Titanium-Zirconia abutment-implant assemblies: Are they alternatives for single material implants?

To compare the biomechanical performance of titanium, zirconia, and titanium-zirconia hybrid abutment-implant assemblies using finite element analysis (FEA).

Four three-dimensional finite element models of implant-abutment-crown assemblies were developed using Solid Works 2022 SP3.1 and Abaqus 2022 (Dassault Systèmes), based on the abutment-implant systems: (1) Titanium abutment and implant - Ti-Ti, (2) Zirconia abutment and implant - ZrO₂-ZrO₂, (3) hybrid - titanium abutment with zirconia implant - Ti-ZrO₂, and (4) hybrid - zirconia abutment with titanium implant - ZrO₂-Ti. A cemented-retained zirconia crown and a 5-mm diameter abutment, with no inclination, were used in all models. The fit between the abutment and the implant was performed by a 9-mm length and 1-mm diameter titanium abutment screw. Volumetric finite elements with a linear tetrahedral shape (C3D4) and "tie" interactions represented 100 % of osteointegration. A distributed load of 200 N was applied to the crown, while the bone was fully constrained. For linear analysis, all materials were assumed to be linear, elastic, isotropic, and homogeneous. The FEA focused on evaluating the stress distribution within the implant, abutment, and surrounding tissues.

The hybrid zirconia-titanium assembly exhibited lower peak stress at the gingiva compared to the titanium-zirconia model and the full titanium or zirconia implant models. The hybrid titanium-zirconia and the full titanium assembly demonstrated the lowest peak stress in the bone, whereas the zirconia-titanium model and the full zirconia implant models exhibited higher stresses. The full titanium and the titanium-zirconia assemblies exhibited the highest stress concentration at the implant-abutment interface, highlighting potential areas for mechanical failure.

Finite element analysis indicates that the hybrid zirconia-titanium abutment-implant assembly offers a viable alternative to single-material implants. The hybrid configurations combine the advantages of both materials, promoting balanced stress distribution and favourable biomechanical performance. The findings suggests that titanium-zirconia hybrid implants may enhance implant longevity and success rates, making them a promising option for clinical applications.