Stress distribution in Class I composite restorations with polyethylene fiber wallpapering under different occlusal loads: A three-dimensional finite element analysis

Context: Class I composite restorations in posterior teeth often fail due to polymerization shrinkage and uneven load distribution. Aims: This study aimed to observe the stress distribution in polyethylene fiber-reinforced composite resin restorations placed using the wallpapering technique. Settings and Design: Finite element analysis. Materials and Methods: A 3D dental model of a maxillary premolar was developed using CBCT and then imported for reconstruction and geometry refinement. Four groups were then created: intact tooth, Class I cavity, conventional composite restoration, and wallpapering fiber-reinforced composite restoration. Simulations were performed using ANSYS 2025 R1 with vertical loads of 300N and 738N on the central fossa. Statistical Analysis Used: Von Mises stress distribution was analyzed across three layers using two-way ANOVA (α =0.05). Results: Load magnitude ( F = 4289.44, P < 0.001) and restoration type ( F = 123.11, P < 0.001) significantly influenced stress distribution. Fiber wallpapering reduced peak von Mises stress from 4391.4 MPa (cavity) to 1575.1 MPa (52.6% reduction, P < 0.001), approaching intact tooth values (2156.3 MPa). Stress distribution patterns showed broader low-stress zones and more uniform load transfer despite no statistical difference in mean stress compared to conventional composite ( P > 0.05). Conclusions: Wallpapering polyethylene fiber placement biomimetically redistributes stress with load-dependent effectiveness, offering the greatest potential benefit in high-load conditions rather than standard Class I restorations.