A parametrical finite element analysis for functionally graded material overlay restoration.

Bonded ceramic restorations often fail due to stress concentration at the prosthesis base. Prior research has shown that stress distribution is a critical factor in dental restoration longevity. However, the exact mechanisms of stress propagation in multilayered systems remain unclear. No prior work had resolved how functionally graded materials (FGMs) might improve stress dissipation in dental overlays. Existing studies focus on single-layer ceramics or uniform composites. This gap motivated an investigation into how FGMs could reduce stress peaks in dental prostheses. The need arises from limitations in current restoration designs that cannot adapt to mechanical loads effectively. That uncertainty drove the development of a finite element model to simulate FGM performance in dental overlays.

The aim of this paper is to optimize a multilayer FGM for dental overlays using finite element analysis. The specific problem is the high stress concentration observed in traditional ceramic restorations. The motivation stems from the need to improve mechanical performance in dental prostheses. The study seeks to determine how varying layer numbers and thicknesses affects stress distribution. It also investigates how Young’s modulus gradients influence mechanical behavior. The goal is to identify an optimal FGM configuration for clinical use. This approach could lead to more durable dental restorations. The study focuses on a 1.5-mm thick prosthesis with realistic geometry.

The study uses finite element analysis to evaluate FGM configurations in dental overlays. A factorial design approach was applied to assess multiple variables systematically. Layer numbers and thicknesses were varied within ceramic shaping constraints. Young’s modulus was adjusted to match dental tissue ranges. The analyses were conducted on a 3D model of a restored tooth. Realistic geometry was used to ensure clinical relevance. Mechanical stress distribution was simulated under occlusal loads. The optimal configuration was validated through proof-of-concept modeling.

The optimal FGM configuration consisted of five layers, each 0.2 mm thick. Young’s modulus varied linearly from 30 to 70 GPa across these layers. This setup reduced stress concentration at the prosthesis base. The 1.5-mm thick prosthesis showed improved mechanical performance. Stress peaks were lower than in single-layer ceramic models. The linear modulus gradient provided better stress dissipation. The 3D model confirmed the FGM’s effectiveness in reducing stress. These findings suggest a promising approach for dental restoration design.

The study suggests that FGMs can reduce stress concentration in dental overlays. The five-layer configuration with a linear modulus gradient appears most effective. This finding aligns with the authors' hypothesis about stress dissipation. The model supports the potential of FGMs in improving restoration durability. The results were validated through a 3D proof-of-concept simulation. No prior work had resolved the optimal FGM configuration for dental overlays. The authors propose that this design could enhance clinical outcomes. Further research may explore additional FGM configurations.