Biomechanics of Dental Implant Abutment Constructs

Biomechanics of Dental Implant Abutment Constructs
R. APONTE-WESSON, G.S. KOHLI, J.T. WILLIS, W.R. LACEFIELD, and J.E. LEMONS, University of Alabama, Birmingham, USA
2004
IADR
Identifying the functional aspects of dental implant systems is essential for the long-term success of restorations. The occurrence of screw loosening and screw fracture has increased interest in different implant system abutment. Objective: The effect of a cantilever force applied to the implant-abutment on different types of commercially available dental implants was studied to determine the influence of joint design and material on the structural deformability of the systems. Methods: Four different types of endosteal-designs were tested including an internal connection: (Replace SelectÇ—¢ with TorqTightÇ—¢ screw, Crystal-Seal¨? with collet locking connection), and external hex: (Steri-Oss¨? with TorqTightÇ—¢ and 3i¨? with gold plated screw). 32 donated specimens were tested in four test groups of (8 specimens each). The samples and their respective screw-retained interlocking single tooth abutments were grouped depending on the type connection and tested in a bending mode (shear/cantilever forces) with load applied perpendicular to the abutment using an Instron universal test machine. Samples fixed and aligned were loaded at a crosshead speed of 0.125 cm/second and photographs taken at 2X in different load/time intervals to note the various stages of joint opening. Each design was subjected to increasing magnitudes of force, while observing and recording abutment-to-implant joint opening. Groups were analyzed using ANOVA and Fisher's PLSD test. Significance was set to alpha=0.05. Results: The mean in Newtons force (N¨±SD) required to open the implant-abutment joint was recorded by implant systems as follows: Steri-Oss¨? 105.4(¨±10.2), Replace SelectÇ—¢ 130.3(¨±11.1), Crystal-Seal¨? 236.2(¨±7.5) and 3i¨? 408.3(¨±7.5). All groups were significantly different (p<0.01). Conclusions: The outcome of this study showed a rank ordering by implant type with significant differences between forces required to produce implant to abutment connection joint opening among implant systems tested.