Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Australia.
J Prosthodont Res. 2017 Oct;61(4):393-402. doi: 10.1016/j.jpor.2016.12.010. Epub 2017 Jan 18.
This study combines clinical investigation with finite element (FE) analysis to explore the effects of buccal bone thickness (BBT) on the morphological changes of buccal bone induced by the loaded implant.
One specific patient who had undergone an implant treatment in the anterior maxilla and experienced the buccal bone resorption on the implant was studied. Morphological changes of the bone were measured through a series of cone-beam computed tomography (CT) scans. A three-dimensional heterogeneous nonlinear FE model was constructed based on the CT images of this patient, and the in-vivo BBT changes are correlated to the FE in-silico mechanobiological stimuli; namely, von Mises equivalent stress, equivalent strain, and strain energy density. The anterior incisory bone region of this model was then varied systematically to simulate five different BBTs (0.5, 1.0, 1.5, 2.0, and 2.5mm), and the optimal BBT was inversely determined to minimize the risk of resorption.
Significant changes in BBTs were observed clinically after 6 month loading on the implant. The pattern of bone resorption fell into a strong correlation with the distribution of mechanobiological stimuli onsite. The initial BBT appeared to play a critical role in distributing mechanobiological stimuli, thereby determining subsequent variation in BBT. A minimum initial thickness of 1.5mm might be suggested to reduce bone resorption.
This study revealed that the initial BBT can significantly affect mechanobiological responses, which consequentially determines the bone remodeling process. A sufficient initial BBT is considered essential to assure a long-term stability of implant treatment.
本研究通过临床研究与有限元(FE)分析相结合,探讨颊侧骨厚度(BBT)对负载种植体引起颊侧骨形态变化的影响。
对一名在前上颌接受种植治疗并在种植体上发生颊侧骨吸收的特定患者进行研究。通过一系列锥形束 CT(CBCT)扫描测量骨的形态变化。基于该患者的 CT 图像构建了一个三维非均质非线性 FE 模型,并将体内 BBT 变化与 FE 体内生物力学刺激相关联,即 von Mises 等效应力、等效应变和应变能密度。然后,系统地改变该模型的前切牙骨区域,模拟五个不同的 BBT(0.5、1.0、1.5、2.0 和 2.5mm),并反演确定最佳 BBT,以最小化吸收风险。
在种植体负载 6 个月后,临床上观察到 BBT 发生显著变化。骨吸收的模式与现场生物力学刺激的分布呈强相关性。初始 BBT 似乎在分布生物力学刺激方面起着关键作用,从而决定了随后 BBT 的变化。建议初始 BBT 的最小厚度为 1.5mm 以减少骨吸收。
本研究表明,初始 BBT 可显著影响生物力学反应,从而决定骨重塑过程。足够的初始 BBT 被认为是确保种植体治疗长期稳定性的关键。