Fracture Resistance of Endodontically Treated Teeth Restored with Different Fiber Post Systems Under Cyclic Loading: An In Vitro Study

Objectives: The healing process of endodontically treated teeth requires special attention due to lost tooth structure. The collective use of fiber post systems for reinforcement in dentistry requires further evaluation regarding their response to repetitive load tests. This research investigates the fracture resistance of teeth with endodontic treatment that received various fiber post systems when subject to cyclic loading conditions. Methods: A total of sixty human premolars received endodontic therapy after which researchers divided the specimens randomly into three groups (n = 20) for testing different fiber post systems. The studies used Group I (Glass fiber posts), Group II (Carbon fiber posts), and Group III (Quartz fiber posts). The researchers standardized the post space to which they used dual-cure resin cement for the posts' placement. Full-coverage crowns received the composite resin core buildup treatment. The research specimens faced 500,000 cycles of 100 N tensile force under conditions of 5°C–55°C in a thermocycling chamber. A universal testing machine operated at a crosshead speed of 1 mm/min until failure to evaluate the specimen fracture resistance after loading. Results: One-way ANOVA statistical analysis demonstrated significant variation across groups at a 0.003 p-value while post hoc Tukey’s test established a 0.001 p-value difference between carbon and quartz fiber post groups (95% confidence interval: -160 to -60). The comparison between glass and quartz fiber posts yielded results without a significant statistical variation (p = 0.08; 95% CI: -110 to 10). Conclusion: Quartz fiber posts displayed the best fracture resistance under functional simulation conditions which suggests they should be considered as the top reinforcement option for endodontically treated teeth in clinical applications.