title: Oral biofilm and caries-infiltrant interactions on enamel.
abstract: OBJECTIVE
  This study aimed to analyze interactions between oral biofilms and a dental triethylene glycol dimethacrylate (TEGDMA)-based resin infiltration material on enamel.
  
  
  METHODS
  Demineralized enamel specimens (14 days, acidic buffer, pH 5.0) were either infiltrated with a commercial TEGDMA resin and subjected to a three-species biofilm (Streptococcus mutans UAB 159, Streptococcus oralis OMZ 607 and Actinomyces oris OMZ 745) (group 1), applied to the biofilm (group 2), or merely resin infiltrated (group 3). A control group received no treatment (4). Biofilm formation and metabolic activity of biofilms were measured for group (1) and (2) after 24h CFU and a resazurin assay. Resin biodegradation was measured for group (1) and (3) by high performance liquid chromatography (HPLC) coupled with mass spectrometry after 6 and 24h incubation. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) images were taken to study the biofilm and material's autofluorescence in groups (1-4) after 24h.
  
  
  RESULTS
  SEM and CLSM images showed reduced biofilm formation on resin-infiltrated specimens (group 1) compared to group 2, while no biofilm was detectable on groups 3 and 4. CFU data (log10 CFU per mL) of group 1 showed significantly reduced bacterial numbers (p<0.05) compared to group 2. However, HPLC analysis of TEGDMA leakage after 6h and 24h revealed no differences between group 1 and group 3.
  
  
  CONCLUSIONS
  The results of the current study indicate that freshly resin-infiltrated enamel surfaces show a biofilm reducing effect, while monomer leakage was not affected by bacterial presence.
  
  
  CONCLUSIONS
  Resin infiltrated enamel surfaces are constantly exposed to the oral microflora. Yet, it is not known how biofilms interact with enamel-penetrated resins and if and to which extent accessory alignments in oral hygiene are needed.
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Center of Dental Medicine, Plattenstrasse 11, 8032 Zurich, Switzerland. Electronic address: punenina.tawakoli@zzm.uzh.ch.
authors.forename: Pune N
authors.initials: PN
authors.lastname: Tawakoli
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Center of Dental Medicine, Plattenstrasse 11, 8032 Zurich, Switzerland. Electronic address: thomas.attin@zzm.uzh.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Center of Dental Medicine, Plattenstrasse 11, 8032 Zurich, Switzerland; Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland. Electronic address: dirk.mohn@chem.ethz.ch.
authors.forename: Dirk
authors.initials: D
authors.lastname: Mohn
mesh_terms: D000190:Actinomyces / Q000187:drug effects / Q000502:physiology; D000818:Animals; D058491:Bacterial Load / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003731:Dental Caries / Q000382:microbiology*; D003743:Dental Enamel / Q000000981:diagnostic imaging / Q000382:microbiology*; D013058:Mass Spectrometry / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology*; D011109:Polymethacrylic Acids / Q000737:chemistry / Q000494:pharmacology*; D012117:Resins, Synthetic / Q000737:chemistry*; D013295:Streptococcus mutans / Q000187:drug effects / Q000502:physiology; D019533:Streptococcus oralis / Q000187:drug effects / Q000502:physiology; D014070:Tooth / Q000382:microbiology; D017001:Tooth Demineralization
chemical_list: D011109:Polymethacrylic Acids; D012117:Resins, Synthetic; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols
keywords: Caries; Enamel; HPLC; Oral biofilm; Resin; TEGDMA