Bassi-Junior Luiz, Oliveira de Souza Silva Rafael, Dias Dos Santos Victor Hugo, da Rocha Lourenço Abner, Trevizoli Paulo Vinicius, Gaêta-Araujo Hugo, Queiroz Polyane Mazucatto, Gottardo Vilmar Divanir
Department of Dentistry, Area of Implantology, Ingá Center University, Maringa, Brazil.
Department of Mechanical Engineering, Ingá University Center, Maringa, Brazil.
J Oral Biol Craniofac Res. 2021 Jul-Sep;11(3):438-441. doi: 10.1016/j.jobcr.2021.05.007. Epub 2021 May 15.
In some clinical situations, the installation of four or more dental implants may be infeasible. Therefore, the installation of protocol-type prostheses with only three implants may be necessary. The mechanical failures can hinder the success of the rehabilitation treatment.
To evaluate and compare the mechanical stress of the metallic prosthetic bar when installed over protocol-type prostheses of three and four implants, and to evaluate the stress on the dental implants.
Two three-dimensional human jaw models were created. In one model, four dental implants (P4) were designed and in the other model three dental implants (P3) were designed. In both models, according to the arrangement of the dental implants, prosthetic bars were designed. In a finite element analysis software, compressive forces were applied to the ends of both prosthetic bars, simulating the force application during mastication. Tension and stress dissipation were analyzed on the prosthetic bar and dental implants.
Both P4 and P3 protocol-type prostheses supported the force efficiently without breaking the bar or the implants. Force dissipation along the bar was more homogeneous in the P3 prosthetic bar than in P4. In addition, P3 implants received a higher concentration of stress in relation to P4 implants.
Prosthetic bars and dental implants withstand the stress of load application in both four and three implant protocol-type prostheses. Three-implants protocol showed more satisfactory force dissipation than the four-implant protocol.
在某些临床情况下，植入四颗或更多颗牙种植体可能不可行。因此，可能需要安装仅带有三颗种植体的标准型假体。机械故障可能会阻碍修复治疗的成功。
评估并比较金属修复杆安装在三颗和四颗种植体的标准型假体上时的机械应力，并评估牙种植体上的应力。
创建了两个三维人体颌骨模型。在一个模型中设计了四颗牙种植体（P4），在另一个模型中设计了三颗牙种植体（P3）。在两个模型中，根据牙种植体的排列设计了修复杆。在有限元分析软件中，向两个修复杆的末端施加压缩力，模拟咀嚼过程中的力施加情况。分析了修复杆和牙种植体上的张力和应力消散情况。
P4和P3标准型假体均能有效支撑力，不会使杆或种植体断裂。与P4相比，P3修复杆上沿杆的力消散更均匀。此外，与P4种植体相比，P3种植体承受的应力集中程度更高。
修复杆和牙种植体在四颗和三颗种植体标准型假体中均能承受加载应力。三颗种植体方案在力消散方面比四颗种植体方案更令人满意。
