Lahoti Krishnakumar, Pathrabe Anup, Gade Jaykumar
Department of Prosthodontics and Implantology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital, Nagpur, Maharashtra, India.
Indian J Dent Res. 2016 Nov-Dec;27(6):597-601. doi: 10.4103/0970-9290.199587.
The purpose of this research was to compare stress distribution on the bone between single implant-retained and two-implant-retained mandibular overdentures using three-dimensional (3D) finite element analysis.
Two 3D finite element models were designed. The first model included single implant-supported mandibular overdenture placed in the midline of the mandible while the second model included two-implant-supported mandibular overdenture placed in the intra-foramen region, retained by ball attachment of the same diameter. The bone was modeled on the D2 bone depending on the classification given by Misch. A computed tomography scan of the mandible was used to model the bone by plotting the key points on the graph and generating the identical key points on the ANSYS Software (ANSYS, Inc., USA). The implant was modeled using appropriate dimensions as provided by the manufacturer. Stresses were calculated based on the von Mises criteria.
Stresses produced in the hard bone (HB) and soft bone (SB) were higher in single implant-retained mandibular overdenture while stresses produced around the denture as well as implant were higher in two-implant-retained mandibular overdenture.
Within the limitations of the study, it had been seen that stresses produced were the highest on HB and SB in single implant-retained mandibular overdenture while stresses produced across the denture as well as implant were the highest in two-implant-retained mandibular overdenture.
本研究的目的是使用三维（3D）有限元分析比较单颗种植体固位和两颗种植体固位的下颌覆盖义齿在骨上的应力分布。
设计了两个3D有限元模型。第一个模型包括放置在下颌骨中线的单颗种植体支持的下颌覆盖义齿，而第二个模型包括放置在孔内区域的两颗种植体支持的下颌覆盖义齿，通过相同直径的球附着体固位。根据Misch给出的分类，在D2型骨上对骨进行建模。通过在下颌骨的计算机断层扫描上绘制关键点并在美国ANSYS软件（ANSYS公司）上生成相同的关键点来对骨进行建模。种植体使用制造商提供的适当尺寸进行建模。基于冯·米塞斯准则计算应力。
单颗种植体固位的下颌覆盖义齿在硬骨（HB）和软骨（SB）中产生的应力较高，而两颗种植体固位的下颌覆盖义齿在义齿以及种植体周围产生的应力较高。
在本研究的局限性内，可以看出单颗种植体固位的下颌覆盖义齿在HB和SB上产生的应力最高，而两颗种植体固位的下颌覆盖义齿在整个义齿以及种植体上产生的应力最高。
