title: Dental composite components induce DNA-damage and altered nuclear morphology in gingiva fibroblasts.
abstract: OBJECTIVE
  Released dental composite components can damage human gingival fibroblasts (HGFs) and their DNA. The cytotoxicity, chromatin condensation and the induction of DNA double strand breaks (DSBs) by different compounds of dental composites was investigated using an improved γ-H2AX focus assay.
  
  
  METHODS
  HGFs were incubated with the monomers: bisphenol-A-ethoxylate-dimethacrylate (Bis-DMA), bisphenol-A-glycerolate-dimethacrylate (BisGMA), ethyltriethylen glycol methacrylate (ETEGMA), glycidyl methacrylate (GMA), 1,6-hexandiol-dimethycrylate (HDDMA), trimethylolpropane ethoxylate triacrylate (TMPTA), and acrylamide (ACR). DSBs were determined by enumerating γ-H2AX and 53BP1 foci colocalized at DSBs.
  
  
  RESULTS
  A concentration-dependent induction of DSBs was found in the order: GMA>BisGMA>ACR>Bis-DMA>HDDMA>TMPTA>ETEGMA. HGFs exposure to GMA (0.3mM) and to BisGMA (0.09mM) induced the highest rate of DSB foci, i.e. 12-fold and 8-fold, respectively, relative to control (0.33 DSB foci/cell). At the highest concentrations (EC50) prominent changes in the chromatin morphology of HGF cell nuclei, i.e. compaction of nuclear chromatin and reduction of the area covered by the ovoid fibroblast nuclei, were observed. Nuclear condensation was significantly induced by GMA (1.7-fold at 0.3mM) and BisGMA (1.6-fold at 0.09mM), which correlated with the highest numbers of induced DSB foci (GMA, BisGMA, 3.9 and 2.6 foci/cell, respectively).
  
  
  CONCLUSIONS
  The improved γ-H2AX/53BP1 focus assay revealed a concentration-dependent increase in DSBs for all tested substances. Furthermore, concentration-dependent changes in HGF cell nucleus morphology was noted, demonstrating genotoxic effects of the substances tested.
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany. Electronic address: Marianthi.Styllou@gmx.de.
authors.forename: Marianthi
authors.initials: M
authors.lastname: Styllou
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany.
authors.forename: Franz-Xaver
authors.initials: FX
authors.lastname: Reichl
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany.
authors.forename: Panorea
authors.initials: P
authors.lastname: Styllou
authors.affiliation: Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany.
authors.forename: Ebru
authors.initials: E
authors.lastname: Urcan
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Rothmund
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hickel
authors.affiliation: Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336 Munich, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Högg
authors.affiliation: Bundeswehr Institute of Radiobiology affiliated to the University of Ulm, Neuherbergstr. 11, 80937 Munich, Germany.
authors.forename: Harry
authors.initials: H
authors.lastname: Scherthan
mesh_terms: D001559:Benzhydryl Compounds / Q000633:toxicity; D003188:Composite Resins / Q000633:toxicity*; D004247:DNA; D004249:DNA Damage; D003764:Dental Materials; D005347:Fibroblasts; D005881:Gingiva / Q000166:cytology; D006657:Histones; D006801:Humans; D008689:Methacrylates / Q000633:toxicity; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D003188:Composite Resins; D004247:DNA; D003764:Dental Materials; D006657:Histones; D008689:Methacrylates; C002462:4,4'-isopropylidenediphenol dimethacrylate; D000098826:Bisphenol A Compounds
keywords: 53BP1; Chromatin; DNA damage; DNA double-strand breaks; Dental composites; Gingiva fibroblasts; Monomers; Nuclear morphology; γ-H2AX