title: Chemical and X-ray analyses of five brands of dental gutta-percha cone.
abstract: OBJECTIVE
  To determine the chemical composition of five commercially available nonstandardized gutta-percha points.
  
  
  METHODS
  The organic fraction (gutta-percha polymer and wax/resin) of nonstandardized gutta-percha points (Dentsply, Tanari, Konne, Obtura Spartan and Analytic Endodontics) was separated from the inorganic fraction (ZnO and BaSO4) by dissolution in chloroform. Gutta-percha polymer was precipitated with acetone. Zinc oxide was partially separated from barium sulphate by reaction with HCl. Energy-dispersive X-ray microanalysis and X-ray diffraction were employed to identify the chemical elements and compounds (barium sulphate and zinc oxide). The barium sulphate content was calculated by percentage of sulphur from elemental microanalysis. All analyses were repeated three times.
  
  
  RESULTS
  The means and standard deviations of the percentage by weight of gutta-percha in the points were: Dentsply (14.5 +/- 0.70%), Tanari (15.6 +/- 0.66%), Obtura (17.7 +/- 0.35%), Konne (18.9 +/- 0.32%) and Analytic (20.4 +/- 0.40%). The mean and SD of the zinc oxide content were: Dentsply (84.3 +/- 0.50%), Tanari (82.0 +/- 0.72%), Obtura (69.5 +/- 0.21%), Konne (78.0 +/- 0.05%) and Analytic (66.5 +/- 0.50%).
  
  
  CONCLUSIONS
  The method was appropriate to quantify gutta-percha and resin/wax components of gutta-percha points, but not barium sulphate and zinc oxide. An alternative procedure to determine barium sulphate and zinc oxide contents has been proposed based on elemental microanalysis of sulphur. Some brands of gutta-percha did not contain barium sulphate.
authors.affiliation: Department of Endodontics, University of Fortaleza, Fortaleza, Ceará, Brazil. gurgeleduardo@aol.com
authors.forename: E D
authors.initials: ED
authors.lastname: Gurgel-Filho
authors.forename: J P
authors.initials: JP
authors.lastname: Andrade Feitosa
authors.forename: F B
authors.initials: FB
authors.lastname: Teixeira
authors.forename: R C
authors.initials: RC
authors.lastname: Monteiro de Paula
authors.forename: J B
authors.initials: JB
authors.lastname: Araújo Silva
authors.forename: F J
authors.initials: FJ
authors.lastname: Souza-Filho
mesh_terms: D004577:Electron Probe Microanalysis; D006171:Gutta-Percha / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D006171:Gutta-Percha