Lee Joon-Seok, Lim Young-Jun
a Department of Prosthodontics and Dental Research Institute , School of Dentistry, Dankook University , Cheonan , Republic of Korea.
Comput Methods Biomech Biomed Engin. 2013;16(11):1143-9. doi: 10.1080/10255842.2012.654780. Epub 2012 Mar 8.
Lower survival rates were observed for the implant placed in the anterior maxilla. The purpose of this study was to investigate the influence of different implant lengths on the stress distribution around osseointegrated implants under a static loading condition in the anterior maxilla using a three-dimensional finite element analysis. The diameter of 4.0 mm external type implants of different lengths (8.5 mm, 10.0 mm, 11.5 mm, 13.0 mm, 15.0 mm) was used in this study. The anterior maxilla was assumed to be D3 bone quality. All the material was assumed to be homogenous, isotropic and linearly elastic. The implant-bone interface was constructed using a rigid element for simulating the osseointegrated condition. Then, 176 N of static force was applied on the middle of the palatoincisal line angle of the abutment at a 120°angle to the long axis of abutment. The von Mises stress value was measured with an interval of 0.25 mm along the bone-implant interface. Incremental increase in implant length causes a gradual reduction of maximum and average von Mises stress at the labial portion within the implant. In the bone, higher stress was concentrated within cortical bone area and more distributed at the labial cortex, while cancellous bone showed relatively low stress concentration and even distribution. An increase in implant length reduced stress gradients at the cortical peri-implant region. Implant length affects the mechanisms of load transmission to the osseointegrated implant. On the basis of this study the biomechanical stress-based performance of implants placed in the anterior maxilla improves when using longer implants.
在上颌前部植入的种植体观察到较低的存活率。本研究的目的是使用三维有限元分析，研究在静态加载条件下，不同种植体长度对上颌前部骨结合种植体周围应力分布的影响。本研究使用了不同长度（8.5毫米、10.0毫米、11.5毫米、13.0毫米、15.0毫米）的4.0毫米外径种植体。上颌前部假定为D3骨质。所有材料假定为均质、各向同性和线弹性。种植体-骨界面采用刚性单元构建以模拟骨结合状态。然后，在基台腭切缘线角的中点，以与基台长轴呈120°角的方向施加176 N的静力。沿骨-种植体界面以0.25毫米的间隔测量冯·米塞斯应力值。种植体长度的增加会导致种植体内唇侧部分的最大和平均冯·米塞斯应力逐渐降低。在骨中，较高的应力集中在皮质骨区域，且更多分布在唇侧皮质，而松质骨显示出相对较低的应力集中且分布均匀。种植体长度的增加降低了种植体周围皮质区域的应力梯度。种植体长度影响载荷传递至骨结合种植体的机制。基于本研究，在上颌前部植入种植体时，使用更长的种植体可改善基于生物力学应力的性能。
