Gönül Onur, Çicek Ahmet, Afat İbrahim Murat, Akdoğan Emine Tuna, Atalı Onur
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Marmara University, 34722 İstanbul, Turkey.
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, İstanbul Kent University, 34433 İstanbul, Turkey.
Life (Basel). 2022 Nov 23;12(12):1963. doi: 10.3390/life12121963.
The aim of this study is to examine the effect of unilaterally more posterior placement of implants (Straumann BLT 4.1 mm in diameter and 12 mm long) applied according to the all-on-four concept on the stress distribution on bone, implants, and other prosthetic components, using the finite element analysis method. Three scenarios were modelled: For Model 1 (M1), anterior implants were placed symmetrically perpendicular to the bone in the right and left lateral incisor region, while the necks of the posterior implants placed symmetrically in the second premolar region were angled at 30 degrees. For Model 2 (M2) the implant in the left second premolar region was placed to the first molar region unilaterally. For Model 3 (M3) the implant in the left lateral incisor region was placed to the canine region unilaterally. Vertical and oblique forces (100 N) were applied in the right first molar region. The von Mises and maximum (Pmax) and minimum (Pmin) principal stresses were obtained. The highest stress concentration on the cortical bone was observed in the second premolar region in all models when oblique forces were applied. M1 was highest (8.992 MPa) followed closely by M3 (8.780 MPa) and M2 was lowest (3.692 MPa). The highest stress concentration on the prosthetic parts was observed in this framework when oblique forces were applied. M2 was highest (621.43 MPa) followed by M3 (409.16 MPa) and the lowest was M1 (309.43 MPa). It is thought that placing the implant further posterior to first molar region may prevent the bone resorption that occurs with high stress around the crestal bone. However, increased stress on the implants and prosthetic parts may lead to failures.
本研究旨在采用有限元分析方法，研究根据全口四颗种植体理念，将种植体（直径4.1毫米、长12毫米的Straumann BLT）单侧更向后放置对骨、种植体及其他修复部件应力分布的影响。建立了三种模型：模型1（M1）中，前牙种植体对称垂直于右侧和左侧侧切牙区域的骨放置，而后牙种植体对称放置在第二前磨牙区域，其颈部呈30度角。模型2（M2）中，左侧第二前磨牙区域的种植体单侧放置到第一磨牙区域。模型3（M3）中，左侧侧切牙区域的种植体单侧放置到尖牙区域。在右侧第一磨牙区域施加垂直和斜向力（100牛）。获得了冯·米塞斯应力以及最大主应力（Pmax）和最小主应力（Pmin）。施加斜向力时，所有模型中皮质骨上的最高应力集中均出现在第二前磨牙区域。M1最高（8.992兆帕），紧随其后的是M3（8.780兆帕），M2最低（3.692兆帕）。施加斜向力时，该框架中修复部件上的最高应力集中被观察到。M2最高（621.43兆帕），其次是M3（409.16兆帕），最低的是M1（309.43兆帕）。据认为，将种植体进一步向后放置到第一磨牙区域之后，可能会防止牙槽嵴骨周围因高应力而发生的骨吸收。然而，种植体和修复部件上应力的增加可能会导致失败。
