title: Chemical elements characterization of root canal sealers using scanning electron microscopy and energy dispersive X-ray analysis.
abstract: BACKGROUND
  The aim of this study was to evaluate the chemical elements composition of root canal filling materials using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX).
  
  
  METHODS
  Eighteen standard polyethylene tubes were filled with the following materials: Sealapex(®), Sealer 26(®), MTA Fillapex(®), Pulp Canal Sealer(®), Endofill(®) and AH Plus(®). After 48 hours at 37°C and 95% relative humidity, the samples were surface-sputtered with gold and analyzed using SEM at 5000X magnification. Their chemical composition and element distributionwere determined using EDX. Results were evaluated qualitatively (SEM images and elemental mapping) and quantitatively (weight percentage).
  
  
  RESULTS
  Calcium oxide- and hydroxide-based sealers (Sealapex(®) and Sealer 26(®)) had calcium peaks of 53.58 wt% and 65.00 wt%. MTA Fillapex(®) had 30.58 wt% of calcium and high amounts of silicon (31.02 wt%) and bismuth (27.38 wt%). Zinc oxide- and eugenol-based sealers, Pulp Canal Sealer(®) and Endofill(®), had 67.74 wt% and 63.16 wt% of zinc each. AH Plus(®) had a higher amount of zirconium (64.24 wt%). All materials had elements other than those described by the manufacturers. Surface analysis using EDX revealed that regularity varied, element distribution was uniform, and particles had similar sizes and variable shapes.
  
  
  CONCLUSIONS
  Most chemical elements were those described by the manufacturers, but percentages were different. The surface of root canal sealers had different regularity findings, uniform distribution and particles of similar sizes but variable shapes.
authors.forename: Felipe Cavalcanti
authors.initials: FC
authors.lastname: Sampaio
authors.forename: Ana Helena Gonçalves
authors.initials: AH
authors.lastname: Alencar
authors.forename: Orlando Aguirre
authors.initials: OA
authors.lastname: Guedes
authors.forename: Heloisa Helena Pinho
authors.initials: HH
authors.lastname: Veloso
authors.forename: Tatiane Oliveira
authors.initials: TO
authors.lastname: Santos
authors.affiliation: Department of Stomatologic Sciences, Federal University of Goiás, University Square s/n, University Sector, CEP 74605-220, Goiânia, GO, Brazil, Tel: +(62) 39457476 ; e-mail: estrela3@terra.com.
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela