title: Effect of bonded area and/or fiber post placement on the fracture strengths of resin-core reconstructions for pulpless teeth.
abstract: OBJECTIVE
  To compare the fracture strengths of pulpless teeth restored using resin cores with and without fiber posts, and with and without bonding adhesive in the post cavity.
  
  
  METHODS
  Human extracted roots were prepared with post cavities and divided into four experimental groups: Groups 1 and 2--after application of adhesive to both the top surface of the root and the inner surface of the post cavity, DC core Automix was injected into the post space with or without fiber-post placement; Groups 3 and 4--adhesive was applied to the top surface of the root only, with or without post placement. Resin-cores were then built-up. Teeth prepared for full crowns served as controls. After water storage at 37 degrees C for 24 hours, the all specimens were embedded in acrylic resin at 2 mm below CEJ, and loaded at 45 degrees to the long axis of the tooth using a universal testing machine until fracture. The data were analyzed by one-way ANOVA (alpha = 0.05).
  
  
  RESULTS
  The fracture loads were, Group 1: 1832 +/- 240 N, Group 2: 1815 +/- 347 N, Group 3: 1626 +/- 396 N, Group 4: 1810 +/- 332 N, Control Group: 1622 +/- 274 N. There were no significant differences among all the groups (P > 0.05).
authors.affiliation: Department of Restorative Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. nakajima.ope@tmd.ac.jp
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakajima
authors.forename: Tama
authors.initials: T
authors.lastname: Kanno
authors.forename: Wataru
authors.initials: W
authors.lastname: Komada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miura
authors.forename: Richard M
authors.initials: RM
authors.lastname: Foxton
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D005898:Glass; D006801:Humans; D011176:Post and Core Technique; D019279:Resin Cements; D014082:Tooth Fractures / Q000517:prevention & control; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C009753:fiberglass