| 摘要: | 此研究從口腔牙周病觀點探討人工牙根植入物與心血管支架之關係，因牙周病容易使牙齒產生動搖現今較常見之治療方式為人工牙根植牙治療；另一方面牙周病菌進入血管內容易引起心血管硬化進而產生血栓，心血管支架為臨床醫師常採用之治療方式，所以本研究將採用新式奈米表面處理技術應用於人工牙根與心血管支架之生物力學之分析，藉由有限元素法觀察人工植入物與人體組織介面之受力情形，進而驗證此新式奈米表面之功能性。
鑑此，本論文將分為兩大部份，第一部份，人工牙根於生物力學之機制探討，首先藉由有限元素法觀察人工牙根與骨組織介面之受力情形，驗證此新式奈米表面特性。人工牙根泛指可替代口腔內缺牙區域之真牙置換物，臨床上此類植體材料經常採用純鈦或鈦合金，可幫助患者回復進食與說話之功能及自信。植入人工牙根後，植體表面可直接與齒槽骨緊密相連，此過程稱之為骨整合，一旦人工牙根與齒槽骨整合後，此人工牙根即具備承受咬力之功能。在1960 年Dr. P.I.
Branemark 發現鈦金屬對於人體有極佳之生物相容性並運用於口腔人工牙根之治療，經過數十年全世界科學家皆證實鈦金屬不易引起人體產生排斥或是任何過敏反應，同時也是唯一可以與骨組織產生緊密結合之金屬。第二部份，心血管支架於流體動力學之機制探討。現今許多研究發現牙周病菌進入血管後，容易引起血管內部不正常積聚，血管徑逐漸狹窄，使血液無法順暢流通，以導致血液流動速率改變。心血管支架泛指一種高科技特殊環狀金屬網，這種微小之管狀不銹鋼，
設計了各種長度以及直徑，放置在患者產生血栓之部位。放置時，支架被引導到施術部位，首先撐開氣囊，使支架固定後取出氣囊，如此一來可維持血管的血流量，也可以有效地減少冠狀動脈心臟疾病之症狀。此心血管支架放置後，將永久地留在患者體內。心血管疾病是現代人健康之主要疾病之一，同時也是台灣10大死因前3名，其中冠狀動脈心臟病不僅危險性高，隨著現代人飲食的改變，病例數量也逐年增加中。此心血管疾病之治療方法，輕則可用藥物控制，重則需要實
施血管繞道移植手術或置入心血管支架來治療，無論選擇哪種方式，都必須視阻塞程度及患者之身心情況來做治療方式之考量。
鑑由上述，本論文擬利用電腦輔助工程分析技術結合有限元素法有效觀察人工牙根、心血管支架與組織之介面應力，以解決臨床上，無法偵測植入物與人體組織之介面受力情況，甚至也可改變各種邊界條件及參數，觀察於不同情況下受力之情形。雖然目前已有使用有限元素法分析技術應用於人工牙根與心血管支架之研究，但對於奈米之氧化層模擬之研究尚還短缺。此研究將利用電腦斷層掃瞄之影像逆向，重建真實之人體下顎骨與血管組織模型，並結合電腦模擬分析系統
探討此特殊氧化層在手術時之應力情況，評估各種不同表面處理方式及不同氧化層厚度對於應力場所帶來之效應。此研究結果期望可回饋至設計及臨床端提供有效之參考價值。
本研究結果證實附有特殊氧化層之人工牙根與心血管支架可明顯降低人體組織之應力，受力情形也隨著氧化層厚度之增加而降低；同時也發現未經過任何表面處理技術之植入物受到之應力明顯較大且分布較不均勻，證實經由表面處理技術之植入物具有效緩和金屬與血管組織之應力與破壞，本論文所建立之平台可作為新式奈米氧化層運用於植入物之優勢與未來發展之潛能。
The purpose of this study is to investigate dental implants and vascular stents from the view point of oral periodontal diseases. Periodontal disease is likely to cause loose teeth or loss and nowadays common treatments are adopted dental implants; on other hand, periodontal bacteria enters the bloodstream can lead to cardiovascular sclerosis and produce blood clots, and vascular stent treatments could recover this problem. This study will use novel surface treatment technology analysis of biomechanics on dental implants and cardiovascular stents by the finite element method to observe artificial implants and tissue interfaces stress situations, and then verify the functionalization of the novel surface treatment. Based on these findings, we will address two major issues in this study. Specific aim 1: we will investigate the effect of dental implant on biomechanical properties. The tissue response to implants with different surface treatments to examine stress distributions by three-dimensional (3D) finite element (FE) analysis. To determine the success of implant treatment, the magnitude of the maximum stresses and deformation under physiological loading must be considered. Natural teeth would be loosed due to periodontal diseases and dental implantations are the common treatments in clinical operations. Specific aim 2: we will investigate effect of heart stent on hydrodynamics. Periodontal bacterial invades into the artery, and it is potential to create the stentosis on the vessel wall. Although commercially pure titanium (cp-Ti) and stainless steel (SS) has been a reliable material for restoration in the human body. Various modifications of surfaces have been explored for achieving more rapid osseointegration and higher success rates. Surface modification methods, such as anodic oxidation, microarc oxidation, and acidic and alkaline etching, change not only the geometric surface but also the chemical property of the implant; biomechanical or chemical properties are important factors in the biological tissue response to the implant surface.
Finite element analysis (FEA) is a useful tool that applied to quantify the stress distributions and deformations in the implant and surrounding tissues, and it has been used previously to study the biomechanical behavior of various devices, including hips, knees, and spinal implants, under various loading conditions. The novel implant surface used in this study, we discussed the stresses of implants with coated layers. Evidently, surface modification provided outstanding biocompatibility and favorable tissue responses, facilitating early healing of the implants. |
