由牙齒牙釉質之功能梯度性質來探討前瞻材料的準則

Tooth Enamel Functionally Graded to Explore Unprecedented Engineering Material Guidelines

陳柏蒼(BO-CANG CHEN)

指導教授 ： 鄭友仁

國立中正大學/工學院/機械工程學系/碩士(2016年)

摘要

生物礦物化材料呈現錯綜複雜的微觀結構和層次組織，具有這此精巧的組織架構之生物材料往往展現驚人的力學性質和磨潤性能。其中牙齒的牙釉質是礦化物最高的生物材料之一，近年的研究發現人類牙釉層的功能梯度特徵及奈米結構是形成優異的機械物理性質的關鍵。本研究將對於不同的食性和環境之各物種牙齒牙釉質之機械物理性質探討，以探索材料微觀結構和功能性梯度性質間的關係。
為了探討不同食性之各物種牙釉質由外層表面漸序至內層之漸進效應的機械性質和磨潤性能，我們收集了多種動物:牛、鹿、人、貓、海豚、鱷魚、蝙蝠、水獺、白鯨、羊駝、美洲黑熊、班鬣狗、臭鼬、北美負鼠、二趾樹櫴、赤狐、兔子、浣熊、美洲旱獺、石龍子及美洲鬣蜥等二十二種動物牙齒，研究琺瑯質表面微觀形貌及橫結面的機械性質，比較彼此間的差異性。本實驗將透過原子力顯微鏡(Atomic Force Microscope,AFM)了解牙齒表面微結構，奈米壓痕儀(Nano Indentation)利用深度感測技術進行極小尺度壓痕，以獲得硬度和彈性模量。奈米刮痕試驗(Nano Scratch)將用來量測磨耗性能。物理性質係數相圖技術(Modulus mapping)可評估黏彈性的分布。精密動態分析技術(Dynamic Mechanical Ananlysis, DMA)可了解到琺瑯質內的黏彈性質。
透過原子力顯微鏡觀察牙齒琺瑯質表面形貌，發現哺乳類動物已發展釉桿柱微結構，再以奈米壓痕儀進行探討，得知釉桿柱的排列密度高，表面硬度也就越高，排列組合較鬆散的，表面硬度也就越低。量測牙齒表面到DEJ處的梯度性質與黏彈性能，可以發現橫截面硬度梯度就是靠著損失模數來控制的，透過牙齒的黏彈性質來分配有機物與無機物比例來控制硬度梯度性質，得以讓牙齒擁有良好的機械性質。

關鍵字

黏彈性質 ； 功能梯度 ； 釉桿柱排列

並列摘要

Biomineralization material exhibits intricate microstructures and hierarchical organization, with which this compact organizational structure of biological materials tend to exhibit astonishing mechanical properties and tribological performance. Wherein the tooth enamel is one of the highest biological material mineralization, recent studies have found that functionally graded and nanostructure characteristics of human enamel layer is the key to the formation of excellent mechanical and physical properties. In this study, the mechanical and physical properties of each species different feeding habits and environment of the tooth enamel discussed in order to explore the relationship between material microstructure and properties of functional gradient .
In order to explore the different feeding habits of each species enamel gradually progressive sequence from the outer surface to the inner effect of the mechanical properties and tribological performance , we collected a variety of animals: cattle, deer, human, cats, dolphins, crocodiles , bats, beaver, whales, luma, American bear, hyena , skunk, opossum, sloth , fire fox, rabbit, raccoon, woodchuck, skinks and iguana and other twenty-two animals dental.Research enamel surface morphology and mechanical properties of the cross-junction, compare with the differences between them. The experiment will be appreciated that the tooth surface microstructure through AFM (Atomic Force Microscope, AFM), nano indenter (Nano Indentation) depth-sensing technology for small scale indentation, to obtain hardness and elastic modulus. Nano scratch test (Nano Scratch) will be used to measure the wear performance. Physical properties coefficient phase diagram technique (Modulus mapping) to assess the distribution of viscoelasticity. Precision dynamic analysis (Dynamic Mechanical Ananlysis, DMA) can be learned within the viscoelastic properties of the enamel.
Microscope tooth enamel surface morphology through an atomic force found that mammals have developed the post enamel microstructure, and then to explore the nano indenter, that the high-density arrangement of enamel rod string, the higher the surface hardness, permutations and combinations looser, lower surface hardness. Measured tooth surface to the gradient and viscoelastic properties at the DEJ can be found cross-sectional hardness gradient is relying loss modulus controlled through the viscoelastic properties of the teeth to be allocated in proportion to the organic and inorganic hardness gradient control nature, to be let teeth with good mechanical properties.

並列關鍵字

viscoelastic properties ； functionally graded ； arrangement of enamel rods

參考文獻

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