title: [Comparison of fracture resistance of pulpless teeth restored with fiber reinforced composite posts and three kinds of resin core material].
abstract: OBJECTIVE
  To compare the fracture resistances of pulpless teeth restored with FRC (Fiber Reinforced Composite) posts and three kinds of resin core material.
  
  
  METHODS
  A total of 42 recently extracted upper incisors were randomly divided into 3 groups. Group A was restored with prefabricated glass-fiber posts and Artglass polymer core; group B with prefabricated glass-fiber posts and Charisma composite resin core; and group C with prefabricated glass-fiber posts and AB composite resin core. In every group, the core material was processed by hot-press and non hot-press respectively. The posts size and shape were identical in the 3 groups. All teeth were fully covered with polycarbonate resin crowns. Fracture resistance was measured by applying point force at 130 degrees to the long axis of the teeth on an universal testing machine.
  
  
  RESULTS
  Mean fracture threshold was 505.4 N +/- 42.0 N and 564.1 N +/- 41.7 N in group A, 411.3 N +/- 23.3 N and 315.3 N +/- 19.1 N in group B and 358.4 N +/- 36.1 N and 423.4 N +/- 47.5 N in group C. In all groups, there was no posts fracture and polycarbonate resin crowns fragmentation.
  
  
  CONCLUSIONS
  The composite restoration of FRC posts combined with resin core and resin crown can improve the fracture resistance of the pulpless roots. The strength of resin core material can be increased by hot-press methods.
authors.affiliation: Dept. of Stomatology, Kunming General Hospital, Chengdu Military Region, Kunming 650032, China.
authors.forename: Wen-yun
authors.initials: WY
authors.lastname: Zhang
authors.forename: Ji-hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Chang-xi
authors.initials: CX
authors.lastname: Shi
authors.forename: An-qi
authors.initials: AQ
authors.lastname: Jia
authors.forename: Li-dou
authors.initials: LD
authors.lastname: Yang
mesh_terms: D003188:Composite Resins; D003442:Crowns; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D006801:Humans; D011176:Post and Core Technique; D014082:Tooth Fractures / Q000517:prevention & control; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D003188:Composite Resins