title: No evidence for DNA double-strand breaks caused by endodontic sealers.
abstract: BACKGROUND
  On extrusion, endodontic sealers might come into close contact with the periapical tissues for long periods. The objective of this study was to test possible mutagenicity of resin-based endodontic sealers by evaluating their potential to induce DNA double-strand breaks (DSBs).
  
  
  METHODS
  Human gingival fibroblasts were exposed to subtoxic concentrations of eluates from 1 epoxy resin-based endodontic sealer (AH Plus Jet) and 2 methacrylate-based endodontic sealers (EndoRez and Real Seal). As control, Calcicur, a Ca(OH)(2)-based sealer, was used. The γ-H2AX immunofluorescence assay was used to microscopically detect DNA DSBs, and a custom algorithm was developed to quantify them.
  
  
  RESULTS
  The cytotoxicity of the 24-hour eluates could be ranked in the following order: AH Plus Jet > Real Seal > EndoRez >> Calcicur. The γ-H2AX assay revealed that 1.3%-4.3% of the cell nucleus was occupied by foci when the cells were exposed to the eluates of the endodontic sealers. This was not significantly different from the negative control group in which the cells had been exposed to medium (2.1%).
  
  
  CONCLUSIONS
  No indications for increased risk of genotoxicity of resin-based root canal sealers caused by the induction of DNA DSBs were found in this study.
authors.affiliation: Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilian University of Munich, Munich, Germany. kirsten.vanlanduyt@med.kuleuven.be
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Van Landuyt
authors.forename: Benjamin
authors.initials: B
authors.lastname: Geebelen
authors.forename: Mostafa
authors.initials: M
authors.lastname: Shehata
authors.forename: Silja L
authors.initials: SL
authors.lastname: Furche
authors.forename: Jürgen
authors.initials: J
authors.lastname: Durner
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
authors.forename: Reinhard
authors.initials: R
authors.lastname: Hickel
authors.forename: Franz X
authors.initials: FX
authors.lastname: Reichl
mesh_terms: D002126:Calcium Hydroxide / Q000494:pharmacology; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003188:Composite Resins / Q000633:toxicity; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects*; D004853:Epoxy Resins / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006657:Histones / Q000032:analysis; D006801:Humans; D007202:Indicators and Reagents; D008422:Materials Testing; D009153:Mutagens / Q000633:toxicity; D019279:Resin Cements / Q000633:toxicity; D012387:Root Canal Filling Materials / Q000633:toxicity*; D013696:Temperature; D013778:Tetrazolium Salts; D013997:Time Factors
chemical_list: C559663:Calcicur; D003188:Composite Resins; C481259:EndoRez; D004853:Epoxy Resins; C468783:H2AX protein, human; D006657:Histones; D007202:Indicators and Reagents; D009153:Mutagens; C511498:Real Seal composite resin; D019279:Resin Cements; D012387:Root Canal Filling Materials; D013778:Tetrazolium Salts; C534916:epoxy resin-based root canal sealer; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide; D002126:Calcium Hydroxide