title: Effectiveness of hand and rotary instrumentation for removing a new synthetic polymer-based root canal obturation material (Epiphany) during retreatment.
abstract: OBJECTIVE
  To evaluate the effectiveness of hand and rotary instrumentation for removal of vertically compacted Epiphany and gutta-percha during retreatment.
  
  
  METHODS
  Sixty extracted single-rooted maxillary central incisors were enlarged to size 40 using FlexMaster instruments. The teeth were randomly divided into four groups of 15 specimens each. The canals of two groups were obturated using vertically compacted Epiphany. The others were filled with vertically compacted gutta-percha and AH Plus sealer. One Epiphany group and one gutta-percha group was reinstrumented with Gates Glidden burs and Hedström files. In the other two groups, obturation material was removed using Gates Glidden burs and RaCe rotary instruments. After clearing the roots, the area of remaining obturation material on the root canal wall was measured using a computer image analysis program. Statistical analysis was performed using Repeated Measures Analysis of Variance and anova.
  
  
  RESULTS
  Retreatment of specimens obturated with gutta-percha showed significantly more remaining obturation material than specimens filled with Epiphany (P < 0.05). No difference was found between the removal with Hedström files and with RaCe instruments (P > 0.05). Regarding the mean time of retreatment and time required for reaching the working length, Hedström files were significantly faster than RaCe instruments (P < 0.05). The times did not depend on the kind of obturation material (P > 0.05).
  
  
  CONCLUSIONS
  Vertically compacted Epiphany in combination with Epiphany Root Canal Sealant was removed more effectively than gutta-percha and AH Plus sealer. Hedström files were more rapid than RaCe rotary instruments.
authors.affiliation: Department of Operative Dentistry and Periodontology, Albert-Ludwigs-University, Hugstetter Strasse 55, D-79106 Freiburg, Germany. joerg.schirrmeister@uniklinik-freiburg.de
authors.forename: J F
authors.initials: JF
authors.lastname: Schirrmeister
authors.forename: K M
authors.initials: KM
authors.lastname: Meyer
authors.forename: P
authors.initials: P
authors.lastname: Hermanns
authors.forename: M J
authors.initials: MJ
authors.lastname: Altenburger
authors.forename: K-T
authors.initials: KT
authors.lastname: Wrbas
mesh_terms: D003786:Dental Pulp Cavity / Q000648:ultrastructure; D004853:Epoxy Resins / Q000737:chemistry; D004867:Equipment Design; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor; D008422:Materials Testing; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation*; D012399:Rotation; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004853:Epoxy Resins; D012387:Root Canal Filling Materials; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer; D006171:Gutta-Percha