Comparing different bar materials for mandibular implant-supported overdenture: Finite-element analysis

Area of Science:

• Biomaterials Science
• Dental Implantology
• Biomechanics

Background:

• Mandibular implant-supported overdentures (OD) require careful material selection for bar components to ensure longevity and minimize stress on the bone.
• Understanding the mechanical behavior of different bar materials under functional loads is crucial for optimizing OD design.

Purpose of the Study:

• To optimize the selection of bar material for mandibular implant-supported overdentures (OD) by evaluating stress distribution and deformation.
• To compare the mechanical performance of different bar materials, specifically polyether ether ketone (PEEK) and stainless steel, under simulated occlusal forces.

Main Methods:

• A three-dimensional finite-element model of an implant-supported overdenture was created using engineering computer-aided design (CAD) software.
• The model was analyzed within the ANSYS environment, applying a 200 N vertical force to the left second premolar area to simulate functional loading.
• Von Mises stress and total deformation were evaluated for different bar materials, including PEEK and stainless steel.

Main Results:

• The polyether ether ketone (PEEK) bar exhibited the lowest Von Mises stress on the overdenture (OD) and the maximum deformation under the tested conditions.
• Conversely, the stainless steel bar resulted in the maximum OD total deformation, indicating higher stress concentration or less flexibility.
• Mandibular cortical and spongy bone were found to be insensitive to the type of bar material used.

Conclusions:

• Increasing the stiffness of the bar material leads to higher Von Mises stresses within the bar itself and reduced overall deformation, characteristic of an overconstrained system.
• Polyether ether ketone (PEEK) emerges as a favorable material for bar fabrication in mandibular implant-supported overdentures due to its stress-minimizing properties.
• Material selection significantly impacts the mechanical behavior of the bar component in implant prosthetics, influencing stress distribution and deformation.