title: Leakage associated with intermediate restorative material and glass-ionomer cement retrograde fillings: a human and sheep teeth comparison with 2 different aging procedures.
abstract: OBJECTIVE
  Leakage around retrograde fillings is an important cause of endodontic surgery. This in vitro study sought to compare the following: (1) methylene blue dye leakage linked to retrofillings in human and sheep teeth with the degree of dye penetration when intermediate restorative materials and Chemfil were used as retrofillings, (2) the apical microleakage in filled with that in unfilled root canals, and (3) 2 storage techniques, incubator-based and subcutaneous implantation in rats.
  
  
  METHODS
  Tested were 198 human and 196 sheep teeth that were retrofilled with intermediate restorative material or Chemfil, then stored in an incubator or subcutaneously in rats for 10, 20, and 30 days before immersion in methylene blue dye for 24 hours. Linear dye penetration was evaluated, and the results were statistically analyzed by means of analysis of variance.
  
  
  RESULTS
  Leakage between sheep and human teeth was significantly different (P <.05). Chemfil had significantly less leakage than intermediate restorative material after storage in rat (P <.05) for up to 20 days, but not after 30 days. No differences were found between leakage of unfilled and filled human root canal teeth.
  
  
  CONCLUSIONS
  The sheep incisor is a poor experimental model of the human tooth, and both aging procedures demonstrate extensive leakage of retrofilling materials after long-term storage.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Université d'Auvergne Clermont1, Clermont-Ferrand, France. Dominique.Roux@u-clermont1.fr
authors.forename: Dominique
authors.initials: D
authors.lastname: Roux
authors.forename: Sophie
authors.initials: S
authors.lastname: Doméjean-Orliaguet
authors.forename: Marwan
authors.initials: M
authors.lastname: Saade
mesh_terms: D000538:Aluminum Silicates / Q000009:adverse effects; D000818:Animals; D004396:Coloring Agents; D003763:Dental Leakage / Q000175:diagnosis / Q000209:etiology*; D004356:Drug Storage; D005899:Glass Ionomer Cements / Q000009:adverse effects*; D006801:Humans; D008751:Methylene Blue; D008768:Methylmethacrylates / Q000009:adverse effects; D051381:Rats; D012184:Retrograde Obturation / Q000009:adverse effects*; D012387:Root Canal Filling Materials / Q000009:adverse effects*; D012756:Sheep; D018709:Statistics, Nonparametric; D013997:Time Factors; D015035:Zinc Oxide-Eugenol Cement / Q000009:adverse effects
chemical_list: D000538:Aluminum Silicates; D004396:Coloring Agents; D005899:Glass Ionomer Cements; D008768:Methylmethacrylates; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C031667:IRM cement; C039733:Chemfil; D008751:Methylene Blue