Endowed Chair of Oral Technology, Rheinische Friedrich-Wilhelms University, Welschnonnenstr. 17, 53111 Bonn, Germany.
Med Eng Phys. 2012 Sep;34(7):817-25. doi: 10.1016/j.medengphy.2011.09.023. Epub 2011 Oct 12.
The aim of the present study was to investigate experimentally and numerically the influence of a fine threaded- against a roughened-cervical region of immediately loaded dental implants in combination with straight and 20°-angled abutments on the implant primary stability. A total of 30 implants were inserted in bovine rib-segments, 14 cervically roughened implants and 16 implants with fine cervical threads. Each implant system received two abutments, straight and 20°-angled. Implant displacements and rotations were measured using a biomechanical measurement system. Subsequently, eight samples were selected for geometrical reconstruction and numerical investigation of stress and strain distributions in the bone by means of the finite element method. Experimentally, both implant systems showed similar behaviour with the straight abutments concerning displacements and rotations. However, fine threaded implants showed much less displacement and rotation against roughened implants when angled abutments were considered. Numerically, stresses were within 35-45 MPa in the cortical bone for both implant systems. The strains showed highest values within the spongious bone with the roughened implants connected to angled abutments. The results indicate that implants with fine cervical threads could be recommended in particular with angled abutments. The outcomes of this study are currently confirmed by long-term clinical investigations.
本研究旨在实验和数值研究即刻加载的牙科种植体颈部粗糙区与精细螺纹区对种植体初期稳定性的影响，同时结合直型和 20°角基台。总共将 30 个种植体植入牛肋骨段，其中 14 个颈部粗糙种植体和 16 个颈部精细螺纹种植体。每个种植体系统都有直型和 20°角两种基台。使用生物力学测量系统测量种植体的位移和旋转。然后，选择了 8 个样本进行几何重建和数值研究，通过有限元方法研究骨中的应力和应变分布。实验中，直基台情况下，两种种植体系统的位移和旋转表现相似，但考虑到角度基台时，精细螺纹种植体的位移和旋转明显小于粗糙种植体。数值研究中，两种种植体系统的皮质骨内的应力都在 35-45MPa 之间。应变值在粗糙种植体与角度基台连接的多孔骨内最大。研究结果表明，精细螺纹种植体特别适合与角度基台一起使用。本研究的结果目前正在通过长期临床研究得到证实。
