Rieger M R, Adams W K, Kinzel G L, Brose M O
University of Texas Medical Center, Dental Branch, Houston.
J Prosthet Dent. 1989 Jun;61(6):717-22. doi: 10.1016/s0022-3913(89)80049-6.
Three endosseous post-type implant 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. Each implant geometry was analyzed with 10 different moduli of elasticity. Stress contour plots were used to identify which implant material was best suited to each implant geometry. Careful examination of all of the contour plots showed that, for all geometries, increasing the material stiffness transmitted more of the occlusal load to the apical bone. These plots further suggested that an implant material can be too stiff as the punching stresses increase at the apex of the implant. Of the three endosseous implants analyzed, only the finned solid type seemed to be made of the proper material, titanium alloy. The screw-type implant, made of sapphire, should be made of aluminum or possibly titanium. The serrated implant, made of polycrystalline alumina, was too stiff. An implant's elastic behavior is not the only governing factor. An implant's geometry seems to be the determining factor in properly distributing stresses from the implant to the bone.
一种是带有2度锥度和矩形横截面的锯齿状实心体，一种是圆柱形螺旋型实心体，还有一种是带有1度9分锥度和圆形横截面的带翅实心体。每种种植体几何形状都采用10种不同的弹性模量进行分析。应力等高线图用于确定哪种种植体材料最适合每种种植体几何形状。对所有等高线图的仔细检查表明，对于所有几何形状，增加材料刚度会将更多的咬合负荷传递到根尖骨。这些图还进一步表明，随着种植体根尖处的冲压应力增加，种植体材料可能会过硬。在所分析的三种骨内种植体中，只有带翅实心体类型似乎采用了合适的材料，即钛合金。由蓝宝石制成的螺旋型种植体应由铝或可能由钛制成。由多晶氧化铝制成的锯齿状种植体太硬。种植体的弹性行为不是唯一的决定因素。种植体的几何形状似乎是将种植体应力正确分布到骨组织中的决定因素。
