title: Assessment of inhibitory effects of fluoride-coated tubes on biofilm formation by using the in vitro dental unit waterline biofilm model.
abstract: This study aimed to establish an in vitro model to simulate biofilms formed in dental unit waterlines (DUWLs) and to investigate the ability of polyvinylidene fluoride (PVDF)-coated tubes to inhibit biofilm formation using this model. The water and biofilm samples were obtained from DUWLs which had been clinically used for 2.5 years, and the predominant bacteria were identified. A conventional polyurethane tube was incubated for 24 to 96 h in the mixed flora of isolated bacteria, and the optimal incubation conditions to simulate a clinically formed biofilm were determined by observation with a scanning electron microscope. Biofilm formation on a PVDF-coated tube was observed using this in vitro model, and the adherence of different bacterial species to conventional and PVDF-coated tubes was assessed. Sphingomonas paucimobilis, Acinetobacter haemolytics, and Methylobacterium mesophilicum were predominantly isolated from contaminated DUWLs. Incubation of the polyurethane tube with the mixed flora containing these three species for 96 h resulted in the formation of a mature biofilm similar to the one clinically observed. The PVDF-coated tube was significantly less adhesive to all three bacterial species than the polyurethane tube (P < 0.05 by the Mann-Whitney U test), and the attachment of small amounts of rods was observed even after incubation with the mixed flora for 96 h. In conclusion, an in vitro biofilm model was obtained by using a mixed flora of bacteria isolated from DUWLs, and the PVDF-coated tube was found to be effective in preventing biofilm formation using this model.
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yabune
authors.forename: Satoshi
authors.initials: S
authors.lastname: Imazato
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Ebisu
mesh_terms: D000150:Acinetobacter / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development* / Q000648:ultrastructure; D001422:Bacterial Adhesion; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D003770:Dental Offices; D004864:Equipment and Supplies / Q000382:microbiology; D020580:Methylobacterium / Q000302:isolation & purification; D008855:Microscopy, Electron, Scanning; D011145:Polyvinyls / Q000494:pharmacology*; D020578:Sphingomonas / Q000302:isolation & purification; D014871:Water Microbiology; D005465:Fluorocarbon Polymers
chemical_list: D000900:Anti-Bacterial Agents; D011145:Polyvinyls; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers