Department of Dental Materials and Prosthodontics, Aracatuba School of Dentistry, Universidade Estadual Paulista, Araçatuba, SP,Brazil.
J Prosthodont. 2011 Jan;20(1):29-34. doi: 10.1111/j.1532-849X.2010.00656.x. Epub 2010 Nov 18.
To evaluate stress distribution in different horizontal mandibular arch formats restored by protocol-type prostheses using three-dimensional finite element analysis (3D-FEA).
A representative model (M) of a completely edentulous mandible restored with a prefabricated bar using four interforaminal implants was created using SolidWorks 2010 software (Inovart, São Paulo, Brazil) and analyzed by Ansys Workbench 10.0 (Swanson Analysis Inc., Houston, PA) to obtain the stress fields. Three mandibular arch sizes were considered for analysis, regular (M), small (MS), and large (ML). Three unilateral posterior loads (L) (150 N) were used: perpendicular to the prefabricated bar (L1); 30° oblique in a buccolingual direction (L2); 30° oblique in a lingual-buccal direction (L3). The maximum and minimum principal stresses (σ(max), σ(min)), the equivalent von Mises (σ(vM)), and the maximum principal strain (σ(max) ) were obtained for type I (M.I) and type II (M.II) cortical bones.
Tensile stress was more evident than compression stress in type I and II bone; however, type II bone showed lower stress values. The L2 condition showed highest values for all parameters (σ(vM), σ(max), σ(min), ɛ(max)). The σ(vM) was highest for the large and small mandibular arches.
The large arch model had a higher influence on σ(max) values than did the other formats, mainly for type I bone. Vertical and buccolingual loads showed considerable influence on both σ(max) and σ(min) stresses.
通过三维有限元分析（3D-FEA）评估使用协议型义齿修复的不同水平下颌弓形态的应力分布。
使用 SolidWorks 2010 软件（巴西圣保罗的 Inovart）创建一个具有代表性的完全无牙下颌模型（M），该模型使用四个跨牙槽嵴种植体修复预制杆，并使用 Ansys Workbench 10.0（Swanson Analysis Inc.，休斯顿，PA）进行分析，以获得应力场。考虑了三种下颌弓尺寸进行分析，即常规（M）、小（MS）和大（ML）。使用三种单侧后向载荷（L）（150 N）：垂直于预制杆（L1）；颊舌 30°斜向（L2）；30°舌颊向斜向（L3）。获得了 I 型（M.I）和 II 型（M.II）皮质骨的最大和最小主应力（σ(max)，σ(min)）、等效 von Mises（σ(vM)）和最大主应变（σ(max)）。
在 I 型和 II 型骨中，拉伸应力比压缩应力更为明显；然而，II 型骨的应力值较低。对于所有参数（σ(vM)、σ(max)、σ(min)、ε(max)），L2 条件下的应力值最高。大、小下颌弓的 σ(vM)值最高。
与其他格式相比，大弓模型对 σ(max)值的影响更大，主要是对 I 型骨。垂直和颊舌向载荷对 σ(max)和 σ(min)应力都有很大影响。
