title: Analysis of bond strength by pull out test on fiber glass posts cemented in different lengths.
abstract: BACKGROUND
  The aim of this study was to evaluate, by means of pull-out test, the bond strength of fiberglass posts when cemented with different lengths in endodontically treated teeth.
  
  
  METHODS
  Sixty single-rooted bovine roots were cut in the cementoenamel junction with 21 mm length. They were endodontically treated and randomly divided into three groups (n = 20). Group 1 - Preparation of 2/3 of the remaining roots; Group 2 - Preparation of ½ of the remaining roots and Group 3 - Preparation of ¼ of remaining roots. For all groups it were used posts n = 3 (Exacto, Angelus, Brazil), and cemented with self-etching resin cement (RelyXU200). After cementing posts, the samples were thermocycled (10.000 cycles/5°C and 55°C). The pull-out test was performed on a universal testing machine (EMIC - DL500) and the values obtained were statistically analyzed by analysis of variance (one-factor ANOVA) and multiple comparison test of Tukey, with level of significance of 5%.
  
  
  RESULTS
  The mean values ± standard deviation in Newtons (N) were: Group 1 = 120.5 (±42.8) A, Group 2 = 103.1 (±31.2) AB, Group 3 = 41.2 (±22.4) C, P < 0.005.
  
  
  CONCLUSIONS
  The preparation of ½ of remaining root appears to be a viable alternative when 2/3 of the preparation of the remaining root is not possible, but more results are needed for clinical validation.
authors.affiliation: Professor, Department of Prosthodontics, UNIOESTE, Cascavel, Paraná, Brazil.
authors.forename: Mariana Benedetti Ferreira
authors.initials: MB
authors.lastname: Webber
authors.affiliation: Professor, Department of Prosthodontics, Faculdade Ingá, Maringá, Paraná, Brazil.
authors.forename: Silvia Masae de Araújo
authors.initials: SM
authors.lastname: Michida
authors.affiliation: Professor, Department of Prosthodontics, Faculdade Ingá, Maringá, Paraná, Brazil.
authors.forename: Fabiano Carlos
authors.initials: FC
authors.lastname: Marson
authors.affiliation: Professor, Department of Prosthodontics, Faculdade Ingá, Maringá, Paraná, Brazil.
authors.forename: Giovani Corrêa
authors.initials: GC
authors.lastname: de Oliveira
authors.affiliation: Professor, Department of Prosthodontics, Faculdade Ingá, Maringá, Paraná, Brazil.
authors.forename: Cleverson de Oliveira E
authors.initials: Cde O
authors.lastname: Silva
keywords: Bond strength; fiber post; pull-out test; resin cements