Platform switching on wide-diameter external hex implants: a finite element analysis.
OBJECTIVE
The objective of this work was to use finite element analysis to compare the effect of forces coming to bear on abutments 4.1 or 5.0 mm in diameter connected to a 5.0 mm implant (i.e. with or without platform switching).


METHODS
A 3D CAD model of a 5 x 11.5 mm external hex implant was developed, complete with a connection screw and either of two abutments, one 4.1 and the other 5 mm in diameter, to assess the influence of two loading conditions, i.e. 200 N loaded either axially or off center on the top of the abutment.


CONCLUSIONS
In the symmetrically loaded models, greater stresses were transmitted to the bone in the area below the neck of the implant in the case of the wider-diameter abutment. When the narrower abutment was considered, the stress lines remained confined to the metal and were transferred to the bone in a more distal position. When the stresses in the bone where compared under non-symmetrical loading of the larger- and smaller-diameter abutments, the stresses reached lower values in the latter case. These findings indicate that platform switching (i.e. coupling a 4.1 mm abutment with a 5 mm implant) achieves a better, more even distribution of the peri-implant stresses deriving from simulated occlusal loads on the bone margins. Key words:Platform switching, finite element analysis, implant.
DDS, Clinical Assistant, Department of Oral Surgery, Padova University, Institute of Clinical Dentistry, Padova, Italy.
Stefano
S
Sivolella
DDS, Resident, Department of Oral Surgery, Padova University, Institute of Clinical Dentistry, Padova, Italy.
Riccardo
R
Guazzo
DDS, Associate Professor, Department of Periodontology, Padova University, Institute of Clinical Dentistry, Padova, Italy.
Eriberto
E
Bressan
MD, DDS, Professor and Chairman, Department of Oral Surgery, Padova University, Institute of Clinical Dentistry, Padova, Italy.
Mario
M
Berengo
DDS, Associate Professor, Department of Periodontology, Padova University, Institute of Clinical Dentistry, Padova, Italy.
Edoardo
E
Stellini