title: Effect of dowel length on the retention of 2 different prefabricated posts.
abstract: OBJECTIVE
  To compare in vitro the retentive values of stainless steel, parallel-sided posts to quartz-fiber, tapered posts for 2 different dowel lengths (5 and 10 mm).
  
  
  METHODS
  Both post systems were cemented with a dual-cure adhesive resin cement. Single-rooted extracted human teeth (n = 40) were decoronated and randomly divided into 4 groups of 10 samples each. Posts of 5 and 10 mm in length were luted with the resin cement. Each sample was placed on a universal testing machine, and using a push-out method, a vertical load was applied at a crosshead speed of 2 mm/min. The amount of force required to dislodge the post was recorded. The effect of post type and length was evaluated using a 2-way analysis of variance.
  
  
  RESULTS
  A statistically significant main effect was found for post length (P <.001), with the 10-mm posts of both post systems requiring greater force to dislodge than the 5-mm posts. There was no interaction between post length and post type (P >.05).
  
  
  CONCLUSIONS
  It is concluded from this study that there is no statistical difference in retention between quartz-fiber, tapered posts and stainless steel, parallel-sided posts when they are cemented with the same resin cement (P >.05). The study also concludes that adequate retentive values are achieved with both post systems at the shorter, 5-mm post length.
authors.affiliation: Department of Endodontics, University of Florida, College of Dentistry, Gainesville, FL 32610-0436, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Borer
authors.forename: Leandro R
authors.initials: LR
authors.lastname: Britto
authors.forename: James E
authors.initials: JE
authors.lastname: Haddix
mesh_terms: D000704:Analysis of Variance; D003738:Dental Cements / Q000627:therapeutic use; D017268:Dental Prosthesis Retention / Q000379:methods*; D006801:Humans; D011176:Post and Core Technique
chemical_list: D003738:Dental Cements