title: Removing root canal obturation materials: a comparison of rotary file systems and re-treatment agents.
abstract: BACKGROUND
  The authors conducted a study to compare the effectiveness and working time of two rotary instrumentation file systems with two solvents for the removal of gutta-percha (GP) (ProTaper Universal, Dentsply Tulsa Dental, Tulsa, Okla.) or resin-based composite (RBC) (RealSeal 1 Bonded Obturator, SybronEndo, Orange, Calif.) endodontic obturation materials.
  
  
  METHODS
  The authors instrumented 88 human extracted teeth and obturated the root canals of 80 of the teeth with either GP with AH Plus root canal sealer (Dentsply Maillefer, Tulsa, Okla.) or RBC with adhesive according to the manufacturers' instructions. They re-treated each tooth by using one of two rotary instrumentation file systems. They assessed each file system by using chloroform or orange solvent re-treatment agents. The authors measured the time needed to remove the obturation material from each tooth. They processed the teeth for scanning electron microscopy, and two blinded reviewers categorized the micrographs according to several criteria.
  
  
  RESULTS
  The authors observed more RBC remnants on the root canal surfaces compared with GP remnants after re-treatment. The re-treatment solvents and file systems were equally effective in removing the obturation materials.
  
  
  CONCLUSIONS
  The study results show that the quickest root canal retreatment can be accomplished by using EndoSequence rotary files (Brasseler, Savannah, Ga.) and orange solvent to remove RBC obturation material.
  
  
  CONCLUSIONS
  Re-treatment with EndoSequence rotary files was quicker than re-treatment with ProTaper Universal re-treatment files (Dentsply Tulsa Dental). However, in this study, the file systems were similarly effective in removing GP and RBC. Orange solvent was as effective as chloroform in removing obturation materials, but its use is less time-consuming.
authors.affiliation: Department of Endodontics, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, Fla. 33328, USA.
authors.forename: Jamie
authors.initials: J
authors.lastname: Ring
authors.forename: Peter E
authors.initials: PE
authors.lastname: Murray
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Namerow
authors.forename: B Ivan
authors.initials: BI
authors.lastname: Moldauer
authors.forename: Franklin
authors.initials: F
authors.lastname: Garcia-Godoy
mesh_terms: D002725:Chloroform / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure; D004853:Epoxy Resins / Q000737:chemistry; D004867:Equipment Design; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008855:Microscopy, Electron, Scanning; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation*; D016369:Smear Layer; D012997:Solvents / Q000737:chemistry*; D013997:Time Factors
chemical_list: D003188:Composite Resins; D004853:Epoxy Resins; C511498:Real Seal composite resin; D012387:Root Canal Filling Materials; D012997:Solvents; C534916:epoxy resin-based root canal sealer; D002725:Chloroform; D006171:Gutta-Percha