根管治療後正中門齒補綴之應力分析

Stress Analysis of Post-Endodontic Restoration in Central Incisor

張耀文(Yao-Wen Chang)

指導教授 ： 陳文斌

中原大學/理學院/應用物理研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200032

摘要

根管治療後的牙齒較容易發生牙冠－牙根的斷裂型態。雖然目前補綴根管治療後牙齒的方式很多，但沒有一個標準的規範。本研究主要利用有限元素法模擬各式Class I補綴之正中上顎門齒的三維有限元素模型，探討補綴材料、補綴深度，在不同負載情形下對牙本質應力分佈的影響，根據結果，再更進一步利用窩洞幾何形狀設計的方式，探討補綴幾何形狀對牙本質內應力分佈改變的影響，及引導斷裂的可能性。結果顯示，以汞齊合金或複合樹脂為材料之一般Class I補綴，當補綴深度超過齒頸部時，於齒頸部深度的牙本質內會產生應力集中的現象，可能導致未來發生牙冠－牙根斷裂的機率上升；因此，對於臨床上之門齒的一般Class I補綴，建議以較硬的材料僅補至舌窩以下3mm，可能可以防止產生牙冠－牙根斷裂之斷裂型態。另外，若以汞齊合金或複合樹脂為材料之特殊幾何形狀進行較淺層的補綴，可降低齒頸部的高應力集中現象，並增加牙冠以上牙本質內的應力集中情形，可能具有引導斷裂的功能。凡以玻璃水門汀為補綴材料之門齒，在應力分布的表現上皆與根管治療後尚未補綴之門齒相同沒有差異。

關鍵字

有限元素法 ； 補綴 ； 根管治療 ； 應力 ； 斷裂 ； 門齒

並列摘要

Crown-Root fracture occurs more frequently in teeth that received endodontic treatment. Although various methods of restoration are used, no typical rules have been brought up at present. In this study, three-dimensional finite element models were used to simulate different types of Class I restoration of maxillary central incisor. The specific aims of this study were to investigate the effects of stress distributions of an incisor restored with: 1. different materials; 2. different depths; 3. different cavity designs. The results showed that stress concentration increased at the cervical dentin when amalgam or composite resin was used in Class I restoration. This may increase the possibility of crown-root fracture in the future. Therefore, harder restorative material with less filling depth was suggested in this study for clinical practice. In addition, it may reduce the high stress concentration in the cervical portion, and increase the stress in the dentin above cementum-enamel-junction. According to these findings, guiding fracture using special restoration geometry may be possible if amalgam or composite resin is used. There is no significant stress difference in the dentin for glass ionomer restoration when compared with that of an opening incisor.

並列關鍵字

Finite element method ； stress ； endodontics ； incisor ； restoration ； fracture

參考文獻

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