title: In vitro evaluation of a mechanical testing chewing simulator.
abstract: OBJECTIVE
  In this in vitro study, the force-profile of a commonly used chewing simulator (Williytec, Munich, Germany) utilizing fixed weights for loading was evaluated.
  
  
  METHODS
  Using piezoelectric force sensors the maximum and mean values of the applied forces were recorded in three different load configurations in order to determine the repetition accuracy in one test chamber. The variation in resulting forces of the eight test loading-chambers when using three different loads and descending speeds was explored.
  
  
  RESULTS
  The simulator showed high load repetition accuracy between the different cycle rates. Significant differences (up to 38.2+/-0.4N) were observed between the different specimen chambers. In addition, the recorded loads were generally both higher (up to 137.5+/-0.4N) and lower than the nominal loads defined by the static weights. The extent of load variation at contact was highly dependent on the descending cross-speed and selected weight. Finally there were also ringing in the load profiles attributed to vibrations of the mechanical setup.
  
  
  CONCLUSIONS
  Studies using weight-controlled chewing simulators should consider these effects when reporting results. In addition, calibrations should be performed to check uniformity of tests conditions for each test chamber.
authors.affiliation: Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts University Kiel, Arnold-Heller-Str. 16, 24105 Kiel, Germany. msteiner@proth.uni-kiel.de
authors.forename: Martin
authors.initials: M
authors.lastname: Steiner
authors.forename: Miltiadis E
authors.initials: ME
authors.lastname: Mitsias
authors.forename: Klaus
authors.initials: K
authors.lastname: Ludwig
authors.forename: Matthias
authors.initials: M
authors.lastname: Kern
mesh_terms: D001732:Bite Force; D019554:Dental Restoration Wear; D003799:Dental Stress Analysis / Q000295:instrumentation*; D008409:Mastication; D008422:Materials Testing / Q000295:instrumentation*; D012371:Robotics; D012815:Signal Processing, Computer-Assisted