title: Anin vitroanalysis model for investigating the staining effect of various chlorhexidine-based mouthwashes.
abstract: BACKGROUND
  There are different mouthwashes containing chlorhexidine in different concentrations, as well as various excipients. Chlorhexidine induce stains or discoloration in teeth and mucous membranes. The aim of this work was to design a model to reproducein vitrostaining associated with the use of different mouthwashes containing chlorhexidine.
  
  
  METHODS
  We used as substrates of natural teeth and elephant ivory slices. Different incubation baths were conducted over 21 days in culture dishes at 37°C. At the beginning of experiment before incubation (D0) and after 21 days (D21) of incubation with different mouthwashes, pictures of substrates were taken in a standardized manner and an image analysis software was used to analyse and quantify the staining under the various conditions by using the 3 main colours (Red, Green, Blue, RGB).
  
  
  RESULTS
  The results of this work demonstrate a very good reproducibility of the protocol, and secondly, a different expression statistically significant of the primary blue colour. We suggest that for a given concentration of chlorhexidine, the staining effects may vary depending on the excipients used.
  
  
  CONCLUSIONS
  This replicable model, easy to implement over a relatively short duration, can be used for evaluation of existing mouthwashes, and to test the excipients anti discoloration proposed by manufacturers.Key words:In vitro, chlorhexidine, mouthwashes, dental stain, tooth discoloration.
authors.affiliation: DDS, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Alain-Ayepa
authors.initials: AA
authors.lastname: Kouadio
authors.affiliation: DDS, PhD, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Xavier
authors.initials: X
authors.lastname: Struillou
authors.affiliation: DDS, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Céline
authors.initials: C
authors.lastname: Bories
authors.affiliation: Prof, PhD, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Bouler
authors.affiliation: DDS, PhD, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Zahi
authors.initials: Z
authors.lastname: Badran
authors.affiliation: Prof, PhD, UFR d'odontologie. 1, Place A. Ricordeau, 44082, Nantes cedex2.
authors.forename: Assem
authors.initials: A
authors.lastname: Soueidan