title: Biofilm formation and release of fluoride from dental restorative materials in relation to their surface properties.
abstract: OBJECTIVE
  To elucidate the impact of surface properties and the release of fluoride from different glass ionomer cements on biofilm formation.
  
  
  METHODS
  Standardized specimens manufactured from various classes of glass ionomer cements (GICs), a resin-based composite (RBC), and human enamel were subjected to surface analyses. Subsequent to simulation of salivary pellicle formation, Streptococcus mutans biofilm formation was initiated using a drip flow reactor for 48h and 96h. Biofilms were characterized by determining viable bacterial biomass and 3D biofilm architecture using SEM and CLSM; the release of fluoride from the specimens was measured using the ion selective micro method in dependence on various experimental conditions (incubation with sterile broth/bacteria/acid).
  
  
  RESULTS
  Surface properties and biofilm formation correlated poorly, while the release of fluoride correlated well with viable streptococcal biomass and SEM/CLSM analyses. For all investigated materials, biofilm formation was lower than on enamel. The release of fluoride showed a significant dependency on the experimental conditions applied; the presence of biofilms reduced fluoride release in comparison to sterile incubation conditions.
  
  
  CONCLUSIONS
  Within the limitations of a laboratory study, the results suggest that biofilm formation on GICs cannot be easily predicted as a function of substratum surface parameters. The release of fluoride from glass ionomer cements contributes to control biofilm formation particularly in its early phases.
  
  
  CONCLUSIONS
  Glass ionomer cements can actively control microbial biofilm formation, while biofilms modulate the release of fluoride from GIC materials.
authors.affiliation: Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg, Germany. Electronic address: sebastian.hahnel@ukr.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hahnel
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, Italy.
authors.forename: Andrei C
authors.initials: AC
authors.lastname: Ionescu
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Cazzaniga
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ottobelli
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Brambilla
mesh_terms: D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D002327:Cariostatic Agents / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D003743:Dental Enamel / Q000382:microbiology; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle; D005459:Fluorides / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D013295:Streptococcus mutans / Q000187:drug effects / Q000502:physiology; D013499:Surface Properties; D013997:Time Factors
chemical_list: D002327:Cariostatic Agents; D003188:Composite Resins; D003764:Dental Materials; D005899:Glass Ionomer Cements; D005459:Fluorides
keywords: Biofilm; Fluoride; Glass ionomer cement; Resin composite