title: Rotational fatigue-resistance of seven post types anchored on natural teeth.
abstract: OBJECTIVE
  To develop a laboratory model aimed at duplicating the failure process of post and core restorations. The load pattern applied was to be repetitive (fatigue) and multivectorial. To determine and compare the resistance under fatigue loading of seven endodontic post/natural root combinations: stainless steel-, titanium-, ceramic-, composite-fiber/epoxy-, two glass-fiber/epoxy- and glass-fiber/acrylic posts.
  
  
  METHODS
  The repetitive, alternating and multivectorial intraoral force pattern was reproduced by subjecting the specimens to the rotating cantilever beam test. To this end, the samples were designed as rotation-symmetric structures comprising a root, a post, periodontal ligament- and bone analogs and a restoration analog. The following posts were tested: Unimetric-Ti, Unimetric-SS, Biopost, Composipost, Easypost, DT Lightpost, Everstickpost. The samples were spun around their long axes while being clamped into a revolving collet on one end and loaded normal to their long axis on the other end. The aim was to determine the load level at which 50% of the specimens survived- and 50% fractured before 10E6 cycles. The 50% means were determined using the staircase procedure.
  
  
  RESULTS
  In increasing order of magnitude, the resistances to fatigue loading were as follows: Biopost, Unimetric-Ti, Unimetric-SS, Composipost, Easypost, Everstickpost, DT Lightpost.
  
  
  CONCLUSIONS
  The fatigue resistance of the two fibrous posts with the highest fatigue resistance was twice that of any of the ceramic or metal posts.
authors.affiliation: Department of Prosthodontics-Biomaterials, School of Dental Medicine, University of Geneva, 19, rue Barthélemy-Menn, 1205 Geneva, Switzerland. anselm@wiskott.com
authors.forename: H W Anselm
authors.initials: HW
authors.lastname: Wiskott
authors.forename: Malika
authors.initials: M
authors.lastname: Meyer
authors.forename: Jean
authors.initials: J
authors.lastname: Perriard
authors.forename: Susanne S
authors.initials: SS
authors.lastname: Scherrer
mesh_terms: D002516:Ceramics; D003188:Composite Resins; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D008670:Metals; D003765:Models, Dental; D011176:Post and Core Technique; D012399:Rotation
chemical_list: D003188:Composite Resins; D008670:Metals