title: Implementation of contact definitions calculated by FEA to describe the healing process of basal implants.
abstract: OBJECTIVE
  Bone structure around basal implants shows a dual healing mode: direct contact areas manifest primary osteonal remodeling, in the void osteotomy-induced spaces, the repair begins with woven bone formation. This woven bone is later converted into osteonal bone. The purpose of this study was to develop a model to accurately represent the interface between bone and basal implant throughout the healing process. The model was applied to the biological scenario of changing load distribution in a basal implant system over time.
  
  
  METHODS
  Computations were made through finite element analysis using multiple models with changing boneimplant contact definitions which reflected the dynamic nature of the interface throughout the bony healing process. Five stages of bony healing were calculated taking into account the changes in mineral content of bone in the vicinity of the load transmitting implant surfaces.
  
  
  RESULTS
  As the bony integration of basal implants proceeds during healing, peak stresses within the metal structure shift geographically. While bony repair may still weaken osteonal bone, woven bone has already matured. This leads to changes in the load distribution between and within the direct contact areas, and bone areas which make later contact with implant.
  
  
  CONCLUSIONS
  This study shows that basal implants undergo an intrinsic shift of maximum stress regions during osseointegration. Fatigue testing methods in the case of basal implants must therefore take into account this gradual shift from early healing phase until full osseointegration is achieved.
authors.affiliation: Gommiswald Dental Clinic, Dorfplatz 11, 8737 Gommiswald/SG, Switzerland. dr.ihde@bluewin.ch
authors.forename: Stefan
authors.initials: S
authors.lastname: Ihde
authors.forename: Tomas
authors.initials: T
authors.lastname: Goldmann
authors.forename: Lucie
authors.initials: L
authors.lastname: Himmlova
authors.forename: Zoran
authors.initials: Z
authors.lastname: Aleksic
authors.forename: Jiri
authors.initials: J
authors.lastname: Kuzelka
mesh_terms: D003198:Computer Simulation; D003758:Dental Implantation, Endosseous; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008334:Mandible; D016348:Osseointegration