Almeida Paulo H T, Cacciacane Sergio H, França Fabiana M G
Department of Dental Surgery, São Leopoldo Mandic Institute and Dental Research Center, Campinas, SP, Brazil.
Ann Med Surg (Lond). 2018 Apr 21;30:22-27. doi: 10.1016/j.amsu.2018.04.029. eCollection 2018 Jun.
To make a comparative evaluation, by means of the finite element method, of the stress generated on supporting tissues and prosthetic system components, using zygomatic implants with the exteriorized and extramaxillary techniques, and different placement positions, associated either with inclined anterior implants, or those without inclination.
Eight (8) tridimensional models were created to represent the clinical situations being researched, using the dataset of scanned images of an edentulous model. The implants and prosthetic components were photographed on millimeter paper and inserted into Rhinoceros 3D modeling computer software. From the measurements made on the image, the virtual models were made. The application force was distributed on the occlusal surface of the working side of the left maxillary first molar, first and second premolars, and incisal regions of the central incisor, simulating the occlusal load during mastication, in a total of 150 N.
The extramaxillary technique presented considerable variation in increased tension on the prosthesis screws and bone tissue. In the exteriorized technique, the highest tension values occurred in the region of the ridge, and the lowest, on the zygomatic process; the absence of cantilever reduced the stress on bone tissue in almost all regions.
The exteriorized technique was shown to be more favorable to the distribution of stresses on the micro-unit screws and bone tissue, with the model with zygomatic implant placed in the region of the first molar and inclined anterior implant presenting the best results.
采用有限元方法，对使用颧骨种植体的外置技术和上颌外技术以及不同植入位置（与倾斜的前牙种植体或无倾斜的种植体相关）时，支撑组织和修复系统组件上产生的应力进行比较评估。
利用无牙颌模型的扫描图像数据集创建八（8）个三维模型，以代表所研究的临床情况。将种植体和修复组件在毫米纸上拍照，然后插入犀牛3D建模计算机软件中。根据图像上的测量结果制作虚拟模型。在左上颌第一磨牙、第一和第二前磨牙的工作侧咬合面以及中切牙的切缘区域施加作用力，模拟咀嚼过程中的咬合负荷，总共150 N。
上颌外技术在假体螺钉和骨组织上的张力增加方面呈现出相当大的差异。在外置技术中，最高张力值出现在牙槽嵴区域，最低值出现在颧骨突区域；悬臂的缺失几乎在所有区域都降低了骨组织上的应力。
结果表明，外置技术更有利于微单元螺钉和骨组织上应力的分布，颧骨种植体置于第一磨牙区域且前牙种植体倾斜的模型效果最佳。
