Ⅳ类骨质中平台转换种植体植入深度对周围骨应力的影响

The influence of placing depth of implants with platform switching on stress distribution in periimplant bone according to type Ⅳ bone

目的分析Ⅳ类骨质条件下平台转换种植体植入深度对种植体周围牙槽骨应力分布特征的影响,为平台转换种植体的临床应用提供一定的参考依据。方法利用CT扫描以及Mimics10.01、Solidwork2007等软件实体建模技术,结合有限元软件Ansys14.0建立按包含平台转换种植体及上部结构和中切牙牙冠的Ⅳ类骨质的有限元模型,并按照四种不同植入深度装配,分析垂直100N及斜向100N两种加载下种植体骨界面应力分布特征。结果不同加载下,种植体周围骨应力主要集中在种植体颈部平台与皮质骨接触区,随植入深度加深,从牙槽嵴顶向下转移,减轻了牙槽嵴顶负荷。在植入牙槽嵴顶下1mm时最大Vonmise应力有效降低。斜向载荷下种植体周围骨最大Vonmise应力显著高于垂直载荷下的应力大小。结论临床中平台转换种植体植入时应将颈部平台置于牙槽嵴顶下皮质骨中。在Ⅳ类骨质中低于牙槽嵴顶1mm有利于减轻种植体颈部边缘牙槽骨负荷。

Objective To investigate the influence of placing depth of the implants with platform switching on the stress distribution in periimplant bone according to type Ⅳ bone area. To provide a reference for cinical application.Methods CT scanning technology and software such as Mimics10.01, Solidwork2007 and Ansys14.0 were applied to establish five finite element models consisting of type Ⅳ bone of anterior maxillary, implant with platform switching and superstructure and incisor crown based on five different insertion depth. The stresses distribution characteristics in periimplant bone under vetical 100 N and inclined 100 N loading were investigated. Results The periimplant bone stress is mainly concentrated in the contact area of the implant neck platform and the cortical bone, and shifted down with deeper placing lever. Burden of alveolar crestal is reduced. When the placing depth was 1mm below alveolar crest lever,the maximum von-mises stress was effectively reduced. Maximum von-mises stresses under inclined load were higher than those under vertical load. Conclusion It is recommended that implant neck platform should be located in the cortical bone. In type Ⅳ bone area, placed 1mm below alveolar crest lever can improve the stress distribution of marginal bone.