Physiology of dentinogenesis and pathophysiology of dentinogenesis imperfecta: how does it affect dentin structure and biomechanics?

Although the formation, structure, and biomechanical properties of dentin are well-studied, the impact of dentinogenesis imperfecta (DI) on dentin tissue structure and properties remains poorly understood. This perspective paper aims to summarize current knowledge on dentin and discuss the DI-related effects on dentin biological, structural and biomechanical properties. Macroscopically, DI is easily recognizable in clinics, characterized by a blue/gray appearance of the teeth and rapid pulp chamber obliteration after tooth eruption. Microscopically, the porous structure of healthy dentin is absent; tubules are scarce, and some areas are completely atubular. Clinically, the enamel of DI-affected teeth detaches quickly from the dentin, leading to rapid wear of the dentin under normal masticatory forces. The biomechanical properties of DI-affected dentin are poorly studied and challenging to compare with those of healthy dentin. Various factors, such as hydration, tissue heterogeneity, and the scale of analysis, significantly influence the measurement of these properties. An in-depth exploration of the micro- and nano-structure, as well as the biomechanical properties of dentin affected by DI, would provide a better understanding of the behavior of this diseased tissue in patients. This, in turn, would enable the adaptation of dental restoration treatments to meet the mechanical constraints specific to the oral environment. STATEMENT OF SIGNIFICANCE: This manuscript presents a comprehensive perspective on dentin as a biological material. We detail the dentinogenesis processes that govern healthy dentin formation and its microstructural development. We link dentin's functional biomechanics to its hierarchical organization. The work highlights how Dentinogenesis Imperfecta disrupts dentin structure at multiple scales, resulting in altered mechanical properties. Importantly, it draws direct connections between biological alterations and functional consequences, offering critical insights into structure-function relationships in mineralized tissues. This perspective bridges developmental biology, genetic diseases, and a biomaterials-based approach.