2024-06-07 マックス・プランク研究所
マックス・プランク固体研究所の研究者たちは、最新の画像技術を用いて、ビーバーやヌートリアなどの齧歯類の歯の構造をナノメートルスケールで解析し、外側のエナメル質に鉄を含む物質が存在することを発見しました。この物質は、齧歯類の歯が非常に強靭である理由とされています。
◆研究によると、この鉄を含む層はエナメル質の体積のわずか2%以下ですが、機械的特性や酸への耐性に決定的な役割を果たします。これにより、齧歯類の歯が自ら研ぎ澄まされる機能を持ち続けるのです。
◆この発見は、人間の歯科治療にも新しい素材の開発に役立つ可能性があります。鉄を含む新しい層は歯の色を変えずにエナメル質の特性を向上させるため、将来的には歯の修復材や歯科製品に応用できるかもしれません。
<関連情報>
げっ歯類の歯のエナメル質における独創的な構造と色調生成 Ingenious Architecture and Coloration Generation in Enamel of Rodent Teeth
Vesna Srot, Sophia Houari, Gregor Kapun, Birgit Bussmann, Felicitas Predel, Boštjan Pokorny, Elena Bužan, Ute Salzberger, Bernhard Fenk, Marion Kelsch, and Peter A. van Aken
ACS Nano Published:April 17, 2024
DOI:https://doi.org/10.1021/acsnano.4c00578
Abstract
Teeth exemplify architectures comprising an interplay of inorganic and organic constituents, resulting in sophisticated natural composites. Rodents (Rodentia) showcase extraordinary adaptations, with their continuously growing incisors surpassing human teeth in functional and structural optimizations. In this study, employing state-of-the-art direct atomic-scale imaging and nanoscale spectroscopies, we present compelling evidence that the release of material from ameloblasts and the subsequent formation of iron-rich enamel and surface layers in the constantly growing incisors of rodents are complex orchestrated processes, intricately regulated and independent of environmental factors. The synergistic fusion of three-dimensional tomography and imaging techniques of etched rodent́s enamel unveils a direct correlation between the presence of pockets infused with ferrihydrite-like material and the acid resistant properties exhibited by the iron-rich enamel, fortifying it as an efficient protective shield. Moreover, observations using optical microscopy shed light on the role of iron-rich enamel as a microstructural element that acts as a path for color transmission, although the native color remains indistinguishable from that of regular enamel, challenging the prevailing paradigms. The redefinition of “pigmented enamel” to encompass ferrihydrite-like infusion in rodent incisors reshapes our perception of incisor microstructure and color generation. The functional significance of acid-resistant iron-rich enamel and the understanding of the underlying coloration mechanism in rodent incisors have far-reaching implications for human health, development of potentially groundbreaking dental materials, and restorative dentistry. These findings enable the creation of an entirely different class of dental biomaterials with enhanced properties, inspired by the ingenious designs found in nature.
