Stress Distribution Pattern in Implant-Assisted Removable Partial Denture (IARPD): A 3D Finite Element Analysis

Abstract Removable partial dentures (RPDs) held in place by clasps have become a favored option for treating patients with partial tooth loss. However, these dentures have their drawbacks, including the issue of frequent displacement, which can lead to patient dissatisfaction and decreased usage, especially in situations involving the back of the lower jaw. The study aimed to examine the stress distribution pattern in implant-assisted RPDs (IARPDs). A computed tomographic scan of data from an edentulous patient was used to simulate a finite element three-dimensional (3D) model of the edentulous mandible. Using 3D modeling software (solid edge software, Siemens PLM software, United States), threaded implants and abutments were duplicated, and a framework was created. A 200 N axial and nonaxial stress was applied unilaterally and bilaterally. Higher stress concentrations were observed under unilateral loading compared with bilateral loading for all attachment systems. Under bilateral loading, locator attachments demonstrated the lowest implant stress (8.00 MPa) and reduced stress transfer to the surrounding bone. Under unilateral loading, healing caps exhibited the lowest implant stress (23.8 MPa), whereas ball attachments generated the highest stress values (44.4 MPa). Bilateral ball attachments showed the lowest framework stress (5.91 MPa) and prosthesis deformation (0.018 mm). Bilateral implant-assisted configurations demonstrated more favorable stress distribution than unilateral loading conditions. Locator attachments were most effective in minimizing stress transfer to the implant and surrounding bone under bilateral loading. In unilateral scenarios, ball attachments exhibited comparatively lower stress concentrations. These findings may assist clinicians in selecting appropriate attachment systems; however, clinical validation is required before definitive recommendations can be made.