Chen Fengshan, Terada Kazuto, Hanada Kooji, Saito Isao
Division of Orthodontics, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
Angle Orthod. 2005 Jul;75(4):593-601. doi: 10.1043/0003-3219(2005)75[593:AEOAPO]2.0.CO;2.
The purpose of this study was to compare the anchorage effect of the osseointegrated implant with different fixation types using finite element analysis. Three fixation types were investigated. fixation type 1: implant neck in the oral-palatal cortical bone and implant tip in the cancellous bone; fixation type 2: implant neck in the oral-palatal cortical bone and implant tip in the nasal-palatal cortical bone; fixation type 3: implant neck in the oral-palatal cortical bone and implant tip projecting into the nasal cavity. Three finite element models were constructed. Each consisted of two maxillary second premolars, their associated periodontal ligament (PDL), alveolar bones, palatal bone, palatal implant, and a transpalatal arch. Another model without an implant was used to compare with the previous models. The horizontal force (mesial five N, palatal one N) was loaded at the buccal bracket of each second premolar. The stress was calculated in the PDL and implant surrounding bone. The result showed that the palatal implant could significantly reduce von Mises stress (maximum von Mises stress was reduced 30%) and evenly distribute stress in the PDL. The stress magnitude and distribution in the PDL was almost the same in the three implant models. These results suggest that different implant fixation types have almost the same anchorage effects.
本研究的目的是使用有限元分析比较不同固定类型的骨整合种植体的支抗效果。研究了三种固定类型。固定类型1：种植体颈部位于口腔-腭侧皮质骨，种植体尖端位于松质骨；固定类型2：种植体颈部位于口腔-腭侧皮质骨，种植体尖端位于鼻-腭侧皮质骨；固定类型3：种植体颈部位于口腔-腭侧皮质骨，种植体尖端伸入鼻腔。构建了三个有限元模型。每个模型均由两颗上颌第二前磨牙、其相关的牙周膜（PDL）、牙槽骨、腭骨、腭部种植体和腭弓组成。另一个没有种植体的模型用于与之前的模型进行比较。在每颗第二前磨牙的颊面托槽处施加水平力（近中5N，腭侧1N）。计算牙周膜和种植体周围骨中的应力。结果表明，腭部种植体可显著降低冯·米塞斯应力（最大冯·米塞斯应力降低30%），并使牙周膜中的应力均匀分布。三种种植体模型中牙周膜的应力大小和分布几乎相同。这些结果表明，不同的种植体固定类型具有几乎相同的支抗效果。
