title: Influence of acrylic resin polymerization methods and saliva on the adherence of four Candida species.
abstract: BACKGROUND
  There is limited information on the role of polymerization methods and saliva on the adherence of pathogenic Candida species, with the exception of the adherence of Candida albicans to acrylic resins and the relation of this to surface roughness and surface free energy, which appear to play a major role in the initial phases of microorganism adhesion.
  
  
  OBJECTIVE
  This study evaluated the influence of polymerization methods and human whole saliva on the adherence of Candida species to acrylic resin surfaces.
  
  
  METHODS
  Acrylic resin specimens (n=256) measuring 2.5 x 1.2 x 0.2 cm were heat (Classico) or microwave (OndaCryl) polymerized and evaluated for surface roughness using a profilometer, and for surface free energy by measuring the contact angle of a sessile drop of water. For the adherence assay, specimens of each acrylic resin were divided by lottery into 8 groups, according to whether they were exposed to human saliva or not (control), and to 1 of the 4 following suspensions: C albicans, Candida tropicalis, Candida dubliniensis, or Candida glabrata (1 to 5 x 10(6) cells/mL). Adhered yeasts were counted using an optical microscope at x400 magnification. Data were analyzed by 3-way ANOVA and the Tukey honestly significant difference test (alpha=.05).
  
  
  RESULTS
  No statistical difference was found for roughness (P=.156), whereas higher surface free-energy values were found for the heat-polymerized acrylic resin (P=.0013). The overall adherence of Candida species was significantly decreased by human saliva (P<.001).
  
  
  CONCLUSIONS
  Within the limitations of this study, saliva was capable of reducing the adherence of Candida species, whereas roughness and free energy did not influence the adherence rates.
  
  
  CONCLUSIONS
  As growth on surfaces is a natural part of the Candida lifestyle, its colonization in denture users may be expected. The presence of human whole saliva, however, decreased the overall yeast adherence to the acrylic resin surface, whereas surface roughness and free energy did not interfere with the adherence of Candida species.
authors.affiliation: School of Dentistry of Piracicaba, State University of Campinas, Sao Paulo, Brazil
authors.forename: Juliana Silva
authors.initials: JS
authors.lastname: Moura
authors.forename: Wander Jose
authors.initials: WJ
authors.lastname: da Silva
authors.forename: Tatiana
authors.initials: T
authors.lastname: Pereira
authors.forename: Altair A
authors.initials: AA
authors.lastname: Del Bel Cury
authors.forename: Renata Cunha Matheus
authors.initials: RC
authors.lastname: Rodrigues Garcia
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D001422:Bacterial Adhesion; D002175:Candida / Q000502:physiology*; D003819:Denture Bases / Q000382:microbiology*; D006358:Hot Temperature; D006801:Humans; D008872:Microwaves; D044367:Phase Transition; D012463:Saliva / Q000502:physiology*; D013045:Species Specificity; D018709:Statistics, Nonparametric; D013499:Surface Properties; D017155:Wettability
chemical_list: D000180:Acrylic Resins