title: Bacterial leakage versus dye leakage in obturated root canals.
abstract: OBJECTIVE
  The aim of this study was to compare in vitro bacterial and dye leakage tests, commonly used to determine the seal of root canal fillings.
  
  
  METHODS
  Ninety-six single-rooted teeth had their crowns removed at the cemento-enamel junction and their roots instrumented to ISO size 60 within 1 mm of the apex. Three groups of 30 roots were obturated by lateral condensation using gutta-percha and one or other of the sealers. AH26, Ketac Endo, or Roth's 801 sealer. Three roots were used as negative controls and three roots as positive controls. The roots were then exposed at their coronal end first for 38 days to soy broth containing Staphylococcus epidermidis and thereafter for 48 h to basic fuchsin. Bacterial leakage was recorded when the challenging organism could be recovered from the apical end. Dye leakage was checked by microscopy of transverse sections of the apical tip at the end of the experiment.
  
  
  RESULTS
  For the bacterial experiment, there was no significant difference amongst the three sealer groups. The dye experiment showed significantly greater leakage in the AH26 compared to the Ketac Endo group. No correlation between the results of the two tests could be seen.
  
  
  CONCLUSIONS
  The results of this study suggest that the molecular size of the penetrating agent may not be the relevant parameter when attempting to determine an appropriate test for the sealability of root canal fillings.
authors.affiliation: Department of Operative and Preventive Dentistry and Endodontics, Charité, Humboldt University, Berlin, Germany.
authors.forename: C R
authors.initials: CR
authors.lastname: Barthel
authors.forename: J
authors.initials: J
authors.lastname: Moshonov
authors.forename: G
authors.initials: G
authors.lastname: Shuping
authors.forename: D
authors.initials: D
authors.lastname: Orstavik
mesh_terms: D001729:Bismuth; D004396:Coloring Agents; D003763:Dental Leakage / Q000175:diagnosis*; D004338:Drug Combinations; D004853:Epoxy Resins; D005069:Evaluation Studies as Topic; D005899:Glass Ionomer Cements; D006801:Humans; D008709:Methenamine; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D012394:Rosaniline Dyes; D012834:Silver; D014025:Titanium; D015035:Zinc Oxide-Eugenol Cement
chemical_list: D004396:Coloring Agents; D004338:Drug Combinations; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; C074934:Ketac Endo; D012387:Root Canal Filling Materials; D012394:Rosaniline Dyes; D015035:Zinc Oxide-Eugenol Cement; D012834:Silver; C028044:epoxy resin AH-26; C074935:Roth's 801 Sealer; D014025:Titanium; D008709:Methenamine; D001729:Bismuth