title: Efficacy of three different rotary files to remove gutta-percha and Resilon from root canals.
abstract: OBJECTIVE
  To evaluate the efficacy of ProTaper Retreatment files, Mtwo Retreatment files and Twisted Files for removal of gutta-percha and Resilon in straight root canals.
  
  
  METHODS
  Ninety single root canals were instrumented and randomly allocated into 6 groups of 15 specimens each with regards to the filling material and instruments used. Group 1: gutta-percha/ProTaper; Group 2: Resilon/ProTaper; Group 3: gutta-percha/Mtwo; Group 4: Resilon/Mtwo; Group 5: gutta-percha/Twisted Files; Group 6: Resilon/Twisted Files. For all roots, the following data were recorded: procedural errors, duration of retreatment, canal wall cleanliness through optical microscope and cone beam computed tomography (CBCT). Data were statistically analysed, and the level of significance was set at P=0.05.
  
  
  RESULTS
  No system completely removed the root filling material from root canal walls. No significant differences were observed between the rotary systems in terms of the area of filling material left within the canals (P>0.05). There were statistically significant differences between the filling materials: Resilon/Real Seal had less residual material than gutta-percha/AH plus (CBCT: P=0.01; microscope: P=0.018). Mtwo Retreatment files were more rapid when removing filling material than ProTaper Retreatment files (P=0.19) and Twisted Files (P=0.04).
  
  
  CONCLUSIONS
  No system removed the root filling materials entirely. Mtwo Retreatment files required less time to remove root filling material than the other instruments. Resilon was removed significantly better from the canal walls than gutta-percha, irrespective of the rotary instruments used.
authors: Department of Endodontics, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Barcelona, Spain.
authors: K
authors: K
authors: Marfisi
authors: M
authors: M
authors: Mercade
authors: G
authors: G
authors: Plotino
authors: F
authors: F
authors: Duran-Sindreu
authors: R
authors: R
authors: Bueno
authors: M
authors: M
authors: Roig
mesh_terms: D002614:Chelating Agents / Q000627:therapeutic use; D003188:Composite Resins / Q000737:chemistry; D054893:Cone-Beam Computed Tomography; D003786:Dental Pulp Cavity / Q000473:pathology*; D003804:Dentin / Q000473:pathology; D004492:Edetic Acid / Q000627:therapeutic use; D004853:Epoxy Resins / Q000737:chemistry; D004867:Equipment Design; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013499:Surface Properties; D013997:Time Factors; D019227:Tooth Apex / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D002614:Chelating Agents; D003188:Composite Resins; D004853:Epoxy Resins; C511498:Real Seal composite resin; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C534916:epoxy resin-based root canal sealer; C486892:resilon sealer; D006171:Gutta-Percha; D004492:Edetic Acid; D012973:Sodium Hypochlorite