Lin Dong, Wen Zi-Heng, Guo Xiao-Ning, Zhang Yuqing
Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China.
School of Machine engineering and automation, Fuzhou University, Xueyuan Road No.2, Fuzhou, Fujian, China.
Clin Oral Investig. 2025 Apr 9;29(5):233. doi: 10.1007/s00784-025-06306-4.
Few studies have provided a detailed analysis of stress distribution on the components of multi-unit abutment (MUA)-implants complex, particularly the abutment screw and prosthetic screw, which are among the most fragile parts of the restoration. Our objective was to investigate the differences of stress distribution on the components of MUA-implants complex under varies loading conditions using finite element analysis.
We constructed MUA-implant complexes with different abutment angulations (0°, 17°, and 30°). A static force of 200 N was applied along the axis of the prosthetic abutment, accompanied by varying lateral forces (0 N, 30 N, and 100 N).
When subjected to a 200 N axial load, implants with a 30° angulated abutment experienced nearly 2.5 times the stress (1185 MPa) compared to straight abutments (437 MPa). The maximum stress of the straight MUA-implant was 8 times higher under a 100 N lateral force (2389 MPa) compared to that without lateral force. Prosthetic screws suffered higher stress concentration than the abutment screw and stress was mostly located near the first thread of the prosthetic screw.
There is a distinct stress distribution pattern between the prosthetic screw and abutment screw, with the former experiencing higher stress concentration than the latter.
The present study indicates that prosthetic screws are more vulnerable to mechanical complications and cautions should be raised to balance biting force to minimize the risks of mechanical complications in patients with angulated MUA-implants complex.
很少有研究对多单位基台（MUA）-种植体复合体各部件上的应力分布进行详细分析，尤其是基台螺钉和修复体螺钉，它们是修复体中最脆弱的部分。我们的目的是使用有限元分析研究不同加载条件下MUA-种植体复合体各部件上应力分布的差异。
我们构建了具有不同基台角度（0°、17°和30°）的MUA-种植体复合体。沿修复体基台轴线施加200 N的静力，并施加不同的侧向力（0 N、30 N和100 N）。
在200 N轴向载荷作用下，与直基台（437 MPa）相比，基台角度为30°的种植体承受的应力几乎是其2.5倍（1185 MPa）。在100 N侧向力作用下，直MUA-种植体的最大应力（2389 MPa）比无侧向力时高8倍。修复体螺钉比基台螺钉承受更高的应力集中，且应力大多位于修复体螺钉的第一螺纹附近。
修复体螺钉和基台螺钉之间存在明显的应力分布模式，前者承受的应力集中比后者更高。
本研究表明，修复体螺钉更容易出现机械并发症，对于有角度的MUA-种植体复合体患者，应注意平衡咬合力，以尽量降低机械并发症的风险。
