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

Abstract

<h4>Background</h4>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.<h4>Method</h4>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.<h4>Results</h4>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.<h4>Conclusion</h4>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.