title: Effect of Platform Shift/Switch on Crestal Bone Levels and Mucosal Profile Following Flapless Surgery and Crestal/Subcrestal Implant Placement.
abstract: BACKGROUND
  Crestal remodeling/bone loss appears a common sequel to dental implant placement. Several hypotheses and clinical strategies have been advanced to explain and avert crestal remodeling; however, causative mechanisms remain unclear and the efficacy of clinical protocol uncertain.
  
  
  OBJECTIVE
  The objective of the present study was to provide a histologic record of crestal versus subcrestal implant placement on crestal remodeling and mucosal profile comparing platform shift/switch and standard abutments following flapless implant surgery using a dog model.
  
  
  METHODS
  Four dental implants each were placed into the left and right edentulated posterior mandibles in five adult male hound-Labrador mongrel dogs using a flapless approach including crestal versus subcrestal placement and using platform shift versus standard abutments. Block biopsies were collected for histological/histometric analysis following an 8-week healing interval.
  
  
  RESULTS
  Both crestal and subcrestal implant installation resulted in significant crestal remodeling and bone loss, in particular at buccal sites, without significant differences between platform shift/switch and standard abutments. Implants installed subcrestally exhibited a significantly taller mucosal profile over crestal-level implants without significant differences between platform shift/switch and standard abutments; the epithelial attachment at all times arrested on the abutment surface.
  
  
  CONCLUSIONS
  Comparing platform shift/switch versus standard abutments using a minimally invasive flapless approach including crestal or subcrestal implant placement, the platform shift/switch abutments offer no selective advantage over standard abutments.
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.
authors.forename: Jaebum
authors.initials: J
authors.lastname: Lee
authors.affiliation: Section of Periodontology, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Fiorini
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.|Clinica Dental Gamborena, San Sebastian, Spain.
authors.forename: Inãki
authors.initials: I
authors.lastname: Gamborena
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Wenzel
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.|Peter Schüpbach GmbH, Horgen, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Schüpbach
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.
authors.forename: Ulf M E
authors.initials: UM
authors.lastname: Wikesjö
authors.affiliation: Laboratory for Applied Periodontal and Craniofacial Regeneration, Georgia Regents University, Augusta, GA, USA.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Susin
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D000539:Alveolar Process / Q000473:pathology / Q000601:surgery*; D000818:Animals; D001706:Biopsy; D016723:Bone Remodeling; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods*; D004285:Dogs; D004846:Epithelial Attachment / Q000473:pathology; D008297:Male; D014945:Wound Healing
keywords: alveolar bone; animal models; crestal remodeling; crestal resorption; dental implants; platform shift; platform switch