Finite Element Analysis at the Implant/Bone Interface for One-piece vs. Multi-unit Implant Systems

Finite Element Analysis at the Implant/Bone Interface for One-piece vs. Multi-unit Implant Systems
28 June 2003
R.-F. WANG1, B.J. KANG2, and B.R. LANG1, 1 University of Michigan, Ann Arbor, USA, 2 Hoff & Associates, Ann Arbor, MI, USA
IADR
Objective: The recent introduction of implant systems that combine the implant and the abutment as one unit has prompted the question of whether or not these new systems result in different stresses at the bone to implant interface when compared with the multi-unit implant systems. This objective of this study was to measure the stress between the implant and the bone at specific location for a one-piece implant compared to a multi-unit implant system when subjected to an off-axis vertical force using finite element analysis
Methods: The Br?ïnemark Mark III implant, CeraOne abutment and the Unigrip screw were model for finite element analysis using HyperMesh¨? software. Similarly, the assembled implant structure was modeled as a one-piece unit. A finite element analysis was performed on both models subjected to a vertical off-axis load of 300 Newtons using ABAQUS¨? program.
Results: The stress measured within the cortical bone adjacent to the uppermost threads of both implant systems demonstrated the highest stress values. Stress measured for the one-piece implant was twice that of the multi-unit implant complex.
Conclusion: The one-piece implant unit demonstrated a greater stress at the bone to implant interface than the multi-unit implant system. The multi-unit implant system demonstrated a stress distribution pattern that was dramatically different than the one-piece implant when subjected to a vertical off-axis load.