School of Dentistry, China Medical University and Hospital, Taichung, Taiwan.
J Periodontol. 2011 Feb;82(2):302-10. doi: 10.1902/jop.2010.100040. Epub 2010 Sep 1.
This study investigates the effect of depth of insertion in subcrestal cortical bone (SB) and thickness of connected cortical bone (CB) for a subcrestal implant placement on bone stress and strain using statistical analyses combined with experimental strain-gauge tests and numerical finite element (FE) simulations.
Three experimental, artificial jawbone models and 72 FE models were prepared for evaluation of bone strain and stress around various equicrestal and subcrestal implants. For in vitro tests, rosette strain gauges were used with a data acquisition system to measure bone strain on the bucco-lingual side. The maximum von Mises stresses in the bone were statistically analyzed by analysis of variance for FE models.
The experimental bone strains reduced significantly (22% to 49%) as the thickness of CB increased. FE analyses indicated that the suggested CB thickness for efficiently minimizing bone stress was 0.5 to 2.5 mm. The results for the depth of SB were not absolute because obvious stress reductions only presented at a certain range of depth (0.6 to 1.2 mm).
Within the limitations of this study, increasing the thickness of CB and maintaining the depth of SB within a limited range can provide the benefit of decreasing the stress and strain in surrounding bone for subcrestally placed implants.
本研究通过统计分析结合实验应变计测试和数值有限元（FE）模拟，研究了种植体在牙槽嵴下皮质骨（SB）中的植入深度和相连皮质骨（CB）厚度对骨应力和应变的影响。
制备了三个实验性人工下颌骨模型和 72 个 FE 模型，以评估各种等距和牙槽嵴下种植体周围的骨应变和骨应力。对于体外测试，使用带有数据采集系统的花键应变计测量颊舌侧的骨应变。通过对 FE 模型的方差分析，对最大 von Mises 骨应力进行了统计学分析。
随着 CB 厚度的增加，实验骨应变显著降低（22%至 49%）。FE 分析表明，为了有效最小化骨应力，建议的 CB 厚度为 0.5 至 2.5 毫米。SB 深度的结果并非绝对，因为仅在一定的深度范围内（0.6 至 1.2 毫米）才能明显降低应力。
在本研究的限制范围内，增加 CB 的厚度并将 SB 的深度保持在有限的范围内，可以为牙槽嵴下植入物提供减少周围骨的应力和应变的益处。
