新型人工牙根之設計與有限元素分析

Design and Finite Element Analysis of a Novel Dental Implant

董佩茹(Pei-Ru Dong)

指導教授 ： 陳文斌 ； 林俊彬

國立臺北科技大學/機電學院/機電整合研究所/碩士(2010年)

摘要

人工牙根已成為局部或全口缺牙患者之重要治療選擇，而植牙之成功與否，骨整合為重要關鍵之一。良好的初始穩定性可提升植體骨整合能力與植牙的存活率。此外，若植體能具有牙周膜韌帶之力學特性，則能夠緩衝咬合力以及賦予植體活動性，其功能與結構就更接近真牙。因此，本研究目的為設計一新型人工牙根可提升植體穩定性，並結合緩衝元素以提供植體活動性。
本研究分為兩大部份，第一部份藉由改變螺紋外形探討植體的穩定性，其中採用的四種植體螺紋外形包括梯形、斜方形、反轉斜方形與方形，藉由觀察植體與齒槽骨之間的相對位移以評估植體的穩定性。第二部份則是加入不同緩衝材料，觀察植體之力學行為，並與一般金屬植體作比較。緩衝材料的部份，則是選用發泡(EFM，EVA)與橡膠(NBR)材料，其材料特性為超彈性體，且應力-應變曲線與自然牙具有類似趨勢。研究中結合穩定性佳的螺紋外形與適當的緩衝體材料，設計新型的人工牙根以供參考。研究結果顯示螺紋外形影響植體初始穩定性，且方形螺紋最為穩固；而緩衝植體的移動性與自然牙相似，然而對於一般金屬植體與緩衝植體對齒槽骨應力分佈並無顯著性地差異。統整以上結果，使用方形的螺紋外形並加入緩衝體設計之新型人工牙根，可以提供植體適當穩定性與活動性。未來此一新型設計之人工牙根必頇再做修改以考慮緩衝體材料之生物相容性及植入口內之可行性。

關鍵字

人工植體 ； 立即受力 ； 緩衝材料 ； 有限元素分析 ； 牙科生物力學

並列摘要

Dental implant-abutment system has become an important treatment option for partially or fully edentulous patients. One of the major factors of a successful treatment is osseointegration. The primary implant stability can improve the osseointegration and survival rates of dental implant. Moreover, an ideal dental implant should posses the functions of periodontal ligament to provide implant resilience and mobility. Therefore, the aim of this study was to design a novel dental implant that can provide implant stability and also offer mobility with the incorporation of a resilient element.
The current study was divided into two parts, in the first part, the implant stability was evaluated by changing the thread geometries. Four different thread geometries including trapezoidal, buttress, reverse buttress and square shapes were considered. By means of observing the sliding distance between implant and bone to evaluate the implant stability. In the second part of the study, the biomechanical behaviors of using different resilient materials were compared with that of mental implants. From the results of the study, the resilient materials (foam and rubber) with hyperelastic behavior can imitate the mobility of a natural tooth. In the current study, a novel dental implant was proposed to provide a better implant stability and mobility.
The results showed that thread geometry could affect the primary stability, and the square threads provide a better performance. In terms of adding the resilient elements, the mobility of the implant is similar to that of a natural tooth. However, there was no significant difference on the bony stress distribution between the mental implant and the novel implant. In summary, the novel implant with square threads and resilient element could provide fair performance of implant stability and mobility. However, further modifications of the design are necessary and the biocompatibility and implantability of the implant need to be taken into account.

並列關鍵字

Dental implant ； Immediately loading ； Resilient material ； Finite element analysis ； Dental biomechanics

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