Rieger M R, Fareed K, Adams W K, Tanquist R A
University of Texas Medical Center, Dental Branch, Houston.
J Prosthet Dent. 1989 Feb;61(2):223-8. doi: 10.1016/0022-3913(89)90379-x.
Axisymmetric finite element models of three geometries were evaluated: a serrated solid with a 2-degree taper and a rectangular cross section; a cylindrical screw-type solid; and a finned solid with a 1 degree 9' taper and a circular cross section. Ten moduli of elasticity ranging from 0.348 to 74.96 psi x 10(6) were used for each geometry. Contour plots of the resulting Von Mises stresses were used to study the changing stress distribution patterns within the surrounding cortical bone. The results indicated that the serrated geometry led to high-stress concentrations at the tips of the bony ingrowth and near the neck of the implant. Low moduli of elasticity emphasized these concentrations. The nontapered screw-type geometry had high-stress concentrations at the base of the implant when high moduli were studied and at the neck of the implant when low moduli were studied. The conclusion of this study was that a tapered endosseous implant with a high elastic modulus would be most suitable for dental implantology. However, the design must not cause high-stress concentrations at the implant neck that commonly cause bone resorption.
一种是具有2度锥度和矩形横截面的锯齿状实体；一种是圆柱形螺旋型实体；还有一种是具有1度9分锥度和圆形横截面的带翅片实体。每种几何形状使用了10种弹性模量，范围从0.348到74.96磅力每平方英寸×10⁶。所得冯·米塞斯应力的等高线图用于研究周围皮质骨内应力分布模式的变化。结果表明，锯齿状几何形状在骨长入的尖端和植入物颈部附近导致高应力集中。低弹性模量会加剧这些集中现象。对于非锥形螺旋型几何形状，在研究高弹性模量时，植入物底部存在高应力集中；在研究低弹性模量时，植入物颈部存在高应力集中。本研究的结论是，具有高弹性模量的锥形骨内植入物最适合牙种植学。然而，该设计绝不能在通常会导致骨吸收的植入物颈部引起高应力集中。
