title: Immediate versus conventional loading of implant-supported maxillary overdentures: a finite element stress analysis.
abstract: OBJECTIVE
  To compare biomechanical outcomes of immediately and conventionally loaded bar-retained implant-supported maxillary overdentures using finite element stress analysis.
  
  
  METHODS
  Finite element models were created to replicate the spatial positioning of four 4.1 × 12-mm implants in the completely edentulous maxillae of four cadavers to support bar-retained overdentures with 7-mm distal extension cantilevers. To simulate the bone-implant interface of immediately loaded implants, a contact situation was defined at the interface; conventional loading was simulated by "bonding" the implants to the surrounding bone. The prostheses were loaded with 100 N in the projected molar regions bilaterally, and strain magnitudes were measured at the buccal aspect of bone.
  
  
  RESULTS
  The amplitude of axial and lateral strains, the overall strain magnitudes, and the strain magnitudes around anterior and posterior implants in the immediate loading group were comparable to those seen in the conventional loading group, suggesting that the loading regimens created similar stress/strain fields (P > .05).
  
  
  CONCLUSIONS
  Conventional and immediate loading of maxillary implants supporting bar-retained overdentures resulted in similar bone strains.
authors.affiliation: Department of Prosthodontics, Faculty of dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Kivanc
authors.initials: K
authors.lastname: Akca
authors.forename: Atilim
authors.initials: A
authors.lastname: Eser
authors.forename: Steven
authors.initials: S
authors.lastname: Eckert
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Cavusoglu
authors.forename: Murat Cavit
authors.initials: MC
authors.lastname: Cehreli
mesh_terms: D001641:Bicuspid; D001696:Biomechanical Phenomena; D001732:Bite Force; D002102:Cadaver; D017076:Computer-Aided Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D003828:Denture, Overlay; D020342:Finite Element Analysis; D006801:Humans; D057893:Immediate Dental Implant Loading; D007180:Incisor; D007575:Jaw, Edentulous / Q000503:physiopathology / Q000534:rehabilitation*; D008437:Maxilla; D013314:Stress, Mechanical