title: Antimicrobial penetration in a dual-species oral biofilm after noncontact brushing: an in vitro study.
abstract: OBJECTIVE
  Oral biofilm is inevitably left behind, even after powered brushing. As a special feature, powered brushing removes biofilm in a noncontact mode. When the brushing distance becomes too large, biofilm is left behind. We hypothesize that biofilm left behind after brushing has different viscoelastic properties than before brushing, impacting antimicrobial penetration.
  
  
  METHODS
  In vitro grown dual-species biofilms were subjected to 20 % mechanical deformation before and after powered brushing at 4-mm brushing distance. Biofilm thickness and stress relaxation were measured for unbrushed and brushed biofilms. Stress relaxation was analyzed with a three-element Maxwell model. Antimicrobial penetration from five mouthrinses was microscopically evaluated for unbrushed and brushed biofilms.
  
  
  RESULTS
  Thicknesses of unbrushed and brushed biofilms were similar. Brushing decreased the prevalence of fast and increased the prevalence of slow relaxation elements, which was accompanied by deeper penetration of chlorhexidine and cetylpyridinium chloride. Penetration of antimicrobials from other mouthrinses was relatively low in unbrushed and brushed biofilms.
  
  
  CONCLUSIONS
  This confirmation of our hypothesis points to an additional advantage of powered toothbrushing in a noncontact mode, changing the viscoelastic properties of biofilm in a direction that increases antimicrobial penetration of chlorhexidine and cetylpyridinium.
  
  
  CONCLUSIONS
  The biofilm left behind after noncontact powered toothbrushing may have less recalcitrance toward penetration of chlorhexidine and cetylpyridinium chloride than prior to brushing.
authors.affiliation: Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
authors.forename: Y
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
authors.forename: B W
authors.initials: BW
authors.lastname: Peterson
authors.affiliation: Department of Orthodontics, University of Groningen and University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: Y
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands. h.c.van.der.mei@umcg.nl.
authors.forename: H C
authors.initials: HC
authors.lastname: van der Mei
authors.affiliation: Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
authors.forename: H J
authors.initials: HJ
authors.lastname: Busscher
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage*; D018441:Biofilms; D066298:In Vitro Techniques; D014099:Toothbrushing
chemical_list: D000890:Anti-Infective Agents
references.citation: J Clin Periodontol. 1998 Dec;25(12):988-93
references.pmid: 9869348
references.citation: Cochrane Database Syst Rev. 2011 Dec 07;(12):CD008829
references.pmid: 22161438
references.citation: Int J Dent. 2010;2010:651869
references.pmid: 20414341
references.citation: Clin Oral Investig. 2013 Apr;17(3):687-709
references.pmid: 23001187
references.citation: J Periodontol. 2003 Jul;74(7):1017-22
references.pmid: 12931764
references.citation: FEMS Immunol Med Microbiol. 1999 Jun;24(2):189-92
references.pmid: 10378419
references.citation: J Am Dent Assoc. 2006 Dec;137(12):1649-57
references.pmid: 17138709
references.citation: Biotechnol Bioeng. 2011 Dec;108(12):2968-77
references.pmid: 21732324
references.citation: Appl Environ Microbiol. 2003 Aug;69(8):4770-6
references.pmid: 12902270
references.citation: Clin Oral Investig. 2012 Oct;16(5):1499-506
references.pmid: 22139463
references.citation: Eur J Oral Sci. 2010 Apr;118(2):177-82
references.pmid: 20487007
references.citation: Am J Dent. 2005 Jul;18 Spec No:9A-14A
references.pmid: 16178130
references.citation: Colloids Surf B Biointerfaces. 2011 Sep 1;86(2):251-9
references.pmid: 21592744
references.citation: Caries Res. 2002 Mar-Apr;36(2):93-100
references.pmid: 12037365
references.citation: Clin Oral Investig. 2010 Aug;14(4):403-9
references.pmid: 19565279
references.citation: PLoS One. 2013 May 27;8(5):e63750
references.pmid: 23723995
references.citation: J Dent. 2007 Apr;35(4):350-4
references.pmid: 17196730
references.citation: Periodontol 2000. 2008;48:10-22
references.pmid: 18715352
references.citation: J Dent Res. 2001 May;80(5):1436-40
references.pmid: 11437215
references.citation: Caries Res. 2010;44(5):459-64
references.pmid: 20838045
references.citation: J Periodontol. 1988 Apr;59(4):266-9
references.pmid: 3164377
references.citation: Oral Microbiol Immunol. 1993 Oct;8(5):277-82
references.pmid: 7903443
references.citation: Am J Dent. 2003 Apr;16(2):79-83
references.pmid: 12797563
references.citation: J Dent Res. 2009 Sep;88(9):841-5
references.pmid: 19767582
references.citation: J Dent Res. 1989 Nov;68(11):1479-82
references.pmid: 2531176
references.citation: J Bacteriol. 2003 Jun;185(11):3400-9
references.pmid: 12754239
references.citation: Int J Dent Hyg. 2008 Nov;6(4):280-9
references.pmid: 19138179
references.citation: Cytometry A. 2007 Aug;71(8):592-8
references.pmid: 17421025
references.citation: Caries Res. 2009;43(1):64-9
references.pmid: 19204390
references.citation: J Dent Res. 2013 Jul;92(7):616-21
references.pmid: 23674263
references.citation: Cytometry A. 2004 Oct;61(2):189-95
references.pmid: 15382024
references.citation: J Clin Dent. 2012;23(1):17-21
references.pmid: 22435320
references.citation: J Dent Res. 2006 Apr;85(4):298-305
references.pmid: 16567548