Abstract
Human dentin is known for its hierarchical structure through long-term evolution. Dental caries, embodied by dentin demineralization, is ascribed to a different reaction between peritubular dentin (PTD) and intertubular dentin (ITD) to acid dissolution. This study sheds light on the adverse effect of acid on dentin in terms of degradation of its fracture toughness (FT) due to the acid dissolution-induced erosion of PTD. A scanning electronic microscope (SEM) is utilised to visualise the difference between normal and acid-treated dentin subjected to the same loading method in terms of crack propagation performance. 3D simulative representative volume elements (RVEs) are developed to analyse the effect of PTD missing on the performance of dentin fracture resistance (FR). The results indicate PTD plays a significant role in enhancing dentin FR capability and thus reveals the importance of structural integrity for dentin.