title: Effect of anti-rotation devices on biomechanical behaviour of teeth restored with cast post-and-cores.
abstract: OBJECTIVE
  To test the hypothesis that the presence of an anti-rotation device (ARD) and its location can influence the biomechanical behaviour of root filled teeth restored with cast post-and-cores and metallic crowns.
  
  
  METHODS
  Fifth two bovine incisor roots were selected and divided into four groups (n = 13): Nd- without ARD; Bd- buccal ARD; Ld- lingual ARD; BLd- buccal and lingual ARD. The specimens were restored with cast post-and-cores and metallic crowns. After a fatigue process (3 x 10(5) 50 N), three strain gauges were attached on the buccal, lingual and proximal surfaces and the samples of each group (n = 3) were submitted to a 0-100 N load. Fracture resistance was assessed in a mechanical testing machine (n = 10). Strain values and fracture resistance data were analysed by one-way anova and Tukey Honestly Significant Difference (HSD) test (alpha = 0.05). The failure mode was then evaluated under an optical stereomicroscope. Bidimensional models of each group were generated for finite element analysis (FEA) and analysed using the von Mises criteria.
  
  
  RESULTS
  No significant difference in fracture resistance values and fracture modes occurred between the four groups. The BLd group had higher stress concentrations in the buccal dentine and higher strain values on the proximal surfaces.
  
  
  CONCLUSIONS
  The anti-rotation devices did not influence significantly the fracture resistance and fracture mode. However, the stress-strain values were increased when the anti-rotation device was prepared on the buccal and lingual faces concomitantly.
authors.affiliation: Department of Operative Dentistry and Dental Materials, Biomechanics Group, Federal University of Uberlândia, Minas Gerais, Brazil.
authors.forename: L H A
authors.initials: LH
authors.lastname: Raposo
authors.forename: G R
authors.initials: GR
authors.lastname: Silva
authors.forename: P C F
authors.initials: PC
authors.lastname: Santos-Filho
authors.forename: P V
authors.initials: PV
authors.lastname: Soares
authors.forename: P B F
authors.initials: PB
authors.lastname: Soares
authors.forename: P C
authors.initials: PC
authors.lastname: Simamoto-Junior
authors.forename: A J
authors.initials: AJ
authors.lastname: Fernandes-Neto
authors.forename: C J
authors.initials: CJ
authors.lastname: Soares
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D003442:Crowns; D003799:Dental Stress Analysis / Q000379:methods; D020342:Finite Element Analysis; D011176:Post and Core Technique / Q000295:instrumentation*; D012399:Rotation; D014082:Tooth Fractures / Q000517:prevention & control; D019553:Tooth, Nonvital / Q000503:physiopathology*