title: Effect of two antimicrobial agents on early in situ biofilm formation.
abstract: OBJECTIVE
  The aim of this observer-blind, controlled, three-cell cross-over study was to evaluate the influence of an amine fluoride/stannous fluoride (Meridol, 250 ppm; ASF) and a chlorhexidine mouthrinse (CHX; Chlorhexamed forte, 0.2%) compared with water on in situ biofilm growth.
  
  
  METHODS
  After a professional toothcleaning seven volunteers had to wear a special acrylic appliance, in which six specimens each were inserted to allow the build-up of intra-oral biofilms. The volunteers had to rinse twice daily for 1 min. with 10 ml of the allocated mouthrinse. After 48 h of wearing, the specimens with the adhering biofilms were removed from the splints and stained with two fluorescent dyes, which selectively stain vital bacteria green and dead bacteria red. Under the confocal laser scanning microscope biofilm thickness (BT) was evaluated. To examine bacterial vitality (BV%) the biofilms were scanned (1 microm sections) and digital images were made. An image analysis program was used to calculate the mean BV as well as the BV of the single sections. After a wash-out period of 14 days a new test cycle was started.
  
  
  RESULTS
  The use of CHX and ASF resulted in a BT of 8.4+/-4.4 mum and 15.7+/-9.9 compared with 76.7+/-29.4 mum using water. The mean vitality (in %) was reduced from 66.1+/-20.4 to 23.3+/-11.6 and 23.9+/-12.4 using CHX and ASF, respectively. Both active solutions reduced BT and BV significantly compared with water (p<0.001). Differences between the two active solutions were not significant (p>0.05).
  
  
  CONCLUSIONS
  Both mouthrinses showed antibacterial and plaque-reducing properties against the in situ biofilm. The study design enables the examination of an undisturbed oral biofilm and for the first time shows the influence of antibacterial components applied under clinical conditions regarding biofilm formation.
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Hugstetter Strasse 55, 79106 Freiburg, Germany. auschill@zmk2.ukl.uni-freiburg.de
authors.forename: Thorsten M
authors.initials: TM
authors.lastname: Auschill
authors.forename: Nicole
authors.initials: N
authors.lastname: Hein
authors.forename: Elmar
authors.initials: E
authors.lastname: Hellwig
authors.forename: Marie
authors.initials: M
authors.lastname: Follo
authors.forename: Anton
authors.initials: A
authors.lastname: Sculean
authors.forename: Nicole B
authors.initials: NB
authors.lastname: Arweiler
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002710:Chlorhexidine / Q000627:therapeutic use*; D018592:Cross-Over Studies; D003773:Dental Plaque / Q000188:drug therapy / Q000382:microbiology*; D005460:Fluorides, Topical / Q000627:therapeutic use*; D006801:Humans; D009067:Mouthwashes / Q000627:therapeutic use*; D010516:Periodontal Splints; D016037:Single-Blind Method; D014002:Tin Fluorides / Q000627:therapeutic use*
chemical_list: D000891:Anti-Infective Agents, Local; D005460:Fluorides, Topical; D009067:Mouthwashes; D014002:Tin Fluorides; C094808:amine fluoride solution; D002710:Chlorhexidine