Stress distribution in titanium and zirconia implants with full-arch prostheses: a finite element analysis

The stress distribution and mechanical properties of materials used in dental implants are critically important for implant success and long-term stability. The aim of this study was to evaluate the stress distribution on implant, prosthetic system, and peri-implant tissues when titanium and zirconia implants are used with different framework materials using three-dimensional finite element analysis (FEA).

A three-dimensional edentulous maxilla model was reconstructed from computed tomography data, and twelve finite element models were subsequently developed based on this anatomy to represent different implant and framework configurations. Within the scope of the study, titanium and zirconia implants were modeled in combination with cantilevered and noncantilevered prosthesis types and Co-Cr, PEKK, and zirconium framework materials. An oblique static load of 200 N was applied at a 45° angle in the palato-buccal direction to the central fossa of the first molar on the models. The Von Mises and principal stress distributions in the implant, abutment, screw, framework, and peri-implant bone were examined.

The highest Von Mises value was recorded in the cantilevered PEKK framework zirconia implant model (378.388 MPa). Compared with the Co-Cr and zirconium framework, the PEKK framework resulted in higher Von Mises stresses and greater prosthesis displacement. The presence of a cantilever increased stress levels in all framework materials, and stress concentrations were observed particularly in posterior abutments and peri-implant bone. Furthermore, stress values in trabecular bone were recorded above the physiological threshold level in the cantilevered PEKK framework models.

Although zirconia implants exhibited greater stress than titanium implants, they remained within safe limits. Rigid framework materials and cantilever-free designs provide more balanced biomechanical results.