中国实用口腔科杂志

中国实用口腔科杂志

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不同冠根比平台转换结构种植义齿应力分布三维有限元分析

江鹭鹭1，蔺    增2，邓春富1，尚德浩1，张    翀1，王丹宁1，张馨文1，何    晶1，赵宝红1   

  1. 1. 中国医科大学口腔医学院种植中心，辽宁省口腔医学研究所，辽宁  沈阳  110002；2. 东北大学机械工程与自动化学院，辽宁  沈阳  110004
  • 出版日期:2016-05-15 发布日期:2016-06-14
  • 基金资助:

    辽宁省自然科学基金（20092093）；辽宁省科技计划项目（2013225049）；沈阳市科技计划项目基金（F11-264-1-25）

  • Online:2016-05-15 Published:2016-06-14

摘要：

目的    比较不同冠根比的平台转换结构种植义齿对种植体及其周围骨组织应力分布及应力变化趋势的影响。方法    建立平台转换结构种植义齿修复下颌第一磨牙的三维有限元模型。将种植体与基台、基台与螺钉、螺钉与种植体之间设置为摩擦接触，摩擦系数为0.3。冠根比分别为1∶1.5 、1∶1 、1.5∶1 、2∶1 和3∶1。分别进行垂直向及斜向加载，运用Ansys Workbench 14.0分析比较各组模型Von Mises应力峰值分布情况及应力变化趋势。结果    垂直加载下不同冠根比的各组模型整体应力分布较为均匀，Von Mises应力峰值变化不明显。当冠根比为1.5∶1时，种植体颈部出现最大应力值。应力集中区出现在种植体颈部与基台及基台与中央螺丝连接处；斜向载荷下，随着冠根比的增大，各组模型Von Mises应力峰值明显增大，冠根比为3∶1时种植体和中央螺丝的应力峰值约为1∶1时的3倍，其余部件约增大1倍。应力集中区与垂直载荷下相一致，但Von Mises最大应力出现在基台上。结论    在摩擦接触条件下，平台转换结构能够有效地转移种植体的应力集中区，减少牙槽骨吸收。在冠根比较大时，应采取有效措施减小义齿斜向受力。

关键词: 种植义齿, 三维有限元, 平台转换, 冠根比, 摩擦接触

Abstract:

Objective    To compare the influence of  platform switching configuration implants with different crown root ratios on the distribution and changing trend of stress in implants and the surrounding bone. Methods    Establish the three-dimensional finite element model of platform switching configuration implant for the repair of mandibular first molar. The contact relationship between implant and abutment，abutment and screws，screws and implants was set for frictional contact，and 0.3 was taken as the friction coefficient. Ansys Workbench 14.0 software was used to analyse and compare the distribution of Mises Von maximum stress and the trend of the stress change in different models under vertical or oblique loading. The crown root ratio of the implants was 1∶1.5，1∶1，1.5∶1，2∶1 and 3∶1 respectively. Results    Under the vertical loading， the stress distribution of the models with different crown root ratio was more uniform and the change of Mises Von maximum stress was not obvious. When the crown root ratio was 1.5∶1，the maximum stress value appeared in the neck of the implant. Stress concentration zones appeared in the connection between neck of implant and abutment，and also occurred between abutment and central screw connections. Under the oblique loading， with the increases of crown root ratio，the Mises Von maximum stress of each model increased significantly. When the crown root ratio was 3∶1，the stress peak of the implant and the central screw was nearly three-fold of that of 1∶1，and the stress peak of the rest components almost doubled. The stress concentration area was consistent with the vertical loading，but the maximum Mises Von stress appeared in the abutment. Conclusion    Under the condition of frictional contact，the platform switching configuration can effectively transfer the stress concentration area of the implant，and then reduce the absorption of the alveolar bone. At the same time，when the crown root ratio is relatively large，the effective measures should be taken to reduce the oblique stress of the denture.

Key words: dental implant, three-dimensional finite element, platform switching, crown root ratio, frictional contact