title: Influence of implant geometry on primary insertion stability and simulated peri-implant bone loss: an in vitro study using resonance frequency analysis and damping capacity assessment.
abstract: OBJECTIVE
  To investigate the influence of implant geometry on primary stability and on peri-implant bone loss in an in vitro model using the Periotest and Osstell devices.
  
  
  METHODS
  Screw-type implants of various diameters and lengths were inserted into bovine bone blocks of different densities, and the primary insertion stability was recorded. To study the influence of implant geometry on implant stability with different levels of peri-implant bone loss, implants were inserted into acrylic resin blocks to mimic osseointegration, and different amounts of the peri-implant acrylic resin were removed. Measurements with both devices at each millimeter step yielded the threshold for the least detectable attachment loss.
  
  
  RESULTS
  The predominant factors influencing implant stability were bone quality and attachment loss. Implant type and length exerted some influence on implant stability values, while variations in implant diameter produced only minor alterations in the measurements. In simulations of peri-implant attachment loss, implant stability decreased more dramatically for the shorter and narrower implants. The inclusion of more variables in the analyses resulted in less focused measurements.
  
  
  CONCLUSIONS
  The results of this study clearly show that the outcome of implant stability assessment depends on environmental factors such as bone quality and implant geometry. While the authors do not recommend the use of the Periotest or Osstell devices for a comparison of the stability of two individual implants, both should be useful to monitor the state of an individual implant over time.
authors.affiliation: Department of Prosthodontics and Medical Material Sciences, Faculty of Medicine, University Hospital, Eberhard-Karls-University of Tübingen, Germany. stefan.lachmann@med.unituebingen.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Lachmann
authors.forename: Johannes Yves
authors.initials: JY
authors.lastname: Laval
authors.forename: Detlef
authors.initials: D
authors.lastname: Axmann
authors.forename: Heiner
authors.initials: H
authors.lastname: Weber
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D016301:Alveolar Bone Loss / Q000209:etiology*; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000502:physiology; D002417:Cattle; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D008422:Materials Testing; D008953:Models, Anatomic; D016348:Osseointegration / Q000502:physiology; D012272:Ribs / Q000601:surgery; D013499:Surface Properties; D014732:Vibration
chemical_list: D000180:Acrylic Resins; D015921:Dental Implants; D003764:Dental Materials