Fracture resistance of endodontically treated teeth restored with polyetheretherketone (PEEK) versus glass fiber posts: A comparative in vitro analysis

Aim: The aim of this study was to evaluate the fracture resistance and failure mode of three-dimensional (3D)-printed Polyetheretherketone (PEEK) posts and Glass Fiber Posts in endodontically treated teeth. Methods: Forty single-rooted mandibular premolars were decoronated 2 mm above the cementoenamel junction. The teeth were endodontically treated, post space prepared, and embedded into acrylic molds with polyvinyl siloxane to simulate the periodontal ligament. The samples were divided into two groups ( n = 20): Group 1 – 3D-printed PEEK posts and Group 2 – Glass Fiber Posts. They were cemented using self-adhesive resin cement. Specimens were subjected to fracture load testing using a universal testing machine until failure. Fracture modes were analyzed under a stereomicroscope. Statistical analysis was carried out using the independent t -test and Fisher’s exact test, with P ≤ 0.05 considered statistically significant. Results: The mean fracture resistance of the Glass Fiber Posts (685.51 ± 143.31 N) was significantly greater than PEEK (538.13 ± 97.66 N) ( P = 0.001). Fracture mode analysis revealed that 85% of PEEK posts recorded favorable fractures, while 80% of Glass Fiber Posts exhibited nonfavorable/catastrophic fractures ( P = 0.000). Conclusion: Glass Fiber Posts showed superior strength and stability, while PEEK posts effectively absorbed stress, reducing catastrophic fractures. PEEK may serve as a suitable alternative when preservation of tooth structure and fracture prevention is essential.