Three-Dimensional Finite Element Analysis of Different Connector Designs for All-Ceramic Implant-Supported Fixed Dental Prostheses

Abstract

All-ceramic fixed dental prostheses (FDPs) tend to fracture at the connector regions due to high stress concentration at these areas influenced by their design. This study was performed as an adjunct to an existing clinical study to evaluate the influence of the different radii of curvature of gingival embrasure on the stress distribution of a three-unit all-ceramic implanted supported FDP. Three three-dimensional (3D) models were created by scanning two titanium dental implants, their suitable zirconia abutments, and a patient-retrieved dental prosthesis using a micro-CT scanner. The radius of curvature of the gingival embrasure for the distal connector of the FDP was altered to measure 0.25 mm, 0.50 mm, and 0.75 mm. A finite element analysis (FEA) software (ABAQUS) was used to evaluate the impact of different connector designs on the distribution of stresses. Maximum Principal Stress data was collected from the individual components (veneer, framework, and abutments). The radius of curvature of gingival embrasure had a significant influence on the stress distribution at the assessed components. The tensile peak stresses at all structures were highest in the 0.25 mm model, while the 0.50 mm and 0.75 mm models presented similar values and more uniform stress distribution.

Automated Remodelling of Connectors in Fixed Partial Dentures

“…As described in the introduction, Alberto et al [12] found the radius of the interdental gingival shape to have a significant influence on the stresses in the FPD, whereas the smallest radius led to the highest tensile stresses. The way the connector design is altered in this study is dominated by Equations ( 1) and ( 2) presented in Section 2.1.2.…”

“…Besides the in vitro studies mentioned above, finite element analysis (FEA) was used in the literature to investigate the effect of connector design on the stresses in FPDs, and many studies found the connector design to have a significant influence on the failure behaviour or on observed stresses [12][13][14][15]. Furthermore, Alberto et al [12] found the radius of the interdental gingival shape to have a significant influence on the stresses in FPDs, whereas the smallest radius led to the highest tensile stresses. Almasi et al performed an 2 of 13 FEA on 3-unit FPDs and concluded that increasing the connector cross-sectional area and using a wider shape (ellipse) strongly decreases failure probability [13].…”

Effect of Ferrule Design on Stress Distribution of Maxillary Incisor Rehabilitated with Ceramic Crown and PEEK Post–Core Material: A 3D Finite Element Analysis

“…Through computational calculations, FEA provides the estimation of the stress distribution within the various components of a complex structure, such as teeth restored with post-retained crowns. Another advantage of FEA over the tests that evaluate and collect data from physical specimens is that FEA has a non-destructive nature, which reduces testing costs and provides fast results, with the flexibility to evaluate several material and load conditions [20][21][22]. Therefore, FEA was the test selected to evaluate the stress distribution in the 3D models of the current study.…”