不同粘接剂对后牙分裂桩冠修复应力分布影响的有限元分析  

Finite element analysis of the stress distribution of two-piece post crown with different adhesives

作　　者：何立辉[1,2] 刘立杰[1] 高贝[1] 高尚[1] 陈一夫[1] 刘志辉[1] 

机构地区：[1]吉林大学口腔医院口腔修复科 [2]长春市美誉口腔门诊部,长春130021

出　　处：《华西口腔医学杂志》2013年第4期348-352,共5页West China Journal of Stomatology

基　　金：长春市社会发展科技基金资助项目(12SF80)

摘　　要：目的建立下颌第一磨牙残根分裂桩冠修复的三维有限元模型,分析不同粘接剂粘接时残根应力分布特点,从而得到在不同情况下与分裂桩冠修复相匹配的最佳粘接剂。方法选取健康的下颌第一磨牙离体牙,沿釉牙骨质界将冠部去除,对处理后的残根进行CT扫描。将CT影像导入逆向工程软件,重建下颌后牙残根的三维有限元模型;制作与残根相匹配的纯钛分裂桩冠修复体,同样进行CT扫描,在MIMICS中重建出修复体的模型,并进行装配,对比分析不同粘接系统在垂直载荷及侧向载荷下对根管内部及残根断面应力的分布特点。结果建立了下颌第一磨牙残根的三维有限元模型及分裂桩冠有限元模型,并进行匹配安装。随着粘接剂弹性模量的增加,根管内的最大应力也在增加,磷酸锌的弹性模量最大,根管内承受的应力最大;Superbond C&B的弹性模量最小,根管内承受的应力最小,且侧向载荷的应力要远大于垂直载荷。在垂直载荷下,对于不同粘接剂,施加在残根断面的载荷比较平均。在侧向载荷下最大应力要远大于垂直工况。使用磷酸锌粘接剂时残根断面的应力最小,使用SuperbondC&B时残根断面应力最大。结论在分裂桩冠修复后牙残根时,不同的粘接剂对牙体组织的应力保护作用有很大区别。当根管口处牙体组织较为薄弱时,为避免其发生劈裂,建议采用弹性模量较大的粘接剂,如磷酸锌;当根管口处牙体组织抗力形较好而牙根较细或根管壁薄弱时,建议采用弹性模量较小的粘接剂,如Superbond C&B。Objective To establish three-dimensional finite element model of two-piece post crown to the man- dibular first molar residual roots, and analyze the stress distribution characteristic to the residual roots with different adhesives, so as to get the best combination under different conditions. Methods The complete mandibular first molar in vitro was selected, the crown was removed along the cemento-enamel junction, then the residual roots were scanned by CT. CT images were imported into a reverse engineering software, and the three-dimensional finite element model of the mandibular first molar residual roots was reconstructed. Titanium two-piece post crown of the mandibular first molar residual roots was produced, then was scanned by CT. The model was reconstructed and assembled by MIMICS. The stress distribution of the root canal and root section under the vertical load and lateral load with different bon- ding systems were analyzed. Results Three-dimensional finite element model of two-piece post crown to the mandi- bular first molar residual roots was established. With the increasing of elastic modulus of the adhesives, the maxi- mum stress within the root canal was also increasing. Elastic modulus of zinc phosphate was the biggest, so the stress within the root canal was the biggest; elastic modulus of Superbond C＆B was the smallest, so the stress within the root canal was the smallest. Lateral loading stress was much larger than the vertical load. Under vertical load, the load on the root section was even with different bonding systems. Under lateral load, the maximum stress was much larger than the vertical load. The stress on the root section was minimum using zinc phosphate binder, and the stress on the root section was maximum using Superbond C＆B. Conclusion In two-piece post crown restorations, there is significant difference between different adhesives on tooth protection. When the tooth structure of the root canalorifices is weak, in order to avoid the occurrence of splitting, the larger elastic m

关 键 词：粘接剂 分裂桩冠 三维有限元 

分 类 号：R783[医药卫生—口腔医学]