Sadek Hatem S, Anany Noha M, Diab Al-Hassan, El-Anwar Mohamed I, Alhotan Abdulaziz, Aldesoki Mostafa, Bourauel Christoph, Elshazly Tarek M
Oral Technology, Dental School, University Hospital Bonn, Bonn, Germany.
Department of Operative Dentistry, Faculty of Dentistry, Ain shams University, Cairo, Egypt.
Int Dent J. 2025 Jun;75(3):1913-1920. doi: 10.1016/j.identj.2025.01.014. Epub 2025 Feb 11.
To assess the biomechanical performance of cantilevered 2-unit implant-supported prostheses with zirconia and polyetherketoneketone (PEKK) under 3 loading conditions.
A cone beam computer tomography (CBCT) scan of an edentulous mandible was segmented using Mimics software and refined in 3-Matic software to create trabecular and cortical bone structures. Implant CAD files were integrated using SolidWorks software, generating 4 models with varying implant positions: M1 (first premolar implant supporting a second premolar), M2 (second premolar implant supporting a first premolar), M3 (second premolar implant supporting a first molar), and M4 (first molar implant supporting a second premolar). Prostheses were constructed from zirconia or PEKK. Finite element analysis (FEA) in ANSYS software simulated static loading: vertical (100 N) and oblique (30° and 45°, 50 N). von Mises stress and total deformation were analyzed.
Vertical loading showed the highest von Mises stress at cantilever connectors, with M3 displaying the highest cortical bone stress (117 MPa). Zirconia models had slightly higher prosthetic stress, while PEKK models exhibited greater implant and cortical bone stress. Oblique loading caused higher stress in implants and prostheses but remained below yield limits. Maximum deformation was under 25 micrometers for the implant and bone, and 65 micrometers for the prosthesis.
Single implants can support 2-unit cantilevered prostheses when additional implants are unfeasible. The location of the cantilever has minimal impact compared to its size, as a larger cantilevered part increases stress. Zirconia better resists bending forces and reduces implant stress compared to PEKK.
This study guides prosthodontists in designing 2-unit implant-supported prostheses, emphasizing that multiple implants optimize stress distribution, and that zirconia is preferable for cantilevered designs.
评估氧化锆和聚醚酮酮（PEKK）悬臂式2单位种植体支持修复体在3种加载条件下的生物力学性能。
使用Mimics软件对无牙下颌骨的锥形束计算机断层扫描（CBCT）进行分割，并在3-Matic软件中进行细化，以创建小梁和皮质骨结构。使用SolidWorks软件整合种植体CAD文件，生成4种不同种植体位置的模型：M1（第一前磨牙种植体支持第二前磨牙）、M2（第二前磨牙种植体支持第一前磨牙）、M3（第二前磨牙种植体支持第一磨牙）和M4（第一磨牙种植体支持第二前磨牙）。修复体由氧化锆或PEKK制成。在ANSYS软件中进行有限元分析（FEA），模拟静态加载：垂直（100 N）和倾斜（30°和45°，50 N）。分析von Mises应力和总变形。
垂直加载时，悬臂连接部位的von Mises应力最高，M3的皮质骨应力最高（117 MPa）。氧化锆模型的修复体应力略高，而PEKK模型的种植体和皮质骨应力更大。倾斜加载导致种植体和修复体中的应力更高，但仍低于屈服极限。种植体和骨的最大变形小于25微米，修复体的最大变形为65微米。
在无法增加种植体的情况下，单个种植体可以支持2单位悬臂式修复体。与悬臂大小相比，悬臂位置的影响最小，因为较大的悬臂部分会增加应力。与PEKK相比，氧化锆更能抵抗弯曲力并降低种植体应力。
本研究为口腔修复医生设计2单位种植体支持修复体提供了指导，强调多个种植体可优化应力分布，悬臂式设计中氧化锆更可取。
