利用三维有限元分析根尖切除对上颌中切牙生物力学性能的影响  

The Effect of Apical Resection on Biomechanical Properties of Maxillary Central Incisor by Three-Dimensional Finite Element Analysis

作　　者：羊茜[1] 冉淑君[2,3] 王冬梅 刘斌[2,3] YANG Xi;RAN Shujun;WANG Dongmei;LIU Bin(School of Mechanical and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Department of Teeth and Pulp,Shanghai Ninth People＇s Hospital,Shanghai Jiao Tong University School of Medicine,Shanghai 200011,China;National Clinical Research Center of Stomatology,Shanghai Key Laboratory of Stomatology ＆ Shanghai Research Institute of Stomatology,Shanghai 200011,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240 [2]上海交通大学医学院附属第九人民医院牙体牙髓科,上海200011 [3]上海市口腔医学重点实验室,上海市口腔医学研究所,国家口腔疾病临床研究中心,上海200011

出　　处：《医用生物力学》2018年第4期337-342,共6页Journal of Medical Biomechanics

基　　金：上海交通大学医工交叉基金项目(YG2016MS13)

摘　　要：目的研究根尖切除手术后牙体及牙周应力分布的变化以及牙齿的位移,为临床医师实施根尖手术提供数据支持,提高根尖手术治愈率。方法基于Micro CT图像数据建立正常上颌中切牙及其牙周组织的三维有限元模型。在此基础上仿真根尖周炎和根切治疗手术,并建立根尖周炎及不同根切长度（3、4、5、6、7、8 mm）上颌中切牙及其支持组织的三维有限元模型,施加咬合力,通过三维有限元仿真分析,研究术后愈合牙齿的生物力学行为特性,对比分析手术修复的生物力学效果,得到最佳的根尖切除长度。结果根尖切除手术术后,愈合模型降低患牙的应力水平（26.8%）及牙齿动度（7.3%）;随着根切长度的增加,根切达8 mm时,牙齿颈部和牙周膜的应力分别增加11.14%和29.27%,牙槽骨的应力增加83.11%,切面形成的新的根尖处应力相较于正常牙齿相同部位整体上升;牙齿沿长轴的位移也逐渐增大,当根切超过5 mm时,位移水平明显增大（18.39%）。结论根尖切除手术对于难治性根尖周炎患牙的生物力学特性有明显改善,建议临床手术中根尖切除长度范围为3～5 mm,冠根比不低于0.84。Objective To study the tooth and periodontal stress distribution and tooth displacement after apical root resection,so as to provide data support for clinicians to perform apical root surgery and improve the cure rate of apical root surgery. Methods Three-dimensional（ 3D） finite element model of normal maxillary central incisor with its periodontal tissues was established based on Micro CT image data. Then periapical periodontitis and apical root resection surgery were simulated. The model of periapical periodontitis and maxillary central incisor with different apical root resection length（ 3,4,5,6,7,8 mm） and their supporting tissues were established. With the occlusal force applied,the biomechanical behavior of postoperative healing teeth was studied by 3D finite element analysis. The optimal apical resection length was obtained by comparing biomechanical effects of surgical restoration. Results The completely healed model reduced the stress（ by 26.8%） and displacement（ by 7.3%）compared with the apical periodontitis model. With the increase of apical root resection length,the stress of the teeth neck and periodontal ligament increased by 11. 14% and 29. 27%,respectively,when the root resection was 8 mm. The stress of the alveolar bone increased by 83. 11%. The stress of new apical root at the section increased on the whole compared with the same part of normal tooth. The displacement of the tooth along the long axis also increased. The displacement significantly increased by 18. 39% when the resection length was over5 mm. Conclusions Apical root resection significantly improves the biomechanical properties of refractory apical periodontitis tooth. The recommended resection length was 3-5 mm and the crown-to-root ratio（ CRR） should be larger than 0. 84.

关 键 词：显微根尖手术 中切牙 牙周组织 生物力学 有限元分析 

分 类 号：R318.01[医药卫生—生物医学工程]