title: Effect of biofilm formation, and biocorrosion on denture base fractures.
abstract: OBJECTIVE
  The aim of this study was to investigate the destructive effects of biofilm formation and/or biocorrosive activity of 6 different oral microorganisms.
  
  
  METHODS
  Three different heat polymerized acrylic resins (Ivocap Plus, Lucitone 550, QC 20) were used to prepare three different types of samples. Type "A" samples with "V" type notch was used to measure the fracture strength, "B" type to evaluate the surfaces with scanning electron microscopy and "C" type for quantitative biofilm assay. Development and calculation of biofilm covered surfaces on denture base materials were accomplished by SEM and quantitative biofilm assay. According to normality assumptions ANOVA or Kruskal-Wallis was selected for statistical analysis (α=0.05).
  
  
  RESULTS
  Significant differences were obtained among the adhesion potential of 6 different microorganisms and there were significant differences among their adhesion onto 3 different denture base materials. Compared to the control groups after contamination with the microorganisms, the three point bending test values of denture base materials decreased significantly (P<.05); microorganisms diffused at least 52% of the denture base surface. The highest median quantitative biofilm value within all the denture base materials was obtained with P. aeruginosa on Lucitone 550. The type of denture base material did not alter the diffusion potential of the microorganisms significantly (P>.05).
  
  
  CONCLUSIONS
  All the tested microorganisms had destructive effect over the structure and composition of the denture base materials.
authors.affiliation: School of Health Services, Dental Prosthetics Technology, Hacettepe University, Ankara, Turkey.
authors.forename: Cem
authors.initials: C
authors.lastname: Sahin
authors.forename: Alper
authors.initials: A
authors.lastname: Ergin
authors.forename: Simel
authors.initials: S
authors.lastname: Ayyildiz
authors.forename: Erdal
authors.initials: E
authors.lastname: Cosgun
authors.forename: Gulay
authors.initials: G
authors.lastname: Uzun
keywords: Biocorrosion; Biofilm; Denture base fractures; Microorganisms