微型种植体直径和长度优化设计在Ⅳ类骨质中应力分布的三维有限元分析  

Optimized design of mini-implant diameter and length in IV osteoid through threedimensional finite element analysis

作　　者：周冠军[1] 李晨曦[1] 焦晓丽[2] 刘一冰[3] 单丽华[1] 

机构地区：[1]河北医科大学第二医院口腔正畸科,河北省石家庄市050000 [2]武警后勤学院附属医院口腔科,天津市300161 [3]河北医科大学第三医院口腔科,河北省石家庄市050000

出　　处：《中国组织工程研究》2016年第12期1812-1817,共6页Chinese Journal of Tissue Engineering Research

摘　　要：背景:为微型种植体的直径和长度影响其稳定性,目前相关研究多在Ⅰ和Ⅱ类骨质中进行,在Ⅳ类骨质中进行的研究较少。目的:通过三维有限元研究微型种植体直径和长度在Ⅳ类骨质中优化设计。方法:建立种植体-颌骨实体模型,在种植体顶部施加2 N的正畸力,方向垂直于种植体长轴,与远中轴成30°夹角,将种植体设计为不同的直径(直径为1.2-2.0 mm)和长度(骨内段长度为6-10 mm),评估颌骨的应力峰值和位移峰值,并分析对应力值对变量的敏感度。结果与结论:种植体的应力和位移主要集中在颈部,种植体-骨界面的应力主要集中在种植体-皮质骨骨界面的接触区,松质骨内的应力比较小,皮质骨内的应力减弱较快。在种植体长度恒定不变时,种植体直径对骨组织的应力影响比较大,骨组织的应力随种植体直径的增加而降低;在种植体直径恒定不变的情况下,种植体长度对骨组织的应力影响不明显;骨组织的应力及位移对种植体直径变化比较敏感,对种植体长度变化不敏感。结果表明,种植体直径对骨组织的应力分布影响比较大,其长度对骨组织的应力分布影响不大,种植体直径大于1.5 mm比较适合应用于Ⅳ类骨质。BACKGROUND： Diameter and length of mini-implant have effects on its stability, which has been reported mostly in I and II osteoid, but less in IV osteoid. OBJECTIVE： To optimize the design of mini-implant diameter and length in IV osteoid by a three-dimensional finite element analysis. METHODS： Implant-mandible solid model was established. A 2 N orthodontic force that was perpendicular to the long axis of the implant and at a 30° angle with the distal central axis was applied onto the top of the implant. The implant was designed for different diameters（1.2-2.0 mm） and lengths（6-10 mm）. Peak stress and peak displacement of the mandible were mechanically assessed, and stress sensitivity variables were analyzed. RESULTS AND CONCLUSION： The stress and displacement of the implant were mainly concentrated in the neck of the implant. The stress of implant-bone interface mainly focused on the contact area of the implant-cortical bone interface, and the stress of the cancellous bone was relatively small, but the stress of the cortical bone was weakened faster. When the implant length was constant, the implant diameter had a great effect on stress changes, and the stress of bone tissue was reduced with the increase of implant diameter. When the implant diameter was constant, the implant length had no significant effect on the stress of bone tissue. To sum up, the stress of bone tissue and displacement were sensitive to the change of implant diameter rather than the change of implant length. These findings indicate that implant diameter has a greater effect on stress distribution of bone tissue than the implant length, and the implants with 1.5 mm in diameter are suitable for IV osteoid.

关 键 词：牙种植体 牙应力分析 牙骨质 组织工程 生物材料 口腔生物材料 微型种植体 支抗 Ⅳ类骨质 有限元分析法 应力分布 直径 长度 

分 类 号：R318[医药卫生—生物医学工程]