Sabri Laith A, Hussein Falah A, Al-Zahawi Abdulsalam R, Abdulrahman Besaran Y, Salloomi Kareem N
Department of Mechatronics, Al-Khwarizmi College of Engineering, University of Baghdad, Iraq.
Department of Maxillofacial Surgery, School of Dentistry, University of Sulaimani, Iraq.
Indian J Dent Res. 2020 Mar-Apr;31(2):203-208. doi: 10.4103/ijdr.IJDR_510_18.
The ability of implant dentistry to be a successful alternative for edentulous patients has increased in the last decade. Clinical features such as osseointegration and stability, in addition to the endurance of the integration urged the researchers towards a better understanding of the design parameters that control long term success of the implants. It is therefore necessary to quantify the effect of changing implant design parameters on interface stress distribution within the maxilla bone.
A 3D-finite element study was conducted to investigate the effect of changing implant shape parameters (implant body design and implant thread depth) on stress distribution while insertion of the implant in two different regions of maxilla bone (anterior (type III bone) and posterior (type IV bone)). A 3D-CAD geometry of implant-maxilla bone was created through importing digitally visualized CT skull images of a human adult, and then converted into a workable solid body through using a collection of engineering software. Tapered and cylindrical implant models with three different implant V-shaped thread depths (0.25 mm, 0.35 mm, 0.45 mm) were threaded into maxilla bone to investigate the design parameters effect on the final stress status. The proposed implant was of commercial dimensions of 10 mm length and 4 mm in diameter. A vertical static load of 250N was directly applied to the center of the suprastructure of the implant for each model.
Evaluations were performed for stress distribution patterns and maximum equivalent Von Mises (EQV) stresses for implants in two regions of maxilla bone under 250N vertical static loading. The obtained results throughout this work showed that, for all models, the highest stresses were located at the crestal cortical bone around the implant neck. The von-Mises stress distribution patterns at different models were similar and higher peak von-Mises stresses of cortical bone were seen in tapered implant body compared to cylinder body in all models.
Within the restrictions of the current model, the results obtained can be applied clinically to select properly both implant thread depth and body shape design for a foreseeable success of implant therapy.
在过去十年中，种植牙成为无牙患者成功替代方案的能力有所提高。除了骨结合的持久性外，诸如骨整合和稳定性等临床特征促使研究人员更好地理解控制种植体长-term成功的设计参数。因此，有必要量化改变种植体设计参数对上颌骨内界面应力分布的影响。
进行了一项三维有限元研究，以调查在将种植体植入上颌骨的两个不同区域（前部（III型骨）和后部（IV型骨））时，改变种植体形状参数（种植体主体设计和种植体螺纹深度）对应力分布的影响。通过导入一名成年人类的数字化可视化CT颅骨图像，创建了种植体-上颌骨的三维CAD几何模型，然后使用一系列工程软件将其转换为可操作的实体。将具有三种不同种植体V形螺纹深度（0.25毫米、0.35毫米、0.45毫米）的锥形和圆柱形种植体模型拧入上颌骨，以研究设计参数对最终应力状态的影响。所提议的种植体具有10毫米长、4毫米直径的商业尺寸。对每个模型，将250N的垂直静载荷直接施加到种植体上部结构的中心。
对在250N垂直静载荷下上颌骨两个区域的种植体的应力分布模式和最大等效冯·米塞斯（EQV）应力进行了评估。在整个这项工作中获得的结果表明，对于所有模型，最高应力位于种植体颈部周围的牙槽嵴皮质骨处。在所有模型中，与圆柱体相比，锥形种植体主体中皮质骨的冯·米塞斯应力分布模式相似，且皮质骨的冯·米塞斯应力峰值更高。
在当前模型的限制范围内，所获得的结果可在临床上应用，以合理选择种植体螺纹深度和主体形状设计，从而使种植治疗获得可预见的成功。
