- 學位論文
液晶環氧樹脂應用於牙科矯正托架
Liquid Crystalline Epoxy Resin for Orthodontic Brackets
摘要
目的: 探討液晶環氧樹脂作為牙科矯正托架之材料配方的可行性。 實驗方法: 以液態環氧樹脂3,4-epoxycyclohexylmethyl-(3,4-epoxy) cyclohexanecarboxylate (ECH)，加入定量的液晶環氧樹脂Biphenyl and tetramethyl biphenol epoxy resins (BPs) epoxy resin與硬化劑Hexahydro-4-methylphthalic Anhydride (HMPA)來製備液晶環氧樹脂。製作出不同重量百分濃度的液晶環氧樹脂並比較BPs濃度對於材料性質之影響。機械性質方面藉由硬度測試、表面粗糙度、拉伸強度、抗彎強度來表現BPs樹脂對於整體機械性質的影響；材料的染色性質測試藉由咖啡與可樂浸潤材料來評估；熱穩定性方面藉由微熱差掃描與熱重分析法分別量測材料之玻璃轉移溫度與熱裂解溫度；細胞毒性測試是藉由MG-63細胞與材料浸泡之培養液共同培養，以MTT試劑、LDH試劑評估。綜合上述性質，篩選出性質優化最高的液晶環氧樹脂配方，並藉由電腦數位控制雕刻熱聚合之樹脂塊材製作牙科矯正托架。生物相容性則是藉由動物模式評估，將本篇研究製作之液晶環氧樹脂牙科矯正托架植入小鼠模式，以動物模式評估其材料對於生物體所造成的毒性與發炎反應，以此評估材料的生物相容性。 實驗結果： 添加的液晶環氧樹脂可以強化固化後的硬度並降低加工後的粗糙度；另一方面，液晶環氧樹脂對於材料的拉伸強度與抗彎強度方面並無明顯改良，但符合矯正器材料所需要的抗彎強度。在易染色的食物色素染色結果上，液晶環氧樹脂表現良好的抗染色性質；另外，熱分析法DSC與TGA確定了BPs液晶環氧樹脂材料在口腔環境與室溫之下是穩定而不會產生變形的。細胞毒性方面，液晶環氧樹脂對於細胞並無明顯毒性。動物模式的結果以H E染色觀察，與市售材料組別比較皆無發現免疫細胞出現，表現良好的生物安全性。綜合上述結論，添加3.03 wt.%的BPs液晶環氧樹脂即可改良環氧樹脂使材料具有更好的機械強度、同時能兼顧生物安全性。 結論: BPs液晶環氧樹脂可改良環氧樹脂(ECH)使材料具有更好的機械強度、同時具有抗染色能力且兼顧生物安全性，本研究中的液晶環氧樹脂BPs03是個具有作為牙科矯正托架的材料之潛力。
並列摘要
Purpose: The purpose of this study is to evaluate the potential of a new formulation liquid crystalline (LC) epoxy resin as dental bracket material. Methods: The preparation of LC epoxy resin is based on 3,4-epoxycyclohexylmethyl-(3,4-epoxy) cyclohexanecarboxylate (ECH) as major body, biphenyl and tetramethyl biphenol epoxy resins (BPs) as mesogen and hexahydro-4-methylphthalic anhydride (HMPA) as the curing agent. To study the effect of BPs to ECH material properties, prepared BPs epoxy resin in each composition of BPs series. To show the mechanical properties improvement, hardness, surface roughness, tensile strength and flexural strength were studied and measured. The stainability was performed by using coffee and cola as staining solutions to evaluate the color difference of BPs epoxy resin and commercial product. The thermal stability was determined by Tg and Td using DSC and TGA analysis. The cytotoxicity was conducted by MG-63 cells with extracts of BPs using MTT and LDH tests. Determined the optimal formulation of BPs and fabricated the BPs orthodontic bracket using the computer numerical control (CNC) 3D milling machine. Results: The hardness and roughness are improved by adding BPs; BPs has no effect on both tensile and flexural strength properties. Also, BPs epoxy resin showed a good stainability that won’t be stained by coffee and cola. The thermal stability tests showed BPs epoxy resins were safe and stable when using in oral environment and room temperature. BPs showed no significant cytotoxicity to MG-63 cell, and histological analysis of mouse model showed BPs with a good biocompatibility. To sum up, adding 3.03% LC epoxy resin (BPs) to ECH has improved the mechanical properties of epoxy resin and also showed a good biosafety. LC epoxy resin BPs03 in this study is a novel material that has the potential using in dental bracket. Conclusion: By incorporating BPs with ECH, the results showed a greatly improvement on mechanical properties and showed good stainability and biocompatibility. BPs03 in this study is a novel material that has the potential using in orthodontic bracket.