title: [Resistance to cyclic fatigue of pulpless teeth with flared root canals restored with different post-and-core materials].
abstract: OBJECTIVE
  To investigate the resistance to cyclic fatigue of maxillary incisors with flared canals restored with different post-and-core materials.
  
  
  METHODS
  Thirty human maxillary central incisors were assigned randomly to two main groups (non-ferrule and 1-mm ferrule) of 15. Each main group was then divided into 3 groups of 5 specimens and restored with custom cast post-and-core (MPC), resin composite post-and-core (RCP), and resin composite core combined with prefabricated carbon fiber post (FRC), respectively. Every group was subjected to a cyclic fatigue test, and recorded the numbers of load cycles that occurred tooth fracture. All data were analyzed with two-way ANOVA and the Tukey HSD test at alpha = 0.05.
  
  
  RESULTS
  FRC revealed significantly higher fatigue strength than the other groups (P < 0.05). Preparing a dentin ferrule increased significantly fatigue resistance (P < 0.05). The favorable (retrieval) fracture pattern of the tested specimens was discovered only in RCP.
  
  
  CONCLUSIONS
  Using FRC may get a long fatigue life in restoring pulpless teeth with flared canals. Dentin ferrule preparation is necessary to enhance resistance of the restorations to cyclic fatigue.
authors.affiliation: Department of Dental Technology, College of Stomatology, Dalian Medical University, Dalian 116027, China. shuhaihu4141@yahoo.com.cn
authors.forename: Shu-hai
authors.initials: SH
authors.lastname: Hu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Osada
authors.forename: Kenji
authors.initials: K
authors.lastname: Warita
authors.forename: Tadaharu
authors.initials: T
authors.lastname: Kawawa
mesh_terms: D002244:Carbon; D000077482:Carbon Fiber; D002858:Chromium Alloys; D003188:Composite Resins; D003764:Dental Materials; D003786:Dental Pulp Cavity / Q000473:pathology*; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D000077482:Carbon Fiber; D002858:Chromium Alloys; D003188:Composite Resins; D003764:Dental Materials; D002244:Carbon