Enhancing Tensile Bond Strength of Glass Fiber Posts Using Chitosan as a Coupling Agent: A Novel Approach for Improved Dental Restorations

Objectives: This study was designed to assess the effectiveness of chitosan as a coupling agent for improving the tensile bond strength of fiber posts. Methods: A total of 91 single-rooted mandibular teeth were root canal-filled. Post spaces were created and categorized into seven groups: Group A (Control), Group B (Silane), Group C (Chitosan), Group D (37% Phosphoric acid + Silane), Group E (37% Phosphoric acid + Chitosan), Group F (10% Hydrogen Peroxide + Silane), and Group G (10% Hydrogen Peroxide + Chitosan). Posts were cemented and tensile bond strength was measured, while the morphological structure of the fiber posts was analyzed using Scanning Electron Microscopy. One-way (ANOVA) and Tukey’s multiple comparison tests were performed at a level of significance of 5%. The percentages of fracture patterns among the groups were compared. Results: 10% Hydrogen peroxide + Chitosan exhibited the significantly highest tensile bond strength (p < 0.001). Adhesive failures were more frequent in Groups A, B, C, and D, whereas cohesive failures within the resin cement were predominant in Groups E, F, and G. Conclusions: The protocol of using 10% hydrogen peroxide followed by a chitosan coupling agent significantly improved tensile bond strengths for glass fiber posts, which highlights the potential of using chitosan as a natural biopolymer and an alternative to synthetic coupling agents to develop more effective bonding strategies for dental restorations.