title: Comparison of deformation by stereophotogrammetry of various kinds of major connectors in maxillary Kennedy Class I removable partial dentures.
abstract: OBJECTIVE
  Major connectors must be rigid to perform their functions with maximum efficacy. This study investigated the deformation of four major connectors for maxillary Kennedy Class I removable partial dentures.
  
  
  METHODS
  The designs were palatal plate, U-shaped plate, palatal strap, and anteroposterior bar. The deformation properties of major connectors were comparatively analyzed by two methods. In the photogrammetric part, a stereometric camera, Avipan-100 glass films, and an analytic apparatus were used. A computerized hydraulic machine was programmed to load the eight test dentures at 4-Hz frequency under a vertical load of 100 kg and a maximum of 300,000 cycles. The fluorescence penetrant liquid inspection test was used to detect the surface microcracks.
  
  
  RESULTS
  The anteroposterior bar showed the least deformation. The other connectors, ranked in increasing order for the amount of deformation, were the U-shaped plate, the palatal strap, and the palatal plate. There were no microcracks in the U-shaped plate and the anteroposterior bar designs.
  
  
  CONCLUSIONS
  Anteroposterior bar major connectors showed the least deformation among the maxillary major connector types tested. Microscopic cracks were seen in major connectors showing the highest degree of deformation and located at the depth of the hard palate.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ankara University, Turkey. pozkan12@hotmail.com
authors.forename: P
authors.initials: P
authors.lastname: Ozkan
authors.forename: A K
authors.initials: AK
authors.lastname: Aydin
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D002858:Chromium Alloys / Q000737:chemistry; D003201:Computers; D003779:Denture Design; D003832:Denture, Partial, Removable; D005456:Fluorescent Dyes; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000145:classification* / Q000534:rehabilitation; D008422:Materials Testing; D008437:Maxilla; D010780:Photogrammetry / Q000295:instrumentation; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D016474:Weight-Bearing
chemical_list: D000180:Acrylic Resins; D002858:Chromium Alloys; D005456:Fluorescent Dyes