title: Impact of implant support on mandibular free-end base removable partial denture: theoretical study.
abstract: OBJECTIVE
  This study investigated the impact of implant support on the development of shear force and bending moment in mandibular free-end base removable partial dentures (RPDs).
  
  
  METHODS
  Three theoretical test models of unilateral mandibular free-end base RPDs were constructed to represent the base of tooth replacement, as follows: Model 1: first and second molars (M1 and M2); Model 2: second premolar (P2), M1, and M2; and Model 3: first premolar (P1), P2, M1, and M2. The implant support located either at M1 or M2 sites. The occlusal loading was concentrated at each replacement tooth to calculate the stress resultants developed in the RPD models using the free-body diagrams of shear force and bending moment.
  
  
  RESULTS
  There was a trend of reduction in the peak shear force and bending moment when the base was supported by implant. However, the degree of reduction varied with the location of implant support. The moment reduced by 76% in Model 1, 58% in Model 2, and 42% in Model 3, when the implant location shifted from M1 to M2 sites.
  
  
  CONCLUSIONS
  The shear forces and bending moments subjected to mandibular free-end base RPDs were found to decrease with the addition of implant support. However, the impact of implant support varied with the location of implant in this theoretical study.
authors.affiliation: Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA.
authors.forename: Won-suk
authors.initials: WS
authors.lastname: Oh
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.
authors.forename: Tae-Ju
authors.initials: TJ
authors.lastname: Oh
authors.affiliation: Department of Prosthodontics, Chonbuk National University School of Dentistry Research Institute of Clinical Medicine Chonbuk National University-Biomedical, Research Institute of Chonbuk National University Hospital Jeonju, South Korea.
authors.forename: Ju-mi
authors.initials: JM
authors.lastname: Park
mesh_terms: D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003779:Denture Design; D003832:Denture, Partial, Removable; D006801:Humans; D008334:Mandible; D008962:Models, Theoretical
keywords: bending moment; force; implant; removable partial denture; support