title: Biocorrosion of Endodontic Files through the Action of Two Species of Sulfate-reducing Bacteria: Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis.
abstract: This study assessed the biocorrosive capacity of two bacteria: Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis on endodontic files, as a preliminary step in the development of a biopharmaceutical, to facilitate the removal of endodontic file fragments from root canals.
  
  
  
  In the first stage, the corrosive potential of the artificial saliva medium (ASM), modified Postgate E medium (MPEM), 2.5 % sodium hypochlorite (NaOCl) solution and white medium (WM), without the inoculation of bacteria was assessed by immersion assays. In the second stage, test samples were inoculated with the two species of sulphur-reducing bacteria (SRB) on ASM and modified artificial saliva medium (MASM). In the third stage, test samples were inoculated with the same species on MPEM, ASM and MASM. All test samples were viewed under an infinite focus Alicona microscope.
  
  
  
  No test sample became corroded when immersed only in media, without bacteria. With the exception of one test sample between those inoculated with bacteria in ASM and MASM, there was no evidence of corrosion. Fifty percent of the test samples demonstrated a greater intensity of biocorrosion when compared with the initial assays.
  
  
  
  Desulfovibrio desulfuricans and D. fairfieldensis are capable of promoting biocorrosion of the steel constituent of endodontic files.
  
  
  
  This study describes the initial development of a biopharmaceutical to facilitate the removal of endodontic file fragments from root canals, which can be successfully implicated in endodontic therapy in order to avoiding parendodontic surgery or even tooth loss in such events.
authors.affiliation: Associate Professor, Medical School, Fluminense Federal University; School of Pharmacy, Federal University of Rio de Janeiro, Pharmaceutical Laboratory Bioassays; Laboratory of Biocorrosion and Biodegradation, National Institute of Technology, Rua Feliz da Cunha 11, ap. 806, Tijuca, CEP 20260300, Rio de Janeiro, Brazil, Phone: 55-21-9411-9341, e-mail: fabianohegg@gmail.com.
authors.forename: Fabiano Luiz
authors.initials: FL
authors.lastname: Heggendorn
authors.affiliation: Faculty of Dentistry, Estacio de Sa University, Rio de Janeiro Brazil.
authors.forename: Lucio Souza
authors.initials: LS
authors.lastname: Gonçalves
authors.affiliation: Medical School, Fluminense Federal University, Rio de Janeiro, Brazil.
authors.forename: Eliane Pedra
authors.initials: EP
authors.lastname: Dias
authors.affiliation: School of Pharmacy, Federal University of Rio de Janeiro Pharmaceutical Laboratory Bioassays, Rio de Janeiro, Brazil.
authors.forename: Viviane
authors.initials: V
authors.lastname: de Oliveira Freitas Lione
authors.affiliation: Laboratory of Biocorrosion and Biodegradation, National Institute of Technology, Rio de Janeiro, Brazil.
authors.forename: Márcia Teresa Soares
authors.initials: MT
authors.lastname: Lutterbach
mesh_terms: D003343:Corrosion; D003901:Desulfovibrio / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D004708:Endodontics / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000187:drug effects / Q000502:physiology*
keywords: Biocorrosion; Dental instruments; Desulfovibrio; Endodontic files; Microbiology; Sulfate-reducing bacteria