Alvarez-Arenal Angel, Gonzalez-Gonzalez Ignacio, deLlanos-Lanchares Hector, Brizuela-Velasco Aritza, Martin-Fernandez Elena, Ellacuria-Echebarria Joseba
1 Department of Prosthodontics and Occlusion, School of Dentistry, University of Oviedo, Spain.
2 Department of Oral Stomatology I, Faculty of Medicine and Dentistry, University of Basque Country, Bilbao, Spain.
J Oral Implantol. 2017 Dec;43(6):419-428. doi: 10.1563/aaid-joi-D-17-00170. Epub 2017 Oct 3.
The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.
本研究的目的是根据种植体位置和不同加载条件，评估和比较下颌双种植体覆盖义齿种植体周围的骨应力。设计了四个模拟下颌双种植体覆盖义齿和Locator附着系统的三维有限元模型。种植体位于侧切牙、尖牙、第二前磨牙和交叉种植体水平。施加了150 N不同位置的单侧和双侧垂直载荷，以及与中线载荷组合时的40 N载荷。对种植体周围骨和加载条件的模型之间，以数字方式生成、颜色编码并比较了冯·米塞斯应力数据。单侧加载时，在所有4个模型中，与无载荷侧相比，载荷侧记录的种植体周围骨应力值要高得多，而双侧咬合加载时，两侧的应力分布相似。在所有模型中，后牙单侧加载显示出最高应力，随着载荷向近中施加，应力降低。一般来说，种植体位于前磨牙水平的模型中，种植体周围骨的生物力学环境最佳。在交叉种植体模型中，载荷侧极大地改变了生物力学环境。总体而言，无论载荷施加在哪里，第二前磨牙水平种植体的覆盖义齿都应是首选设计。咬合加载应用部位会影响种植体周围的骨应力。双侧咬合加载使种植体周围骨应力对称分布，而单侧加载无论种植体位于何处，都会使载荷侧的应力大幅增加。
