Han Xiang-Yong, Ju Ya-Qiong, Zhang Lin-Lin, Tian Zhi-Juan
Dental Implant Clinic, Shanghai Minhang District Dental Center. Shanghai 201107, China. E-mail:
Shanghai Kou Qiang Yi Xue. 2024 Aug;33(4):367-372.
To analyze the stress distribution of polyetheretherketone framework of implant-supported fixed maxillary prosthesis by three-dimensional finite element method.
Three dimensional finite element model of implant-supported fixed maxillary prosthesis was established. Polyetheretherketone as framework material, resin, zirconia, PEEK, baked plastic and lithium silicate were used to make crown prosthesis as experimental group, pure titanium and monolithic zirconia prosthesis model was used as control group. The feasibility of PEEK framework was analyzed by loading 150N axially and obliquely on the first molar, and the maximum compressive stress, minimum tensile stress and von Mises principal stress of the framework, crown, screw, implant, cortical and cancellous bone were measured and compared.
Under axially loading, the von Mises stress in the monolithic zirconia and lithium silicate crowns were 361 MPa and 295 MPa, while the stress in resin and PEEK crowns were 35 MPa and 37 MPa, respectively. The screw von Mises stress of the experimental group was 694-724 MPa, which was much higher than 61 MPa of the control group.The maximum and minimum stresses of the screw appeared in the resin crown and PEEK crown group. Under oblique loading,von Mises stress of the framework in the experimental group was lower than that in the control group, but the maximum stress appeared in the resin crown and PEEK crown. von Mises stresses of monolic zirconia and lithium disilicate crowns in the experimental group were higher than that of resin and PEEK crowns. von Mises stress of the implant in the experimental group was twice that of the control group. von Mises stress in screw of the experimental group was much higher than that of the control group, and the maximum stress was 22 times that of the control group. The stresses of cancellous bone and cortical bone in the experimental group were twice that of the control group, and the differences were larger than that under vertical loading.
In order to reduce the stress of crowns,resin or PEEK materials are preferred to be used as the crown prosthesis when PEEK was framework of implant-supported fixed maxillary prosthesis. Reducing the cantilever and lateral force may avoid excessive stress in screw.
采用三维有限元方法分析种植体支持的上颌固定修复体聚醚醚酮支架的应力分布。
建立种植体支持的上颌固定修复体三维有限元模型。以聚醚醚酮为支架材料，树脂、氧化锆、聚醚醚酮、烤塑和硅酸锂制作冠修复体作为实验组，纯钛和全瓷氧化锆修复体模型作为对照组。通过在第一磨牙上轴向和斜向加载150N分析聚醚醚酮支架的可行性，测量并比较支架、冠、螺钉、种植体、皮质骨和松质骨的最大压应力、最小拉应力和von Mises主应力。
轴向加载时，全瓷氧化锆和硅酸锂冠的von Mises应力分别为361MPa和295MPa，而树脂和聚醚醚酮冠的应力分别为35MPa和37MPa。实验组螺钉的von Mises应力为694 - 724MPa，远高于对照组的61MPa。螺钉的最大和最小应力出现在树脂冠和聚醚醚酮冠组。斜向加载时，实验组支架的von Mises应力低于对照组，但最大应力出现在树脂冠和聚醚醚酮冠。实验组全瓷氧化锆和二硅酸锂冠的von Mises应力高于树脂和聚醚醚酮冠。实验组种植体的von Mises应力是对照组的两倍。实验组螺钉的von Mises应力远高于对照组，最大应力是对照组的22倍。实验组松质骨和皮质骨的应力是对照组的两倍，且差异大于垂直加载时。
为降低冠的应力，当聚醚醚酮作为种植体支持的上颌固定修复体的支架时，树脂或聚醚醚酮材料优先用作冠修复体。减少悬臂和侧向力可避免螺钉出现过大应力。
