title: Biomechanical effects of platform switching in two different implant systems: a three-dimensional finite element analysis.
abstract: OBJECTIVE
  The purpose of this study was to determine the influence of platform switching on stress distribution of two different implant systems using three-dimensional (3D) finite element models.
  
  
  METHODS
  Six 3D finite element models were created to replicate two different implant systems with peri-implant bone tissue, in which six different implant-abutment configurations were represented: model XiVE-a: 3.8-mm-diameter implant and 3.8-mm-diameter abutment; model XiVE-b (platform-switching model): 4.5-mm-diameter implant and 3.8-mm-diameter abutment; model XiVE-c: 4.5-mm-diameter implant and 4.5-mm-diameter abutment; model 3i-a: 4.0-mm-diameter implant and 4.1-mm-diameter abutment; model 3i-b (platform-switching model): 5.0-mm-diameter implant and 4.1-mm-diameter abutment; model 3i-c: 5.0-mm-diameter implant and 5.0-mm-diameter abutment. vertical and oblique loads of 100 were applied to all models.
  
  
  RESULTS
  While the pattern of stress distribution was similar for both loading situations, oblique loading resulted in higher intensity and greater distribution of stress than axial loading in both cortical bone and implant-abutment- interface. Stress distribution at peri-implant bone was almost identical with similar magnitudes for all six models. In both implant systems, platform-switching models demonstrated lower maximum von Mises stress in cortical bone than conventional models. However, in both implant systems and under both loading situations, platform-switching models showed higher stresses at the implant-abutment interface than conventional models.
  
  
  CONCLUSIONS
  In both implant systems, platform switching design reduced the stress concentration in the crestal bone and shifted it towards the area of implant-abutment interface.
authors.affiliation: Assistant Professor, Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Dental Research Center, Research Institute of Dental Sciences of Shahid Beheshti, University of Medical Sciences, Tehran, Iran.
authors.forename: Mahasti
authors.initials: M
authors.lastname: Sahabi
authors.affiliation: Periodontist, Department of Periodontology, School of Dentistry, Isfahan University of Medical Science, Isfahan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Adibrad
authors.affiliation: Dental Research Center, Research Institute of Dental Sciences of Shahid Beheshti, University of Medical Sciences, Tehran, Iran ; MSc, Ph.D Student, Mechanics of Agricultural Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Fatemeh Sadat
authors.initials: FS
authors.lastname: Mirhashemi
authors.affiliation: Assistant Professor, Department of Prosthodontist, Tehran University of Medical Sciences, International Campus, Dental School, Tehran, Iran.
authors.forename: Sareh
authors.initials: S
authors.lastname: Habibzadeh
keywords: Abutment Design; Alveolar Bone Loss; Dental Implants; Finite Element Analysis