title: Effectiveness of photodynamic therapy for the inactivation of Candida spp. on dentures: in vitro study.
abstract: 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
  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(®) (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 Kruskall-Wallis 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.
authors.affiliation: Dentistry School, São Francisco University, Bragança Paulista, SP, Brazil.
authors.forename: Ewerton Garcia de Oliveira
authors.initials: EG
authors.lastname: Mima
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Pavarina
authors.forename: Daniela Garcia
authors.initials: DG
authors.lastname: Ribeiro
authors.forename: Livia Nordi
authors.initials: LN
authors.lastname: Dovigo
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Vergani
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
mesh_terms: D002175:Candida / Q000187:drug effects*; D015169:Colony Count, Microbial; D003824:Denture, Complete / Q000382:microbiology*; D004203:Disinfection / Q000379:methods*; D006415:Hematoporphyrins / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000494:pharmacology; D013282:Stomatitis, Denture / Q000188:drug therapy* / Q000382:microbiology*
chemical_list: D006415:Hematoporphyrins; D017319:Photosensitizing Agents