Investigating simultaneous mineralization across layers during tooth development using atomic force microscopy and Raman spectroscopy

Tooth development is a complex multi-step biochemical process characterized by the sequential formation and maturation of dental tissues, with biomineralization playing a central role in the production of mineralized tissues essential for various biological functions. This study focuses on the later stages of tooth development, marked by intense biomineralization, during which enamel and dentin undergo crucial structural transformations necessary to fulfill the mechanical functions of the tooth. Atomic force microscopy (AFM) nanomechanical testing provided insights into the microstructures and mechanical properties of enamel and dentin during both the advanced bell stage and post-eruptive stage. Additionally, Raman spectroscopy measurements revealed variations in the biochemical properties from advanced bell stage to post-eruptive stage. AFM-based micro-rheology results demonstrated that the dental papilla extracellular matrix exhibits spatially heterogeneous viscoelastic responses to dynamic mechanical stimuli, suggesting potential region-specific roles in mechanotransduction during tooth development. These findings highlight the spatial heterogeneity of microstructural, mechanical and biochemical properties that emerge during the late stages of tooth formation.