利用原子層沉積技術改質牙科植體表面及其表現之研究

Abstract

牙科植體（dental implant）於近年來蓬勃發展，是當前受矚目的牙科治療技術。透過人工牙根與患者齒槽骨達成骨整合（osseointegration），使病人在無牙區的贗復上能有更能承受咬合力量的治療選擇，在過往的研究中顯示牙科植體的表面處理方式對於骨整合的成功與否影響深遠。 當前最廣泛使用的人工牙根材料以商業級純鈦（commercially pure titanium, CPTi）及鈦六鋁四釩（Ti6Al4V）等鈦金屬為主。此類鈦金屬在自然環境下會在極短時間內形成二氧化鈦保護層（passive layer），然而此二氧化鈦保護層為非晶形（amorphous）結構，且厚度只有約5–6奈米。為了產生緻密度更佳、厚度更厚的二氧化鈦保護層以提供更好的成骨細胞（osteoblastic cells）生長環境，將使用原子層沉積技術（atomic layer deposition, ALD）於純鈦及鈦六鋁四釩表面成長二氧化鈦鍍膜，測試厚度包含0奈米，20奈米，50奈米，100奈米；測試晶形包含非晶形與銳鈦礦形（anatase）二氧化鈦。我們預期經由原子層沉積技術成長二氧化鈦保護層的鈦金屬能提高其生物相容性（biocompatibility）。 本研究主要分為材料分析及細胞實驗兩個主要部分。材料分析方面包含電子顯微鏡（scanning electron microscope, SEM）以及原子力顯微鏡（atomic force microscope, AFM）。細胞實驗部分包含細胞存活率（cell viability）、鹼性磷酸酶試驗（alkaline phosphatase assay, ALP assay）、骨鈣素試驗（osteocalcin assay, OCN assay）以及免疫螢光染色試驗（Immunofluorescence assay, IFA）。

Dental implant has been very popular nowadays, and implant therapy has also been in the limelight. By osseointegrated with patient’s alveolar bone, dental implants provide dentists another prosthetic treatment choice which can bear more occlusal force during chewing. Previous research pointed out that implant surface treatment may play an important role on implant osseointegration. The most commonly used dental implant materials are commercially pure titanium and Ti6Al4V. In natural environment, these titanium alloy mantles a cover of titanium dioxide passive layer in short time. Nevertheless, the cover of titanium dioxide is amorphous type and its depth is about 5-6 nm. For producing a more intensive and thicker cover of titanium dioxide to provide better environment for osteoblastic cells, atomic layer deposition technique is used. In this research, we tested four different thickness（0 nm, 20 nm, 50 nm, 100 nm）and two different crystal forms（amorphous, anatase）of titanium dioxide. Thicker titanium dioxides passive layer as expected to be more biocompatible. This research has two main parts, material analyses and cell experiments. Atomic force microscope, scanning electron microscope were carried out in material analyses. Cell viability, alkaline phosphatase assay, osteocalcin assay and immunofluorescence assay were carried out in cell experiments.