| Summary: | 碩士 === 國立中正大學 === 機械工程系研究所 === 106 === Tooth enamel exhibits intricate microstructure and hierarchical organization. Material with such common architecture often possesses amazing mechanical property and tribological performance. The proposed study embarks on an investigation of various tooth enamel of different dietary and environment to explore the key elements of microstructure display such extraordinary physical property.
This study characterized the mechanical property and microstructure of various tooth enamel from the utmost outer layer of the enamel surface to the enamel-dentine junction, this study collected a variety of animal teeth of different diet to study enamel surface microstructure, the mechanical properties of the cross section, and the organic composition distribution, comparing the differences between each other and evolution. Instrumental indentation with depth sensing technique was employed to obtain the hardness and elastic modulus. Atomic force microscopy will provide microstructural features such as prism arrangements. Module mapping technique will be used to understand the inorganic and organic composition. An array of surface analysis including FTIR will be used for element analysis to obtain inorganic and organic composition. Calculate prism area ratio and prism size by MATLAB Image Processing Tool Software codes.
Observing the microstructure of tooth enamel, it was found that mammals had developed the prism. After further exploration, it was found that prism contained significant viscoelastic distributions and that herbivorous prism were known is oval. Measuring the surface layer of the teeth to DEJ (Dentin Enamel Junction), we can know that the teeth are not uniform materials, and then find the control factor of the cross section hardness gradient is the loss modulus, and its composition is phosphate . Animals must use tooth to survival, so the teeth with functional gradient performance become indispensable important role. The ability to give the tooth such excellent mechanical properties is to control the hardness gradient properties through the phosphate content of the teeth, so that the teeth can resist large external forces without breaking.
The results show that enamels of different animal exhibit gradient from the outmost surface to DEJ.Finding from computational analysis indicate that gradient of the enhance the ability of absorb the energy induce by stress .The strikes similarity in gradient feature and prism arrangement of enamel of teeth from animals of different diet, environment and evolution tree unravel the lessons provide by mother nature. It is indeed marvelous the a minute amount of organic can create a robust microstructure composite. From this aspect to explore bio-mineralized materials from which to learn and inspire.
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