title: Fracture strength of endodontically treated molars transfixed horizontally by a fiber glass post.
abstract: OBJECTIVE
  To assess the effect of a horizontally transfixed fiber glass post placed between buccal and palatal surfaces, on the fracture strength of endodontically treated molar teeth with MOD cavities, either restored with resin-based composite, or not.
  
  
  METHODS
  75 sound maxillary human third molars were extracted, embedded in acrylic resin blocks and randomly assigned to five groups (n=15). Group A (sound teeth), (control) and Groups B, C, D and E, which were subjected to the following procedures after endodontic treatment: GB--(MOD+Endo), GC--(MOD+Endo+Post), GD--MOD and composite restoration (MOD+Endo+CR), GE--(MOD+Endo+Post+CR). The specimens were stored in distilled water at 37 degrees C for 24 hours. Later, a compressive force was applied by means of a universal testing machine at 1 mm/minute speed, parallel to the long axis of the teeth until fracture occurred.
  
  
  RESULTS
  The means of the results (N) followed by the same letter represent no statistical difference by ANOVA and Tukey (P<0.05): GA = 4289.8 (+/- 1128.9)a, GB = 549.6 (+/- 120.7)b, GC = 1474.8 (+/- 338.1)c, GD = 1224.7 (+/- 236.0)c, GE = 2645.4 (+/- 675.1)d. In the analysis of qualitative variables, there was a tendency to cusp fracture in all groups except for Group C. The fiber glass post transfixed horizontally in a MOD cavity significantly increased the fracture resistance of the teeth restored with resin composite.
authors.affiliation: Department of Restorative Dentistry, Pontificia Universidade Católica do Rio Grande do Sul, Av. Ipiranga 6681, prédio 6, Faculdade de Odontologia, 90619-900-Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Maria Cecilia Gomes
authors.initials: MC
authors.lastname: Beltrão
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Spohr
authors.forename: Hugo Mitsuo Silva
authors.initials: HM
authors.lastname: Oshima
authors.forename: Eduardo Gonçalves
authors.initials: EG
authors.lastname: Mota
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Burnett
mesh_terms: D003188:Composite Resins; D019245:Compressive Strength; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D005898:Glass; D006801:Humans; D008964:Molar, Third; D011176:Post and Core Technique; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000517:prevention & control*; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D003188:Composite Resins; C009753:fiberglass