title: Impact of implant-abutment connection, positioning of the machined collar/microgap, and platform switching on crestal bone level changes. Camlog Foundation Consensus Report.
abstract: OBJECTIVE
  The aim of this consensus meeting was to assess the impact of implant-abutment connection, positioning of the machined collar/microgap, and platform switching on crestal bone level changes.
  
  
  METHODS
  Two comprehensive systematic reviews were prepared in advance of the meeting. Consensus statements, practical recommendations, and implications for future research were based on within group as well as plenary scrutinization and discussions of these systematic reviews.
  
  
  RESULTS
  Placing the smooth part of the implant below the alveolar crest may lead to bone loss. Despite a more pronounced bone remodeling, the subcrestal positioning of the microgap may help to retain the bony coverage of the rough surface. Crestal bone remodeling has been observed for either internal and external, or conical and butt-joint connections. There was a trend favoring the platform switching concept to prevent or minimize peri-implant marginal bone loss.
  
  
  CONCLUSIONS
  Future research should consider an uniform and comparable study design, either excluding or exactly documenting possible confounding factors.
authors.affiliation: Department of Oral Surgery, Heinrich Heine University, Düsseldorf, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwarz
authors.affiliation: Department of Periodontology, Lisbon Dental School, University of Lisbon, Lisbon, Portugal.
authors.forename: Gil
authors.initials: G
authors.lastname: Alcoforado
authors.affiliation: Department of Oral and Maxillofacial Surgery, Albert-Ludwigs University Freiburg, Freiburg, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Nelson
authors.affiliation: Camlog Foundation, Basel, Switzerland.
authors.forename: Alex
authors.initials: A
authors.lastname: Schaer
authors.affiliation: Department of Reconstructive Sciences, University of Connecticut School of Dental Medicine, Farmington, CT, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Taylor
authors.affiliation: Department of Prosthodontics, Munich Dental School, Munich, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Beuer
authors.affiliation: Charité Centre 3 for Dental, Oral and Maxillary Medicine, Department of Oral Medicine, Dental Radiology and Oral Surgery Charité - Medical University of Berlin / Charité, Berlin, Germany.
authors.forename: Frank Peter
authors.initials: FP
authors.lastname: Strietzel
mesh_terms: D016301:Alveolar Bone Loss / Q000517:prevention & control; D000539:Alveolar Process / Q000033:anatomy & histology*; D016723:Bone Remodeling / Q000502:physiology; D059605:Dental Implant-Abutment Design; D003758:Dental Implantation, Endosseous / Q000379:methods*; D018772:Dental Marginal Adaptation; D006801:Humans; D057873:Peri-Implantitis / Q000517:prevention & control
keywords: crestal bone level; titanium implants