Meijer H J, Starmans F J, Steen W H, Bosman F
Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthetics, University Hospital Groningen, The Netherlands.
J Oral Rehabil. 1996 Nov;23(11):757-63. doi: 10.1046/j.1365-2842.1996.d01-185.x.
The design of dental superstructures influences the loading on dental implants and the deformation of the anterior interforaminal bone in an edentulous mandible. This deformation causes stress in the bone around the implants and may lead to bone resorption and loss of the implant. The stress distribution around dental implants in an edentulous mandible was calculated by means of a three-dimensional, finite-element model of the anterior part of the jaw. This model was built from data obtained from slices of a single human mandible and was provided with four endosseous implants in the interforaminal region. The implants were either connected with a bar or remained solitary. The solitary implants or the bars were loaded either uniformly or non-uniformly. In case of a non-uniform distribution, either the central bar or the central implants were loaded or the lateral bars or the lateral implants were loaded. The most extreme stresses in the bone were always located around the neck of the implant. In the case of the uniform distribution of the loading there were more or less equal extreme principal stresses around the central and lateral implants. If the load was not uniformly distributed on the superstructure then the implant that was nearest to the place of loading showed the highest stress concentration; with connected implants there was a reduction in the magnitude of the extreme principal stresses compared to solitary implants.
牙上部结构的设计会影响牙种植体上的负荷以及无牙下颌前孔间骨的变形。这种变形会在种植体周围的骨中产生应力，并可能导致骨吸收和种植体丧失。通过下颌前部的三维有限元模型计算无牙下颌中牙种植体周围的应力分布。该模型基于从单个人类下颌骨切片获得的数据构建，并在前孔间区域设置了四个骨内种植体。种植体要么通过杆连接，要么保持独立。独立种植体或杆承受均匀或非均匀负荷。在非均匀分布的情况下，要么中央杆或中央种植体承受负荷，要么外侧杆或外侧种植体承受负荷。骨中最极端的应力总是位于种植体颈部周围。在负荷均匀分布的情况下，中央和外侧种植体周围的极端主应力或多或少相等。如果负荷在牙上部结构上分布不均匀，那么最靠近负荷部位的种植体显示出最高的应力集中；与独立种植体相比，连接种植体的极端主应力大小有所降低。
