Effects of amine fluoride on biofilm growth and salivary pellicles.
The amine fluoride (AmF) N'-octadecyl-trimethylene-diamine-N,N,N'-tris(2-ethanol)-dihydro-fluoride is a cationic antimicrobial which can have beneficial effects on plaque formation. Here, we determine changes in pellicle and bacterial cell surface properties of the strains Actinomyces naeslundii HM1, Streptococcus mutans NS, S.mutans ATCC 700610, S. sobrinus HG1025 and S. oralis HM1 upon adsorption of this AmF and accompanying effects on bacterial adhesion and biofilm growth. In vitro pellicles had a zeta potential of -12 mV that became less negative upon adsorption of AmF. The chemical functionalities in which carbon and oxygen were involved changed after AmF adsorption and AmF-treated pellicles had a greater surface roughness than untreated pellicles. Water contact angles in vitro decreased from 56 to 45 degrees upon AmF treatment, which corresponded with water contact angles (44 degrees ) measured intraorally on the front incisors of volunteers immediately after using an AmF-containing toothpaste. All bacterial strains were negatively charged and their isoelectric points (IEP) increased upon AmF adsorption. Minimal inhibitory concentrations were smallest for strains exhibiting the largest increase in IEP. Adhesion to salivary pellicles and biofilm growth of the mutans streptococcal strains were significantly reduced after AmF treatment, but not of A. naeslundii or S. oralis. However, regardless of the strain involved, biofilm viability decreased significantly after AmF treatment. The electrostatic interaction between cationic AmF and negatively charged bacterial cell surfaces is pivotal in establishing reduced biofilm formation by AmF through a combination of effects on initial adhesion and killing. The major effect of AmF treatment, however, was a reduction brought about in biofilm viability.
Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands. h.c.van.der.mei@med.umcg.nl
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HC
van der Mei
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Engels
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de Vries
H J
HJ
Busscher
D000190:Actinomyces / Q000187:drug effects; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002327:Cariostatic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D044622:Dental Pellicle / Q000187:drug effects*; D003773:Dental Plaque / Q000188:drug therapy; D003959:Diamines / Q000494:pharmacology / Q000627:therapeutic use; D004563:Electrochemistry; D005260:Female; D005459:Fluorides; D005460:Fluorides, Topical / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D007526:Isoelectric Point; D008297:Male; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D013295:Streptococcus mutans / Q000187:drug effects; D019533:Streptococcus oralis / Q000187:drug effects; D016986:Streptococcus sobrinus / Q000187:drug effects; D017155:Wettability / Q000187:drug effects
D002327:Cariostatic Agents; D003959:Diamines; D005460:Fluorides, Topical; C094808:amine fluoride solution; C495399:Olaflur; D005459:Fluorides