Comparison of Enamel, Dentin, and the Dentin–Enamel Junction in Horse, Dog, Wild Boar, and Macaque Using Confocal Raman Microscopy

The dentin–enamel junction (DEJ) is an interface that couples highly mineralized enamel to collagen‐rich dentin and plays a key role in crack deflection and load transfer. However, how its chemo‐structural organization varies among mammals with contrasting diets remains poorly documented. This study compared the DEJ of horse, dog, wild boar, and macaque teeth using confocal Raman microscopy. Sagittal sections crossing the tooth were mapped across the DEJ region. Mean spectra and Raman maps of mineral (ν₁, ν₂, ν₃, and ν₄ PO₄ 3− , A‐ and B‐type CO₃ 2− ) and organic (amide I/III, CH stretching) bands were extracted, and principal component analysis (PCA) was performed on normalized peak intensities to assess interspecific discrimination. Dog and macaque dentin displayed relatively higher organic bands than horse and wild boar, suggesting a more collagen‐rich matrix. Raman maps of the ν₁ PO₄ 3− and CH bands revealed species‐specific DEJ widths and mineralization profiles, as well as differences in the abundance and morphology of secondary structures: scallop, tubules, spindles, and presence of hypermineralized bands. PCA robustly discriminated species on the basis of both enamel and dentin peaks spectra. These findings demonstrate that confocal Raman microscopy can resolve species‐specific chemo‐structural signatures of the dentin and enamel at the DEJ, providing a framework for future correlations with diet, occlusal loading, and local mechanical stresses.