title: Effect of platform switching on implant crest bone stress: a finite element analysis.
abstract: OBJECTIVE
  The purpose of this study was to investigate, in a model, the interaction phenomena of platform switching on the trans-cortical section of bone adjacent to an endosseous dental implant.
  
  
  METHODS
  A 2-dimensional finite element model was fabricated to analyze the bone-implant interactions under masticatory forces. Two abutment diameters, 4.5 mm representing platform switching and 5 mm representing a standard platform, were used in conjunction with a 5-mm diameter fixture. A 100-N static force was applied vertically (90 degrees) and obliquely (15 degrees) to the abutments. All models were obtained using a reverse engineering process with values obtained from other studies to create a hypothetical implant system that demonstrates basic implant features.
  
  
  RESULTS
  The standard platform model demonstrated a maximum crestal Von-Mises stress of 28 and 6.977 MPa under oblique and vertical load-ing, respectively. The platform switching model showed 27.43 and 6.502 MPa under oblique and vertical loading, respectively. This implies that a 10% reduction in abutment diameter results in a 2.04% and 6.81% decrease under oblique and vertical loading, respectively, in Von-Mises stress. The distribution pattern of forces was minimally altered between both abutment models, with a slightly more significant change in the vertical loading scenario.
  
  
  CONCLUSIONS
  Results from this study showed the reduction of abutment diameter (i.e., platform switching) resulted in a measurable but minimal effect on Von-Mises stress in the crestal region of cortical bone. However, future clinical trials in this area are warranted before any firm conclusion is drawn.
authors.affiliation: School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Schrotenboer
authors.forename: Yi-Pin
authors.initials: YP
authors.lastname: Tsao
authors.forename: Vipul
authors.initials: V
authors.lastname: Kinariwala
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology; D000539:Alveolar Process / Q000502:physiology*; D001732:Bite Force; D003198:Computer Simulation; D000044:Dental Abutments; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000379:methods; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D008334:Mandible; D008954:Models, Biological; D033081:Shear Strength
chemical_list: D015921:Dental Implants