Lateral stress distribution analysis on hafnium metal bar for implant superstructure- A finite element analysis

The mechanical behavior of implant-supported prostheses is strongly influenced by the material properties of the bar framework, particularly under lateral masticatory loading. While titanium and cobalt-chromium are established materials, alternatives such as polyetheretherketone (PEEK) and hafnium may offer distinct biomechanical advantages. The aim of this study was to compare the lateral stress distribution in implant-supported prostheses fabricated with four different bar materials using finite element analysis.

ology: A three-dimensional finite element analysis (FEA) was conducted on a mandibular edentulous model with four endosseous implants arranged in an All-on-4 configuration. Four groups were evaluated based on bar material: titanium (Ti), cobalt-chromium (CoCr), polyetheretherketone (PEEK), and hafnium (Hf). A total of four simulation models were created, each subjected to a 100 N anterior and 300 N posterior lateral load. Von Mises stresses were analyzed in the bar, abutments, screws, and peri-implant bone.

PEEK recorded the lowest stress in the bar (∼25 MPa) and peri-implant bone but induced elevated stresses in the abutment (348 MPa) and screw (288 MPa). CoCr showed the highest stress within the bar (∼114 MPa) with lower values in other components. Titanium and hafnium presented a balanced stress profile, with no region exceeding 300 MPa. Hafnium closely mirrored titanium's biomechanical response, demonstrating efficient load distribution without critical stress concentrations.

Bar material significantly affects lateral stress distribution in implant-supported prostheses. Hafnium displayed biomechanical behavior comparable to titanium, indicating its promise as a potential alternative framework material. Further in vitro and clinical validation is warranted.