An Evaluation of New Designs in Implant-Abutment Connections: A Finite Element Method Assessment
Covani U., Ricci M., Tonelli P., Barone A.
Implant Dentistry Volume 22, Number 3 2013, pages 263-267
This interesting study carried out by the group of Prof. Covani compares, by some mechanical FEM (Finite Element Method) tests, the traditional Premium connection with the same connection virtually changed with purpose of investigation.
The hypothetical connections taken into account are:
• Hypothetical Premium implant with internal hexagon connection but without external collar;
• Hypothetical Premium implant with external hexagon connection;
These two virtual connections have been compared to the traditional Premium internal hexagon connection with overhanging collar for the prosthetic repositioning (COLLEX) coupled either with a Premium post and with a rotating Simple post, led by the collar and a cylindrical invitation but without hexagon. The results of the tests emphasize the added value of the Premium connection without the collar for the prosthetic support; in fact, the traditional Premium connection (COLLEX) has obtained the best results in particular in terms of strength of the screw, known to be the most critical element of any implant-screw–post group.
The contribution of the collar to the mechanical strength is substantial, so that the second best result found is related to the test on a Premium implant in connection with a Simple post, which, despite being without hexagon, shows significantly better values than the hypothetical connection with external hexagon or the internal hexagon one with no overhanging collar. This study therefore confirms the greater resistance to mechanical stress by the internal connection assisted by the presence of the external collar of prosthetic support, able to protect the tightening screw and, consequently, to limit the probability of its fracture.
