de Andrade Camila Lima, Carvalho Marco Aurélio, Del Bel Cury Altair Antoninha, Sotto-Maior Bruno Salles
Int J Oral Maxillofac Implants. 2016 Jul-Aug;31(4):e92-7. doi: 10.11607/jomi.4133.
Dental implant macrogeometry parameters, such as the prosthetic connection and implant body shape, can influence the biomechanical behavior of the restoration. Using tridimensional finite element analysis (3D-FEA), this study evaluated the biomechanical behavior of two implant macrodesign parameters (prosthetic connection and implant body shape) in low-quality bone.
Four groups were obtained by the combination of external hexagon and Morse taper connections, and cylindrical and conical body shapes. Implants (4ø × 10-mm) with a microthread collar and triangular thread shape received a single abutment and monolithic zirconia crown on the maxillary first molar. Bone was constructed on the basis of cross-sectional images of the posterior human maxilla obtained by cone beam computed tomography. A 200-N axial loading was distributed on five points of the occlusal surface. Data were acquired as shear stress (τmax, in megapascals) and strain (εmax, in micrometers) in the cortical and trabecular bone.
The external hexagon groups generated higher shear stress/strain values compared with Morse taper groups in the cortical bone, regardless of implant body shape. In the trabecular bone, the highest τmax and εmax values were observed in the Morse taper conical implant group (6.94 MPa and 21.926 × 10⁻⁴ μm, respectively), and the lowest values were observed in the external hexagon cylindrical implant group (4.47 MPa and 9.3155 × 10⁻⁴ μm, respectively).
The magnitudes of shear stress and strain in the peri-implant region of low-quality bone was lower with the use of Morse taper connection and cylindrical implants compared with external hexagon connection and conical implants.
牙种植体的宏观几何参数，如修复体连接和种植体主体形状，会影响修复体的生物力学行为。本研究采用三维有限元分析（3D-FEA）评估了两种种植体宏观设计参数（修复体连接和种植体主体形状）在低质量骨中的生物力学行为。
通过外六角和莫氏锥度连接以及圆柱形和圆锥形主体形状的组合得到四组。带有微螺纹颈部和三角形螺纹形状的种植体（4ø×10毫米）在上颌第一磨牙上接受单个基台和整体式氧化锆冠。根据锥束计算机断层扫描获得的人类上颌后部横截面图像构建骨组织。在咬合面的五个点上施加200 N的轴向载荷。采集的数据为皮质骨和松质骨中的剪应力（τmax，单位为兆帕）和应变（εmax，单位为微米）。
无论种植体主体形状如何，皮质骨中外六角组产生的剪应力/应变值均高于莫氏锥度组。在松质骨中，莫氏锥度圆锥形种植体组观察到最高的τmax和εmax值（分别为6.94 MPa和21.926×10⁻⁴μm），而外六角圆柱形种植体组观察到最低值（分别为4.47 MPa和9.3155×10⁻⁴μm）。
与外六角连接和圆锥形种植体相比，使用莫氏锥度连接和圆柱形种植体时，低质量骨种植体周围区域的剪应力和应变幅度较低。
