- 學位論文
利用原子層沉積技術鍍膜奈米二氧化鈦於氧化鋯植體材料表面之研究
Improving Zirconia Implants by Coating Nano-TiO2 using Atomic Layer Deposition Technique
摘要
近年來，氧化鋯已被廣泛地應用於牙科植體領域。氧化鋯植體具有良好的機械性質與化學穩定性，不僅比鈦金屬更接近自然牙齒顏色，與組織的生物相容性佳，因此被認為是理想的牙科植體材料。然而，二氧化鋯屬於生物惰性材料，造成植體植入後不易與骨組織形成穩定的界面，且其材料特性不易使用機械或化學等方式來進行表面改質，限制其發展與臨床的應用。 過往的研究已顯示奈米級二氧化鈦鍍膜對於牙科植體的種種優點，臨床上可以藉由加強二氧化鈦保護層來提升植體的生物特性。不僅如此，二氧化鈦也是原子層沉積技術中常用來鍍膜的金屬氧化物，加上其技術可以均勻、大面積、精細的控制鍍膜厚度，因此本研究將利用奈米級二氧化鈦鍍膜表面改質以優化二氧化鋯特性，提升表面生物活性並骨整合。 本研究使用原子層沉積技術(ALD)，分別鍍上0 (未鍍膜), 25, 50, 100 nm的奈米級非晶型二氧化鈦薄膜於二氧化鋯試片上，試片原始表面粗糙度介於0.5-1.1 µm，並將鍍膜好的試片分別作材料及細胞實驗。材料測試包含使用電子顯微鏡、原子力顯微鏡以及使用細微形狀測定儀量測表面型態與粗糙度；而細胞測試包含細胞存活率、茜素紅染色、骨鈣素測試以及螢光染色測定法。 由電子顯微鏡的觀察得知，越厚的二氧化鈦鍍膜層其晶體顆粒更緻密。原子力顯微鏡的3D表面型態顯示，受到二氧化鋯表面粗糙不均的結構所影響，奈米級二氧化鈦鍍膜對二氧化鋯試片的表面型態無顯著差異。細胞測試無論是在細胞存活率或礦化能力分析，結果都指出100 nm的非晶型二氧化鈦薄膜有最佳的實驗數據。螢光染色測定結果顯示鍍膜組其細胞外型較立體為多角形，細胞的絲狀偽足數量有增加。 綜合以上實驗結果，原子層沉積技術可以精準的控制奈米級二氧化鈦鍍膜厚度，而且二氧化鈦鍍膜可以促進細胞生長、加速細胞產生鈣化組織的速度，其中又以鍍膜為100 nm厚度的組別效果最佳。因此，本技術與材料應用於臨床時，可預期可以大幅提升骨整合速率與效果。
並列摘要
Zirconia has been widely used as implant materials in dental applications nowadays due to its satisfying aesthetics and mechanical properties. However, the bio-inertness of zirconia may influence the osseointegration, and then cause insufficient stability between bone to implant surface. Various approaches have been proposed to modify zirconia implant surface to enhance bone in-growth properties, particularly using micro- and nano-topography. The application of a nanostructured titanium dioxide (TiO2) coating on zirconia implant has been proposed potentially to enhance tissue or bone to implant interactions due to its chemical stability, biocompatibility, and antimicrobial properties. Therefore, the aim of this study was to investigate the surface characteristics and biological properties of zirconia implant materials coated with nano-scale titanium dioxide by using atomic layer deposition technique (ALD). The temperature-controlled atomic layer deposition (ALD) was ultilized for providing nanostructured amorphous TiO2 coatings in different coating thickness of 0, 25, 50, 100 nm on zirconia disks (Amo0, Amo25, Amo50 and Amo100, respectively), which roughness were between 0.5-1.1 µm. The surface topography analysis was surveyed including observation using scanning electron microscope (SEM), nano-scale 3D configuration with atomic force microscope (AFM) and micro-scale surface roughness by surfcorder. The biocompatibility tests were investigated by using alamar blue assay for the survival rate of human embryonic palatal mesenchyme (HEPM) cells, alizarin red staining for observation of mineralization component and process, osteocalcin assay to evaluate the potential of osteoblast mineralization, and immunofluorence assay for observing cell’s growth pattern and morphology. SEM observation revealed that the packing of nano-TiO2 particles were more compact in thicker coating thickness. The AFM results indicated that was no significant difference in nano-scale 3D configuration. The thickness of 100 nm in TiO2 coating stimulated best in alamar blue assay and mineralization assay while immunofluorence assay presented more cell pseudopobia stucture and stereoscopic morphology compare to non-coating group. To conclude, the group of Amo100 performed best in cell’s survival rate and mineralization tests. Therefore, by coating 100 nm amorphous titanium dioxide on zirconia implant could be a potential way for improving biocompatibility and osseointegration.