Finite element analysis of implant-assisted removable partial dentures: Framework design considerations

Area of Science:

• Biomaterials Engineering
• Dental Prosthetics
• Finite Element Analysis

Background:

• Connecting acrylic resin bases to metal frameworks and implants can influence prosthesis rotational displacement under load.
• Understanding these biomechanical interactions is crucial for stable implant-assisted removable partial dentures.

Purpose of the Study:

• To analyze the impact of connecting a denture base metal framework to an implant.
• To investigate methods for decreasing rotational movement in implant-assisted removable partial dentures.

Main Methods:

• Modeled mesial and distal occlusal rest direct retainers with modified denture base metal frameworks.
• Utilized finite element analysis (FEA) to determine stress and deformation patterns.
• Compared prosthesis structural behavior between the mesial and distal designs.

Main Results:

• Maximum von Mises stress on the metal framework was 923 MPa (mesial) and 1478 MPa (distal).
• Maximum von Mises stress on the acrylic resin base was 17 MPa (mesial) and 29 MPa (distal).
• The distal occlusal rest design exhibited significantly lower stress and deformation.

Conclusions:

• The distal occlusal rest direct retainer demonstrates greater stiffness, with approximately 66% less deformation than the mesial design.
• A modified denture base framework incorporating an I-bar and distal occlusal rest enhances support for the acrylic resin structure.