Nanoscale pathways for human tooth decay – Central planar defect, organic-rich precipitate and high-angle grain boundary

Characterization of Enamel and Dentine about a White Spot Lesion: Mechanical Properties, Mineral Density, Microstructure and Molecular Composition

“…During caries development, the crystallites become partially demineralized generally at the cores and some interfaces as observed during transmission electron microscopic study [ 46 ], where the central dark line inside a crystallite represented a stacking fault resembling a dislocation and residual stresses were present about the core. This line possesses a higher concentration of Mg and Na [ 16 ] and crystallographic point defects (impurities, vacancies etc.) that would contribute to it being more soluble resulting in greater porosity.…”

“…Such diseased enamel usually presents a near intact surface layer of 10–100 µm thickness with a subsurface porous area called the body of the lesion. The pores are formed as a consequence of partial dissolution of carbonated hydroxyapatite crystallites due to etching caused by carbohydrate metabolizing cariogenic biofilm bacteria producing organic acids [ 16 ]. Due to the significant difference of the refractive indices of the medium inside the acid-created pores of the demineralization area, a whitish opaque appearance of these lesions can be observed.…”

Mineralization of dental tissues and caries lesions detailed with Raman microspectroscopic imaging

“…The stoichiometric imperfect crystals are common in the demineralization process. Precipitations with high amounts of carbonate content are associated with caries lesions 28,29 . Based on our mineral crystallinity results, these crystals of caries tissues were thicker than of dentin tissues but thinner than the crystals of enamel tissues (Table 2).…”

Estudio del Esmalte Dental Humano por Microscopía Electrónica

“…Recientemente se ha reportado un cambio de concentración en la región de la CDL ya que se presenta un mayor porcentaje de Mg 2+ y de Na + en el centro del cristal del esmalte. El ancho FWHM del perfil de concentración de Mg a través del CDL es de alrededor de 1 nm, lo cual concuerda con el ancho de la CDL (DeRocher et al, 2020;Yun et al, 2020). Existen varias hipótesis sobre la estructura y composición química de la CDL y sobre el papel que juega en la estructura del esmalte dental humano.…”

“…La diferencia en concentración química indica que la sobreposición de los átomos de la celda de HAP produce la existencia de esfuerzos y deformaciones. Se supone que esta zona de deformaciones es rica en Mg y en Na (DeRocher et al, 2020;Yun et al, 2020), lo cual explica bien con la disolución preferencial en medios ácidos del cristal del esmalte. Para la interpretación de la estructura de la CDL, se ha sugerido que ésta tiene su origen durante la amelogénesis, cuando el cristal del esmalte dental comienza a crecer desde este sitio central, y la cual adsorbe iones de impurezas de todo el cristal para que se concentren ahí (DeRocher et al, 2020;Yun et al, 2020).…”