title: Effect of fluoride and chlorhexidine digluconate mouthrinses on plaque biofilms.
abstract: To develop a model in which to investigate the architecture of plaque biofilms formed on enamel surfaces in vivo and to compare the effects of anti-microbial agents of relevance for caries on biofilm vitality. Materials and Methodology : Enamel discs mounted on healing abutments in the pre-molar region were worn by three subjects for 7 days. Control discs were removed before subjects rinsed with 0.1% chlorhexidine digluconate (CHX) or 0.2% sodium fluoride (NaF) for 1 minute. Biofilms were stained with Baclight Live/Dead and z-stacks of images created using confocal scanning laser micoscopy. The levels of vital and dead/damaged bacteria in the biofilms, assessed as the proportion of green and red pixels respectively, were analysed using ImageTrak(®) software. Results : The subjects showed individual differences in biofilm architecture. The thickness of the biofilms varied from 28-96µm although cell density was always the greatest in the middle layers. In control biofilms, the overall levels of vitality were high (71-98%) especially in the area closest to the enamel interface. Rinsing with either CHX or NaF caused a similar reduction in overall vitality. CHX exerted an effect throughout the biofilm, particularly on the surface of cell clusters whereas NaF caused cell damage/death mainly in the middle to lower biofilm layers. Conclusion : We describe a model that allows the formation of mature, undisturbed oral biofilms on human enamel surfaces in vivo and show that CHX and NaF have a similar effect on overall vitality but differ in their sites of action.
authors: Maxillofacial Unit, Halland Hospital, SE-301 85, Halmstad, Sweden.
authors: Per
authors: P
authors: Rabe
authors: Maxillofacial Unit, Halland Hospital, SE-301 85, Halmstad, Sweden ; Department of Odontology, Section of Cariology and Endodontics, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors: Svante
authors: S
authors: Twetman
authors: Department of Oral Biology, Faculty of Odontology, Malmö University, SE-206 05, Malmö, Sweden.
authors: Bertil
authors: B
authors: Kinnby
authors: Department of Oral Biology, Faculty of Odontology, Malmö University, SE-206 05, Malmö, Sweden.
authors: Gunnel
authors: G
authors: Svensäter
authors: Department of Oral Biology, Faculty of Odontology, Malmö University, SE-206 05, Malmö, Sweden.
authors: Julia R
authors: JR
authors: Davies
keywords: Anti-microbial agents; confocal microscopy; dental implants; dental plaque; enamel; vitality