2 ). Additional dentures were treated only with PS (P + L-) or light (P-L + ) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48 h. The colonies were counted and the values of log (cfu/mL) were analyzed by KruskallWallis and Dunn tests ( p < 0.05). Results: For all species of Candida, PDT resulted in significant reduction ( p < 0.05) of cfu/mL values from dentures when compared with P-L-(reductions from 1.73 to 3.99 log 10 ). Significant differences ( p < 0.05), but lower reductions, were also observed for P + L-and P-L + when compared with P-L-for some species of Candida. Conclusions: PDT was an effective method for reducing Candida spp. on dentures.

The aim of this study was to evaluate the effectiveness of photodynamic therapy (PDT) for the disinfection of complete dentures. Biofilm samples were collected from dentures of 60 denture users who were randomly divided into four experimental groups (n = 15 each): subjects whose maxillary dentures were sprayed with 50 and 100 mg/l of Photogem® suspension (groups P50S and P100S) and patients whose maxillary dentures were treated with 50 and 100 mg/l of Photogem® gel (groups P50G and P100G). Dentures with photosensitizers were left in the dark for 30 min (pre-irradiation time) and then irradiated with blue LED light at 37.5 J/cm(2) (26 min). Denture samples were taken with sterile cotton swab before (left side surfaces) and after (right side surfaces) PDT. All microbial material was diluted and plated on selective media for Candida spp., Staphylococcus mutans spp., streptococci and a non-selective media. After incubation (48 h/37°C), the number of colony-forming units (cfu/ml) was counted. Microorganisms grown on selective media were identified using biochemical methods before and after PDT. The data were submitted to McNemar and Kruskal-Wallis tests (α = 0.05). No growth after PDT was observed in 60, 53, 47, and 40% of dentures from P100G, P50G, P100S, and P50S groups, respectively. When evidence of microorganisms' growth was observed, PDT regimens eliminated over 90% of microorganisms on dentures. This clinical study showed that PDT was effective for disinfecting dentures.

Microwave irradiation for 3 minutes at 650 W produced sterilization of complete dentures contaminated with S. aureus and P. aeruginosa. Dentures contaminated with B. subtilis were disinfected by microwave irradiation after 3 and 5 minutes at 650 W.