title: Biofilm formation on stainless steel and gold wires for bonded retainers in vitro and in vivo and their susceptibility to oral antimicrobials.
abstract: OBJECTIVE
  Bonded retainers are used in orthodontics to maintain treatment result. Retention wires are prone to biofilm formation and cause gingival recession, bleeding on probing and increased pocket depths near bonded retainers. In this study, we compare in vitro and in vivo biofilm formation on different wires used for bonded retainers and the susceptibility of in vitro biofilms to oral antimicrobials.
  
  
  METHODS
  Orthodontic wires were exposed to saliva, and in vitro biofilm formation was evaluated using plate counting and live/dead staining, together with effects of exposure to toothpaste slurry alone or followed by antimicrobial mouthrinse application. Wires were also placed intra-orally for 72 h in human volunteers and undisturbed biofilm formation was compared by plate counting and live/dead staining, as well as by denaturing gradient gel electrophoresis for compositional differences in biofilms.
  
  
  RESULTS
  Single-strand wires attracted only slightly less biofilm in vitro than multi-strand wires. Biofilms on stainless steel single-strand wires however, were much more susceptible to antimicrobials from toothpaste slurries and mouthrinses than on single-strand gold wires and biofilms on multi-strand wires. Also, in vivo significantly less biofilm was found on single-strand than on multi-strand wires. Microbial composition of biofilms was more dependent on the volunteer involved than on wire type.
  
  
  CONCLUSIONS
  Biofilms on single-strand stainless steel wires attract less biofilm in vitro and are more susceptible to antimicrobials than on multi-strand wires. Also in vivo, single-strand wires attract less biofilm than multi-strand ones.
  
  
  CONCLUSIONS
  Use of single-strand wires is preferred over multi-strand wires, not because they attract less biofilm, but because biofilms on single-strand wires are not protected against antimicrobials as in crevices and niches as on multi-strand wires.
authors.affiliation: Department of Orthodontics, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700, Groningen, The Netherlands.
authors.forename: Marije A
authors.initials: MA
authors.lastname: Jongsma
authors.forename: Floris D H
authors.initials: FD
authors.lastname: Pelser
authors.forename: Henny C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: Jelly
authors.initials: J
authors.lastname: Atema-Smit
authors.forename: Betsy
authors.initials: B
authors.lastname: van de Belt-Gritter
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Busscher
authors.forename: Yijin
authors.initials: Y
authors.lastname: Ren
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D003722:Dental Alloys; D019551:Dental Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D003773:Dental Plaque / Q000188:drug therapy / Q000382:microbiology; D004338:Drug Combinations; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006047:Gold Alloys; D006801:Humans; D008297:Male; D009067:Mouthwashes / Q000737:chemistry / Q000494:pharmacology; D018704:Orthodontic Retainers / Q000382:microbiology; D009969:Orthodontic Wires / Q000382:microbiology*; D012459:Salicylates / Q000494:pharmacology; D012463:Saliva / Q000382:microbiology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013193:Stainless Steel; D018709:Statistics, Nonparametric; D013729:Terpenes / Q000494:pharmacology; D014100:Toothpastes / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D003722:Dental Alloys; D019551:Dental Disinfectants; D004338:Drug Combinations; D006047:Gold Alloys; D009067:Mouthwashes; D012459:Salicylates; D013729:Terpenes; D014100:Toothpastes; D013193:Stainless Steel; D012967:Sodium Dodecyl Sulfate; C057473:Listerine; D012969:Sodium Fluoride