title: Efficacy of citric acid denture cleanser on the Candida albicans biofilm formed on poly(methyl methacrylate): effects on residual biofilm and recolonization process.
abstract: BACKGROUND
  It is well known that the use of denture cleansers can reduce Candida albicans biofilm accumulation; however, the efficacy of citric acid denture cleansers is uncertain. In addition, the long-term efficacy of this denture cleanser is not well established, and their effect on residual biofilms is unknown. This in vitro study evaluated the efficacy of citric acid denture cleanser treatment on C. albicans biofilm recolonization on poly(methyl methacrylate) (PMMA) surface.
  
  
  METHODS
  C. albicans biofilms were developed for 72 h on PMMA resin specimens (n = 168), which were randomly assigned to 1 of 3 cleansing treatments (CTs) overnight (8 h). CTs included purified water as a control (CTC) and two experimental groups that used either a 1:5 dilution of citric acid denture cleanser (CT5) or a 1:8 dilution of citric acid denture cleanser (CT8). Residual biofilms adhering to the specimens were collected and quantified at two time points: immediately after CTs (ICT) and after cleaning and residual biofilm recolonization (RT). Residual biofilms were analyzed by quantifying the viable cells (CFU/mL), and biofilm architecture was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Denture cleanser treatments and evaluation periods were considered study factors. Data were analyzed using two-way ANOVA and Tukey's Honestly Significant Difference (HSD) test (α = 0.05).
  
  
  RESULTS
  Immediately after treatments, citric acid denture cleansing solutions (CT5 and CT8) reduced the number of viable cells as compared with the control (p < 0.01). However, after 48 h, both CT groups (CT5 and CT8) showed biofilm recolonization (p < 0.01). Residual biofilm recolonization was also detected by CLSM and SEM analysis, which revealed a higher biomass and average biofilm thickness for the CT8 group (p < 0.01).
  
  
  CONCLUSIONS
  Citric acid denture cleansers can reduce C. albicans biofilm accumulation and cell viability. However, this CT did not prevent biofilm recolonization.
authors: Department of Prosthodontics, School of Dentistry, Federal University of Pelotas, Pelotas, Rio Grande, do Sul 96015-560, Brazil. fernanda.faot@gmail.com.
authors: Fernanda
authors: F
authors: Faot
authors: Yuri Wanderley
authors: YW
authors: Cavalcanti
authors: Martinna de
authors: Md
authors: Mendonça e Bertolini
authors: Luciana de Rezende
authors: Lde R
authors: Pinto
authors: Wander José
authors: WJ
authors: da Silva
authors: Altair Antoninha Del Bel
authors: AA
authors: Cury
mesh_terms: D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D018533:Biomass; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development; D019343:Citric Acid / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle / Q000502:physiology; D003820:Denture Cleansers / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D050296:Microbial Viability; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003764:Dental Materials; D003820:Denture Cleansers; D014867:Water; D019343:Citric Acid; D019904:Polymethyl Methacrylate