title: Microscopic appearance and apical seal of root canals filled with gutta-percha and ProRoot Endo Sealer after immersion in a phosphate-containing fluid.
abstract: OBJECTIVE
  To investigate the sealing quality of ProRoot Endo Sealer, a calcium silicate-based sealer and its morphologic characteristics after immersion in a phosphate-containing fluid (PCF).
  
  
  METHODS
  Single-rooted canals were filled with gutta-percha and either ProRoot Endo Sealer or two commercially available zinc oxide eugenol (ZOE)-based and epoxy resin-based sealers. The sealers were allowed to set for 6 days and the filled teeth were immersed in PCF for 24 h before fluid leakage evaluation. After initial leakage evaluation at the 7th day, each filled root was restored and reimmersed in PCF for 28 days before the second phase of leakage evaluation at 35 days. Cryofractured specimens of additional teeth filled with the three sealers were examined using scanning electron microscopy after immersion in PCF for the two periods.
  
  
  RESULTS
  One-way repeated measures anova and Tukey test revealed significant differences between the ZOE-based sealer at 35 days and the calcium silicate-based sealer at 35 days (P < 0.001), and between the ZOE-based sealer at 7 days and the calcium silicate-based sealer at 35 days (P = 0.001). No difference was found between the epoxy resin-based sealer and the calcium silicate-based sealer after both storage periods. Cryofractured calcium silicate-based sealer specimens demonstrated apatite-like crystalline deposits along the apical and middle thirds of the canal walls via transformation from amorphous calcium phosphate-like precursors.
  
  
  CONCLUSIONS
  ProRoot Endo Sealer is comparable in sealing quality to the epoxy resin-based sealer and seals better than the ZOE-based sealer after immersion in PCF. The calcium silicate-based sealer also demonstrates ex vivo bioactivity when it comes into contact with phosphate ions.
authors.affiliation: Department of Endodontics, School of Dentistry, Medical College of Georgia, Augusta, GA 30912-1129, USA.
authors.forename: R N
authors.initials: RN
authors.lastname: Weller
authors.forename: K C Y
authors.initials: KC
authors.lastname: Tay
authors.forename: L V
authors.initials: LV
authors.lastname: Garrett
authors.forename: S
authors.initials: S
authors.lastname: Mai
authors.forename: C M
authors.initials: CM
authors.lastname: Primus
authors.forename: J L
authors.initials: JL
authors.lastname: Gutmann
authors.forename: D H
authors.initials: DH
authors.lastname: Pashley
authors.forename: F R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D001031:Apatites / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry; D003460:Crystallization; D001840:Dental Bonding; D003763:Dental Leakage / Q000145:classification; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure; D004338:Drug Combinations; D004853:Epoxy Resins / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D019227:Tooth Apex / Q000648:ultrastructure; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: D017607:Aluminum Compounds; D001031:Apatites; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004338:Drug Combinations; D004853:Epoxy Resins; D010087:Oxides; D010710:Phosphates; D012387:Root Canal Filling Materials; D017640:Silicates; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; C086631:mineral trioxide aggregate; D006171:Gutta-Percha; C020243:calcium phosphate; C031293:calcium silicate