Sun Xin, Cheng Kangjie, Liu Yunfeng, Ke Sipeng, Zhang Wentao, Wang Linhong, Yang Fan
Department of Stomatology, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.
College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China.
Front Bioeng Biotechnol. 2023 Jun 16;11:1187504. doi: 10.3389/fbioe.2023.1187504. eCollection 2023.
The all-on-4 concept is widely used in clinical practice. However, the biomechanical changes following the alteration of anterior-posterior (AP) spread in all-on-4 implant-supported prostheses have not been extensively studied. Three-dimensional finite element analysis was used to compare the biomechanical behavior of all-on-4 and all-on-5 implant-supported prostheses with a change in anterior-posterior (AP) spread. A three-dimensional finite element analysis was performed on a geometrical mandible model containing 4 or 5 implants. Four different implant configurations were modeled by varying the angle of inclination of the distal implants (0°and 30°), including all-on-4a, all-on-4b, all-on-5a, and all-on-5b, and a 100 N force was successively applied to the anterior and unilateral posterior teeth to observe and analyze the differences in the biomechanical behavior of each model under the static influence at different position. Adding an anterior implant to the dental arch according to the all-on-4 concept with a distal 30° tilt angle implant exhibited the best biomechanical behavior. However, when the distal implant was implanted axially, there was no significant difference between the all-on-4 and all-on-5 groups. In the all-on-5 group, increasing the AP spread with tilted terminal implants showed better biomechanical behavior. It can be concluded that placing an additional implant in the midline of the atrophic edentulous mandible and increasing the AP spread might be beneficial in improving the biomechanical behavior of tilted distal implants.
“all-on-4”理念在临床实践中被广泛应用。然而，“all-on-4”种植支持式修复体前后（AP）间距改变后的生物力学变化尚未得到广泛研究。本研究采用三维有限元分析方法，比较“all-on-4”和“all-on-5”种植支持式修复体在前后（AP）间距改变时的生物力学行为。对包含4颗或5颗种植体的下颌骨几何模型进行三维有限元分析。通过改变远端种植体的倾斜角度（0°和30°）模拟四种不同的种植体配置，包括“all-on-4a”、“all-on-4b”、“all-on-5a”和“all-on-5b”，并先后对前牙和单侧后牙施加100 N的力，以观察和分析各模型在不同位置静态影响下生物力学行为的差异。根据“all-on-4”理念，在牙弓中添加一颗前牙种植体，同时远端种植体倾斜30°时，生物力学行为最佳。然而，当远端种植体轴向植入时，“all-on-4”组和“all-on-5”组之间没有显著差异。在“all-on-5”组中，增加倾斜末端种植体的AP间距显示出更好的生物力学行为。可以得出结论，在萎缩性无牙下颌骨中线处额外植入一颗种植体并增加AP间距，可能有助于改善倾斜远端种植体的生物力学行为。
