title: Biofilm formation of Candida albicans on implant overdenture materials and its removal.
abstract: OBJECTIVE
  The purposes of this study were to clarify the surface characteristics of various implant overdenture materials and the capabilities of Candida albicans adherence and biofilm formation on these surfaces, and to investigate the role of salivary mucin in biofilm formation.
  
  
  METHODS
  Seven commonly used implant and restorative materials were assessed. The surface roughness averages of all materials were limited to 0.07-0.10 μm. Contact angles and salivary mucin absorption were measured. After 90-min initial adhesion and 2-day biofilm formation, the amounts of C. albicans were determined by counting colony-forming units and the morphological characteristics were observed by scanning electron microscopy (SEM). The effects of saliva coating and the influences of material surface property on initial adhesion, biofilm formation and its removability were analysed by univariate two-way analysis of variance and multiple linear regression analysis.
  
  
  RESULTS
  Surface contact angle of materials, the index of hydrophobicity, was found to be correlated positively with initial adhesion and biofilm formation of C. albicans. A negative correlation between mucin absorption and removability of Candida biofilm indicates that mucin plays an important role in biofilm formation and its rigidity. SEM observation also revealed fewer Candida cells on saliva-coated Ti than on saliva-coated hydroxyapatite or acrylic resin.
  
  
  CONCLUSIONS
  The materials with different hydrophobic property and compositions display diverse manners of salivary mucin absorption, initial adhesion and biofilm formation. The hydrophobic materials encourage enhanced initial adhesion, subsequently resulting in the active biofilm formation. Mucin has decisive effects on Candida immobilization and biofilm development on the materials.
  
  
  CONCLUSIONS
  Surface hydrophilic property and composition of materials and salivary proteins, especially mucin, affect the process of Candida biofilm formation and influence the amount and rigidity of formed biofilm. The present data may be applied as a reference for selecting materials in implant overdenture treatment from a microbiological point of view.
authors.affiliation: Department of Oral and Maxillofacial Prosthodontics and Oral Implantology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504, Japan.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hirota
authors.forename: Takaharu
authors.initials: T
authors.lastname: Goto
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yumoto
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Miyake
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ichikawa
mesh_terms: D000042:Absorption; D000180:Acrylic Resins / Q000737:chemistry; D018441:Biofilms / Q000254:growth & development*; D002176:Candida albicans / Q000502:physiology*; D024042:Collagen Type I / Q000737:chemistry; D015169:Colony Count, Microbial; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle / Q000502:physiology; D019094:Dental Prosthesis, Implant-Supported / Q000382:microbiology*; D003828:Denture, Overlay / Q000382:microbiology*; D017886:Durapatite / Q000737:chemistry; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008827:Microbiological Phenomena; D008855:Microscopy, Electron, Scanning; D009077:Mucins / Q000502:physiology; D010165:Palladium / Q000737:chemistry; D011093:Polyethylene Terephthalates / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D012471:Salivary Proteins and Peptides / Q000502:physiology; D012834:Silver / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D017155:Wettability; D015040:Zirconium / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D024042:Collagen Type I; D003764:Dental Materials; D006047:Gold Alloys; D009077:Mucins; D011093:Polyethylene Terephthalates; D011137:Polystyrenes; D012471:Salivary Proteins and Peptides; D012834:Silver; D010165:Palladium; D017886:Durapatite; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide