title: Presence of pores and vacuoles in set endodontic sealers.
abstract: OBJECTIVE
  To assess qualitatively the presence of pores and vacuoles in the structure of various endodontic sealers when set.
  
  
  METHODS
  Eight specimens were prepared in keeping with Instituto Argentino de Racionalización de Materiales (IRAM) and ISO regulations for each of the 10 sealers assessed. Four specimens per sealer were examined to identify the presence of structural defects, termed pores, on the external surface. The remaining four specimens were used to examine the presence of defects on the surface exposed by cross-sectional fracture; these were termed vacuoles. The largest and smallest diameters of the pores and vacuoles were measured by scanning electron microscope on both surfaces. The structural defects were classified according to their frequency as abundant, frequent, scarce or exceptional.
  
  
  RESULTS
  Pores and vacuoles were consistently found in every specimen of each sealer. However, their frequency and dimensions were greater in zinc-eugenol-based sealers than in epoxy-resins and glass-ionomer sealers; they increased if the sealer contained calcium hydroxide. The diameter of the pores ranged from 5 to 320 microm and the diameter of the vacuoles ranged from 80 to 500 microm. The diameter of the vacuoles always exceeded that of the pores.
  
  
  CONCLUSIONS
  Pores and vacuoles were a consistent finding in set sealers. Their frequency and size depended on the density of the sealer and increased when the sealers contained calcium hydroxide.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, National University of Córdoba, Córdoba, Argentina. lilimutal@hotmail.com
authors.forename: L
authors.initials: L
authors.lastname: Mutal
authors.forename: O
authors.initials: O
authors.lastname: Gani
mesh_terms: D001729:Bismuth; D002126:Calcium Hydroxide; D003907:Dexamethasone; D004338:Drug Combinations; D004853:Epoxy Resins; D005557:Formaldehyde; D005899:Glass Ionomer Cements; D006854:Hydrocortisone; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D036301:Qualitative Research; D012387:Root Canal Filling Materials; D012834:Silver; D013943:Thymol / Q000031:analogs & derivatives; D014025:Titanium; D015035:Zinc Oxide-Eugenol Cement
chemical_list: C074418:Apexit; D004338:Drug Combinations; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; C074934:Ketac Endo; D012387:Root Canal Filling Materials; C080620:Sealer 26; D015035:Zinc Oxide-Eugenol Cement; C011244:corticosteroid methanetriol mixture; C534916:epoxy resin-based root canal sealer; D005557:Formaldehyde; D013943:Thymol; D012834:Silver; C028044:epoxy resin AH-26; C048769:tubliseal; D003907:Dexamethasone; C076543:Kerr Pulp Canal Sealer; D014025:Titanium; D002126:Calcium Hydroxide; D001729:Bismuth; D006854:Hydrocortisone