title: Fracture resistance of endodontically treated roots with oval canals restored with oval and circular posts.
abstract: BACKGROUND
  The aim of the present study was to evaluate the effects of post space preparations with circular and oval post drills and the placement of oval and circular posts on the fracture strength of roots with oval canals.
  
  
  METHODS
  Seventy mandibular premolars with oval root canals were decoronated. Fourteen teeth were used as a control group (group 1), and the root canals of the remaining teeth were prepared up to size #30. The root canals were filled, and the samples were randomly divided into 4 experimental groups as follows: post space preparation with circular-shaped drills (group 2), post space preparation with oval-shaped drills (group 3), circular post placement (group 4), and oval post placement (group 5). A fracture strength test was performed on each specimen, and the data were statistically evaluated using 1-way analysis of variance and Tukey post hoc tests.
  
  
  RESULTS
  The fracture strengths of the circular posts-placed group were higher than those of the oval post-placed group (P < .001). The post space preparation using oval-shaped drills significantly decreased the fracture strength of the roots compared with the control group (P < .001).
  
  
  CONCLUSIONS
  Within the limitations of the present study, oval posts did not provide a higher fracture resistance to endodontically treated roots with oval canals compared with circular posts. Therefore, clinicians should be aware that oval posts are similar to circular posts in terms of enhancing the fracture resistance of roots with oval canals.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: İsmail
authors.initials: İ
authors.lastname: Uzun
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Atatürk University, Erzurum, Turkey. Electronic address: pageofhakan@yahoo.com.
authors.forename: Hakan
authors.initials: H
authors.lastname: Arslan
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Atatürk University, Erzurum, Turkey.
authors.forename: Ezgi
authors.initials: E
authors.lastname: Doğanay
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: Buğra
authors.initials: B
authors.lastname: Güler
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: Cangül
authors.initials: C
authors.lastname: Keskin
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey.
authors.forename: Ismail Davut
authors.initials: ID
authors.lastname: Çapar
mesh_terms: D019232:Dental Restoration Failure; D006801:Humans; D012387:Root Canal Filling Materials; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012390:Root Canal Therapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D014082:Tooth Fractures / Q000209:etiology / Q000517:prevention & control*
chemical_list: D012387:Root Canal Filling Materials
keywords: Endodontically treated tooth; fiber post; fracture strength; oval fiber post