title: Three-dimensional finite element analysis of implant-assisted removable partial dentures.
abstract: BACKGROUND
  Whether the implant abutment in implant-assisted removable partial dentures (IARPDs) functions as a natural removable partial denture (RPD) tooth abutment is unknown.
  
  
  OBJECTIVE
  The purpose of this 3-dimensional finite element study was to analyze the biomechanical behavior of implant crown, bone, RPD, and IARPD.
  
  
  METHODS
  Finite element models of the partial maxilla, teeth, and prostheses were generated on the basis of a patient's computed tomographic data. The teeth, surveyed crowns, and RPDs were created in the model. With the generated components, four 3-dimensional finite element models of the partial maxilla were constructed: tooth-supported RPD (TB), implant-supported RPD (IB), tooth-tissue-supported RPD (TT), and implant-tissue-supported RPD (IT) models. Oblique loading of 300 N was applied on the crowns and denture teeth. The von Mises stress and displacement of the denture abutment tooth and implant system were identified.
  
  
  RESULTS
  The highest von Mises stress values of both IARPDs occurred on the implants, while those of both natural tooth RPDs occurred on the frameworks of the RPDs. The highest von Mises stress of model IT was about twice that of model IB, while the value of model TT was similar to that of model TB. The maximum displacement was greater in models TB and TT than in models IB and IT. Among the 4 models, the highest maximum displacement value was observed in the model TT and the lowest value was in the model IB.
  
  
  CONCLUSIONS
  Finite element analysis revealed that the stress distribution pattern of the IARPDs was different from that of the natural tooth RPDs and the stress distribution of implant-supported RPD was different from that of implant-tissue-supported RPD. When implants are used for RPD abutments, more consideration concerning the RPD design and the number or location of the implant is necessary.
authors.affiliation: Graduate student, Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
authors.forename: Ju-Won
authors.initials: JW
authors.lastname: Eom
authors.affiliation: Professor, Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Lim
authors.affiliation: Associate Professor, Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
authors.forename: Myung-Joo
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Associate Professor, Dental Research Institute and Department of Prosthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea. Electronic address: proskwon@snu.ac.kr.
authors.forename: Ho-Beom
authors.initials: HB
authors.lastname: Kwon
mesh_terms: D001696:Biomechanical Phenomena; D003442:Crowns; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003832:Denture, Partial, Removable; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional