title: A finite element evaluation of mechanical function for 3 distal extension partial dental prosthesis designs with a 3-dimensional nonlinear method for modeling soft tissue.
abstract: BACKGROUND
  The mechanical evaluation of the function of partial removable dental prostheses with 3-dimensional finite element modeling requires the accurate assessment and incorporation of soft tissue behavior. The differential behaviors of the residual ridge mucosa and periodontal ligament tissues have been shown to exhibit nonlinear displacement. The mathematic incorporation of known values simulating nonlinear soft tissue behavior has not been investigated previously via 3-dimensional finite element modeling evaluation to demonstrate the effect of prosthesis design on the supporting tissues.
  
  
  OBJECTIVE
  The purpose of this comparative study was to evaluate the functional differences of 3 different partial removable dental prosthesis designs with 3-dimensional finite element analysis modeling and a simulated patient model incorporating known viscoelastic, nonlinear soft tissue properties.
  
  
  METHODS
  Three different designs of distal extension removable partial dental prostheses were analyzed. The stress distributions to the supporting abutments and soft tissue displacements of the designs tested were calculated and mechanically compared.
  
  
  RESULTS
  Among the 3 dental designs evaluated, the RPI prosthesis demonstrated the lowest stress concentrations on the tissue supporting the tooth abutment and also provided wide mucosa-borne areas of support, thereby demonstrating a mechanical advantage and efficacy over the other designs evaluated.
  
  
  CONCLUSIONS
  The data and results obtained from this study confirmed that the functional behavior of partial dental prostheses with supporting abutments and soft tissues are consistent with the conventional theories of design and clinical experience. The validity and usefulness of this testing method for future applications and testing protocols are shown.
authors.affiliation: Associate Professor, Department of Removable Prosthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Assistant Professor, Department of Removable Prosthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan. Electronic address: ryo1221@dpc.agu.ac.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kanbara
authors.affiliation: Clinical Professor, Ostrow School of Dentistry of USC, University of Southern California, Los Angeles, Calif.
authors.forename: Kent T
authors.initials: KT
authors.lastname: Ochiai
authors.affiliation: Professor, Department of Removable Prosthodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000539:Alveolar Process / Q000502:physiology; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D000044:Dental Abutments; D016734:Dental Clasps; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation; D003832:Denture, Partial, Removable; D004548:Elasticity; D020342:Finite Element Analysis; D005881:Gingiva / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008334:Mandible / Q000502:physiology; D008953:Models, Anatomic; D008954:Models, Biological; D017711:Nonlinear Dynamics; D010513:Periodontal Ligament / Q000502:physiology*; D013314:Stress, Mechanical; D014783:Viscosity