title: Retreatability of a bioceramic root canal sealing material.
abstract: BACKGROUND
  The efficacy of retreatment techniques for BC Sealer (BCS) (Brasseler USA, Savannah, GA) removal has not yet been assessed. The purpose of this study was to evaluate the efficacy of solvent and rotary instrumentation in the removal of BCS when used in combination with gutta-percha (GP) as compared with AH Plus sealer (Dentsply, Tulsa, OK).
  
  
  METHODS
  The mesiobuccal canals of 40 mandibular molars were instrumented and obturated with either GP/AH Plus with warm vertical compaction or GP/BCS using a single cone. The groups were subdivided into samples with the master GP cone placed to the working length (WL) or intentionally 2 mm short of the WL. Canals were then retreated using heat, chloroform, rotary instruments, and hand files. The ability to regain the WL and patency were evaluated as well as the time required to remove obturation material. Representative samples were also analyzed via scanning electron microscopy.
  
  
  RESULTS
  The WL was not regained in 70% of samples with BCS/master cone short of the WL. Patency was not re-established in 20% of samples with BCS/master cone to the WL or in 70% of samples with BCS/master cone short of the WL.
  
  
  CONCLUSIONS
  Conventional retreatment techniques are not able to fully remove BCS.
authors: Department of Endodontics, Baylor College of Dentistry, The Texas A&M University System Health Science Center, Dallas, Texas, USA.
authors: Darren
authors: D
authors: Hess
authors: Eric
authors: E
authors: Solomon
authors: Robert
authors: R
authors: Spears
authors: Jianing
authors: J
authors: He
mesh_terms: D002516:Ceramics; D004853:Epoxy Resins; D006171:Gutta-Percha; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008963:Molar; D019233:Retreatment; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012997:Solvents; D018709:Statistics, Nonparametric; D013997:Time Factors; D019227:Tooth Apex
chemical_list: D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D012997:Solvents; C534916:epoxy resin-based root canal sealer; D006171:Gutta-Percha