title: Evaluation of push-out bond strength of two endodontic post systems.
abstract: BACKGROUND
  The aim of this study was to evaluate the push-out bond strengths of a new polyfiber post system and a fiber post that were adhesively luted with a dual-cure resin cement.
  
  
  METHODS
  Forty single-rooted human maxillary teeth were sectioned below the cementoenamel junction, and the roots were endodontically treated. The roots were randomly divided into 2 groups of 20 specimens each according to the post type used: SpiraPost (group A; DMG, Englewood, NJ) and DT Light-Post Illusion X-RO (group B; Bisco Inc, Schaumburg, IL). All posts were cemented with dual-cure resin cement. Bonded specimens were cut into 1-mm-thick sections, and push-out tests were performed using a universal testing machine. All specimens were loaded until fracture, and the failure modes were evaluated with a stereomicroscope at 50× magnification. Representative specimens were analyzed by scanning electron microscopy.
  
  
  RESULTS
  Push-out bond strength was significantly affected by the type of post (P < .05). In all root sections, the SpiraPost push-out bond strength values were significantly higher than that those of DT Light-Post Illusion X-RO (P < .05). Cohesive failure within the post was the most frequent type of failure for the SpiraPost system.
  
  
  CONCLUSIONS
  In all root segments, the SpiraPost system provided significantly increased post retention compared with the fiber post.
authors.affiliation: Department of Endodontics, Division of Pathology and Therapeutics of Dental Tissues and Basic Dental Sciences, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. kmastoras@gmail.com
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Mastoras
authors.forename: Leonidas
authors.initials: L
authors.lastname: Vasiliadis
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Koulaouzidou
authors.forename: Christos
authors.initials: C
authors.lastname: Gogos
mesh_terms: D000268:Adhesiveness; D000328:Adult; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011176:Post and Core Technique / Q000295:instrumentation*; D011791:Quartz / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D018915:Root Canal Preparation / Q000379:methods; D055116:Self-Curing of Dental Resins; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019553:Tooth, Nonvital / Q000473:pathology
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; D011791:Quartz