- 學位論文
具緩衝機制之新型人工牙根設計及分析
Design and analysis of a novel implant with buffering mechanism
摘要
隨著科技進步所發展出的人工牙根系統，已廣泛成為缺牙患者於治療上重要的選擇，由文獻得知人工植牙的成功取決於植牙之初期穩定度及術後骨整合情形，亦指出可於牙植體中加入彈性體來達到緩衝及吸震之功用以符合自然牙之力學特性。故本研究利用有限元素分析探討具緩衝機制新型人工牙根之生物力學行為。首先，論文第一部份為根據三家不同廠牌的臨床牙植體來建立有限元素模型，分別為台灣植體、Branemark牙植體及Ti-one101牙植體廠商所市售之牙植體，評估三種不同幾何外形參數之牙植體對於齒槽骨上的應力之影響，並選擇具有較佳力學表現的牙植體作為接續設計新型牙植體之外形。論文第二部份則為新型緩衝人工牙根之設計，利用發泡材料之彈性體及圓錐形彈簧來達到位移，其設計目標以避免緩衝體外露及達到自然牙特性為目的，觀察當牙植體受力後之力量-位移曲線及齒槽骨上應力分佈情形，並與傳統牙植體相互比較。第一部分結果顯示，三種牙植體應力皆集中於皮質骨且最大盟麥斯應力無明顯之差異，但在路徑應力結果，Branemark牙植體有最佳之力學特性，因此選擇Branemark牙植體螺紋設計作為新型緩衝牙植體之基本模型。第二部分結果顯示，新型緩衝牙植體之力量-位移曲線呈現兩段不同斜率之曲線，在初始承受負載時即可產生大位移，接著，則需更大的負載才能使之位移，此力學性質類似於自然牙之特性。且與傳統植體相比較，發現可達到延遲負載傳遞至齒槽骨以及減少齒槽骨應力之優點。未來將製造本研究所設計之新型緩衝人工牙根原型，並進一步測試其生物力學表現，以期未來能實際於臨床上使用。
並列摘要
With the advancement of science and technology, dental implant system has become an important treatment option for edentulous patients. A successful dental implant treatment depends on the initial stability and osseointegration as found from previous literatures. Some literature also pointed out that by adding elastomeric component into the dental implant system can provide cushioning and shock-absorbing capabilities of a natural tooth. Therefore, the aim of this study was to design and analyze the biomechanical behavior of a novel dental implant system with buffering mechanism by using finite element analysis. In the first part of the study, three different commercial dental implants including Taiwan implant, Branemark implant, Ti-one 101 implant were analyzed by observing the stress on the alveolar bone and the performances of the three dental implants were evaluated. The thread geometry of the novel dental implant system was created based on the Branemark thread design. In the second part of the study, the novel dental implant with an elastomeric component or with a conical spring was designed to provide the similar mobility of a natural tooth. The objective of the design was to avoid the exposure of the elastomer to outside oral fluid and to achieve the biomechanical mobility of a natural teeth. The force-displacement curve of the novel dental implant and the stress distribution of the surrounding alveolar bone were observed under axial and lateral loading conditions. Furthermore, the results were compared with those of a traditional dental implant without the buffering mechanism. The results from the first part of the study showed that the stresses are concentrated on the cortical bone for all three commercial implants. However, there was no significant difference on the maximum von Mises stress for all three commercial dental implants. The thread geometry of the Branemark implant was selected for the novel implant for its better mechanical characteristic according to the stress patterns. As seen from the force-displacement curves of the novel dental implant, it exhibits a larger displacement during the initial loading condition; but only little displacement was allowed when larger loading was applied. The biomechanical behavior of the novel implant is similar to that of a natural tooth. The novel dental implant could provide initial mobility and delayed loading capability and could therefore decrease the stress on the alveolar bone as compared with the conventional dental implant. The fabrication of this novel dental implant is underway and its biomechanical performance will be further tested. It is hoped that its clinical application can be realized in the future.