title: Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison.
abstract: OBJECTIVE
  Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis.
  
  
  METHODS
  Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and apost-hocTukey test. Fisher exact tests were performed to analyze the ability to regain patency.
  
  
  RESULTS
  There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group.
  
  
  CONCLUSIONS
  The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform.
authors.affiliation: Department of Endodontics, University of Washington, Seattle, WA, USA.
authors.forename: Enrique
authors.initials: E
authors.lastname: Oltra
authors.affiliation: Department of Pediatrics (Craniofacial Medicine), University of Washington, Seattle, WA, USA.; Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.; Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Cox
authors.affiliation: Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: LaCourse
authors.affiliation: Department of Endodontics, University of Washington, Seattle, WA, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Johnson
authors.affiliation: Department of Endodontics, University of Washington, Seattle, WA, USA.
authors.forename: Avina
authors.initials: A
authors.lastname: Paranjpe
keywords: AH Plus; BC Sealer; Chloroform; Endodontic sealers; Micro-CT; Retreatability