Stress behavior of an anterior single implant restored with high-performance polymer abutments under immediate and delayed loading: A 3D FEA study.

Purpose: To evaluate the stress generated on peripheral bone, implant, and prosthetic components while using polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) hybrid abutments in two different loading situations with nonlinear 3D finite element analysis.

Materials And Methods: Standard tessellation language (STL) files of original components were used for the in-silico modeling of implant, standard titanium abutment, and hybrid abutments (PEEK and PEKK). The implant was placed in the bone block to imitate immediate loading, in which a friction coefficient of 0.3 was set between the bone and the implant interface, or delayed loading, where the bone-implant interface was assumed to be perfect. In all models, both a horizontal force (25.5 N) and a 30-degree oblique force (178 N) were applied to the long axis of the implant to the palatal surface of the restoration. The stress distribution was evaluated.

Results: While more stress was observed in the prosthetic structures in the PEEK and PEKK models, the stresses on the implant and bone were similar in all models, regardless of the loading situation. Under immediate loading, PEEK hybrid abutments caused excessive stress accumulation on the titanium base abutment.

Conclusions: Even though abutment type did not affect the stresses on peripheral bone, PEEK and PEKK abutments generated greater stresses on the implant and the standard titanium abutment accumulated higher stresses. Oblique forces mostly generated greater stress than horizontal forces. Oblique forces on an immediately loaded implant led to stresses higher than the yield strength of a titanium implant when restored with PEEK hybrid abutment.