title: Interface of dentine to root canal sealers.
abstract: OBJECTIVE
  Root canal sealers can interact physically or chemically with dentine. The aim of this study was to characterize the dentine-root canal sealer interface of experimental sealers based on Portland cement using an epoxy-based vehicle in comparison to an epoxy resin sealer, AH Plus.
  
  
  METHODS
  Root canals were biomechanically prepared and filled with any one of the four experimental epoxy sealers containing Portland cement with micro- and nano-particles of either zirconium oxide or niobium oxide radiopacifers, or AH Plus. The dentine-sealer's interfaces were assessed by coronal penetration of fluorescent microspheres, the penetration of sealers labelled with Rhodamine B inside the dentine tubules (following obturation with gutta-percha and sealers using System B technique) assessed by confocal laser scanning microscopy, and the chemical characterization of dentine-sealers interface by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) line scans.
  
  
  RESULTS
  No penetration of fluorescent microspheres at the root-dentine to sealer interface was recorded for all test materials. Sealers presented greater ability to penetrate within the dentinal tubules at the coronal and mid-root thirds. The experimental sealers containing radiopacifier nano-particles exhibited a more homogeneous microstructure along the whole length of the canal. EDS-line scans results showed a migration of silicon and niobium into dentine. Peak overlap between zirconium and the phosphorous compromised the identification of the migration of the zirconium oxide into dentine.
  
  
  CONCLUSIONS
  All five sealers promoted coronal sealing. The experimental sealers exhibited promising characteristics and were comparable to AH Plus sealer. Elemental migration of the experimental sealers suggests material interaction with dentine which was not displayed by AH Plus.
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, SP, Brazil.
authors.forename: Raqueli
authors.initials: R
authors.lastname: Viapiana
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, SP, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Guerreiro-Tanomaru
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, São Paulo State University (UNESP), Araraquara, SP, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Tanomaru-Filho
authors.affiliation: Department of Restorative Dentistry, Faculty of Dental Surgery, University of Malta, Malta. Electronic address: josette.camilleri@um.edu.mt.
authors.forename: J
authors.initials: J
authors.lastname: Camilleri
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure*; D004853:Epoxy Resins / Q000737:chemistry; D005456:Fluorescent Dyes; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry; D009556:Niobium / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D010758:Phosphorus / Q000737:chemistry; D012235:Rhodamines; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012823:Silicate Cement / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry
chemical_list: D017610:Calcium Compounds; D003287:Contrast Media; D004853:Epoxy Resins; D005456:Fluorescent Dyes; D010087:Oxides; D012235:Rhodamines; D012387:Root Canal Filling Materials; D017640:Silicates; C534916:epoxy resin-based root canal sealer; D009556:Niobium; D012823:Silicate Cement; D010758:Phosphorus; C506393:tricalcium silicate; D006171:Gutta-Percha; D015040:Zirconium; C029773:rhodamine B; C073337:niobium pentoxide; C028541:zirconium oxide; D012825:Silicon
keywords: AH Plus; Characterization; Fluorescent microspheres; Portland cement; Rhodamine B; Root canal obturation; Root dentine to sealer interface