Department of Oral Implantology and Regenerative Dental Medicine, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Int J Oral Maxillofac Surg. 2011 Feb;40(2):200-6. doi: 10.1016/j.ijom.2010.10.002. Epub 2010 Dec 4.
This study investigated the biomechanical effects of crestal bone osteoplasty and flattening procedures carried out in edentulous knife-edge ridges to restore bone width before implant placement on the virtually placed implants using finite element methods. Three-dimensional models representing a knife-edged alveolar bone with two different crestal cortical bone thicknesses (1.6mm, thin group; 3.2mm, thick group) were created. Gradual crestal bone osteoplasty with 0.5mm height intervals was simulated. Cylindrical implants with abutments and crowns were constructed and subjected to oblique loads. Maximum stress was observed at the cervical region around the implant neck. Different osteoplasty levels showed different stress values and distributions. Highest compressive stress was observed in the flat models (60.8 MPa and 98.3 MPa in thick and thin groups, respectively), lowest values were observed when osteoplasty was limited to the sharp edge (36.8 MPa and 38.9 MPa in thick and thin groups, respectively). The results suggested that eliminating the sharp configuration in knife-edge ridges improved stress and strain outcomes, but flattening the alveolar crest and/or uncovering the cancellous bone resulted in a marked increase in compressive stress and strain values in the peri-implant bone that may influence the longevity of implants placed in these ridges.
本研究采用有限元方法，研究了在无牙刃状牙槽嵴上进行牙槽骨顶骨成形和平整手术，以恢复种植体放置前的骨宽度对虚拟放置的种植体的生物力学影响。建立了具有两种不同牙槽嵴皮质骨厚度（1.6mm，薄组；3.2mm，厚组）的刃状牙槽骨的三维模型。模拟了高度间隔为 0.5mm 的逐渐牙槽骨顶骨成形。构建了带有基台和牙冠的圆柱形种植体，并施加倾斜载荷。观察到最大应力出现在种植体颈部周围的颈部区域。不同的骨成形水平表现出不同的应力值和分布。在平模型中观察到最高的压缩应力（厚组和薄组分别为 60.8MPa 和 98.3MPa），在限制在锐缘的骨成形时观察到最低的应力（厚组和薄组分别为 36.8MPa 和 38.9MPa）。结果表明，消除刃状嵴的锐利形态可以改善种植体周围骨的应力和应变结果，但使牙槽嵴变平和平整以及/或暴露松质骨会导致种植体周围骨的压缩应力和应变值显著增加，这可能会影响放置在这些嵴上的种植体的使用寿命。
