- 學位論文
添加奈米級二氧化鈦的玻璃離子體黏合劑特性之研究
Properties of Glass Ionomer Cement Added with Nano-Sized Titanium Dioxide
摘要
玻璃離子體黏合劑 (glass ionomer cement，GIC) 因為擁有良好的機械性質以及生物相容性，因此被廣泛應用於牙科臨床牙齒窩洞的填補以及贋復物黏著劑的使用。奈米級二氧化鈦 (TiO2) 對人無毒性且可進行光觸媒反應而有抗菌、自潔的效果。大量口腔微生物暴露在口腔環境中，所以容易在填補材料與牙齒界面間藏有大量細菌而引起繼發性齲齒的產生。本研究的目的在於利用二氧化鈦的優點，發揮牙科玻璃離子體黏合劑之長處，探討添加奈米級二氧化鈦粉末對牙科玻璃離子體黏合劑機械性質、抑菌性以及生物相容性之影響。 在實驗中將兩種不同粒徑大小 (ψ15 nm、ψ<25 nm) 的奈米級二氧化鈦粉末以0.5、1.0、3.0及5.0 wt %比例分別加入至玻璃離子體黏合劑材料中，製成圓盤狀 (直徑4mm x 高度2mm) 試片，未加入奈米級二氧化鈦粉末的原始黏合劑材料為對照組。進行了機械性質和抑菌實驗。抑菌實驗選用了兩種常見的人體口腔疾病菌，血鏈球菌 (Streptococcus sanguis，Ss) 以及牙齦卟啉菌 (Porphyromonas gingivalis，Pg)，將各組試片放入含有Ss菌或是Pg菌的專用液態培養基中，在經過24、48、72小時後進行菌液濁度分析。同時也利用紫外光 (Ultraviolet，UV) 對實驗及對照組試片各照射30分鐘，再進行抑菌性測試評估抑菌效果。此外也對實驗材料進行了細胞活性分析 (MTT assay)。 實驗結果顯示，添加奈米級二氧化鈦粉末的實驗組0.5、1.0 wt %與對照組相比其抗壓強度、對徑壓縮強度有稍微提升，但二者在統計學上並無顯著的差異性 ( p>0.05)。在抑菌作用方面，實驗組1.0 wt %的抑菌效果比對照組好 ( p<0.05)，有照射紫外光的實驗組1.0和5.0 wt %其抑菌效果也比未照射的實驗組有更良好的抑菌效果 ( p<0.05)。在細胞活性分析方面，奈米級二氧化鈦能大幅提升材料對於牙周韌帶細胞的生物相容性 ( p<0.05)。本研究結論是，添加1.0 wt %奈米級二氧化鈦粉末不會影響玻璃離子體黏合劑的機械性質，而且能提升抑菌效力以及生物相容性。
並列摘要
Glass ionomer cement (GIC) has been widely used in the oral cavities for dental cavity filling or restorative cementing by dentists for its good mechanical properties and high biocompatibility. The material is exposed to vast amount of oral bacteria; therefore, the purpose of this study is to evaluate the influences of nano-sized titanium dioxide (TiO2) addition into GIC on the growth of Streptococcus sanguis (Ss) and Porphyromonas gingivalis (Pg), two common microorganisms which may lead to human oral diseases. Moreover, the effects of added TiO2 on cell vitality were examined when co-cultured them with GIC. Two different particle sizes of TiO2 (ψ15 nm and ψ<25 nm) were added when preparing GIC discs, respectively. To facilitate the photocatalysis of TiO2, half of the samples were irradiated by UV for 30 min. GIC discs then were immersed in media containing Ss or Pg. The values of bacterial turbidity were measured after 24, 48 and 72 hours of incubation. We observed that the addition of 0.5-5.0 wt% TiO2 into GIC did not influence the mechanical properties ( p>0.05). The bacterial numbers were significantly lower in the presence of TiO2 1.0 wt% comparing to GIC without TiO2 addition ( p<0.05), and even lower in the 1.0 wt% and 5.0 wt% groups of UV irradiation ( p<0.05). After incubation of the periodontal ligament cells in the presence of GIC, the cell numbers were significantly higher in the presence of TiO2 comparing to GIC without TiO2 addition ( p<0.05). We concluded that the addition of 1.0wt% TiO2 into GIC did not influence the mechanical properties , but can inhibit oral bacterial growth and enhance cell compatibility.