van Oirschot Bart A J A, Meijer Gert J, Bronkhorst Ewald M, Närhi Timo, Jansen John A, van den Beucken Jeroen J J P
Department of Biomaterials, Radboudumc, Nijmegen, The Netherlands.
Department of Implantology and Periodontology, Radboudumc, Nijmegen, The Netherlands.
Clin Oral Implants Res. 2016 Feb;27(2):e57-67. doi: 10.1111/clr.12529. Epub 2014 Dec 8.
This in vivo study with implants installed in the goat iliac crest was performed to determine whether the biological and mechanical properties of the bone-to-implant interface are influenced by (i) the type of implant anchorage (i.e., mono- vs. bicortical placement), and (ii) the presence of a bioactive hydroxyapatite (HA) or composite HA/bioactive glass (BG) coatings.
A total of 96 titanium (Ti) implants w/- coatings (Ti, Ti-HA & Ti-HABG; n = 8) were mono- or bicortically placed in the iliac crest of eight goats. At installation and after 4 weeks, implant stability was determined using insertion and removal torque testing (ITQ & RTQ). The peri-implant bone response was histologically and histomorphometrically evaluated by means of bone-to-implant contact (BIC%) and bone area (BA%).
Monocortical implants demonstrated significantly lower RTQ values in comparison to ITQ values, whereas for bicortical implant placement RTQ and ITQ were similar. Further, mean RTQ values for monocortical implants were significantly lower in comparison to bicortical implants. Histomorphometrical evaluation demonstrated higher BIC% and BA% for bicortical implants compared to monocortical implants. For bicortical implants, BA% in the inner peri-implant region (0-500 μm) was significantly higher compared to the middle (500-1000 μm) and outer (1000-1500 μm) region. Also, a significant correlation was observed for monocortical implants between RTQ and BIC% and BA%. For surface modifications, no significant differences were found in ITQ and RTQ, for neither mono- nor bicortical implants. Histomorphometrically, HABG-coated implants demonstrated significantly higher BIC% compared to GAE surfaces for both mono- and bicortical implants. Bicortical HA-coated implants revealed significant higher BA% in the inner peri-implant region (0-500 μm) in comparison to bicortical GAE implants.
This study demonstrated that bicortical implant placement beneficially affects implant stability during the early phase of osseointegration. A significant correlation between removal torque and bone-to-implant contact and bone area for monocortical implants was observed, but not for bicortical implants. Therefore, histomorphometrical data should be interpreted with caution to predict the biomechanical implant fixation of bone implants over time. Regarding surface modifications, in the present implantation model, the addition of BG to an RF magnetron sputtered HA coating enhanced the biological behavior of the coating compared to grit-blasted/acid-etched implants.
本体内研究通过在山羊髂嵴植入种植体，以确定种植体与骨界面的生物学和力学性能是否受以下因素影响：（i）种植体锚固类型（即单皮质与双皮质植入），以及（ii）生物活性羟基磷灰石（HA）或复合HA/生物活性玻璃（BG）涂层的存在。
总共96枚带涂层的钛（Ti）种植体（Ti、Ti-HA和Ti-HABG；n = 8）单皮质或双皮质植入8只山羊的髂嵴。在植入时和4周后，通过插入和取出扭矩测试（ITQ和RTQ）确定种植体稳定性。通过种植体与骨接触（BIC%）和骨面积（BA%）对种植体周围骨反应进行组织学和组织形态计量学评估。
与ITQ值相比，单皮质种植体的RTQ值显著更低，而双皮质种植体植入时RTQ和ITQ相似。此外，单皮质种植体的平均RTQ值显著低于双皮质种植体。组织形态计量学评估显示，双皮质种植体的BIC%和BA%高于单皮质种植体。对于双皮质种植体，种植体内侧区域（0 - 500μm）的BA%显著高于中间区域（500 - 1000μm）和外侧区域（1000 - 1500μm）。此外，观察到单皮质种植体的RTQ与BIC%和BA%之间存在显著相关性。对于表面改性，单皮质和双皮质种植体的ITQ和RTQ均未发现显著差异。组织形态计量学显示，对于单皮质和双皮质种植体，HABG涂层种植体的BIC%均显著高于喷砂/酸蚀表面种植体。与双皮质GAE种植体相比，双皮质HA涂层种植体在种植体内侧区域（0 - 500μm）的BA%显著更高。
本研究表明，双皮质种植体植入在骨结合早期对种植体稳定性有有益影响。观察到单皮质种植体的取出扭矩与种植体与骨接触及骨面积之间存在显著相关性，但双皮质种植体未观察到。因此，在预测骨种植体随时间的生物力学固定时，应谨慎解释组织形态计量学数据。关于表面改性，在本植入模型中，与喷砂/酸蚀种植体相比，在射频磁控溅射HA涂层中添加BG可增强涂层的生物学性能。
