Chehroudi B, McDonnell D, Brunette D M
Department of Oral Biology, University of British Columbia, Vancouver, Canada.
J Biomed Mater Res. 1997 Mar 5;34(3):279-90. doi: 10.1002/(sici)1097-4636(19970305)34:3<279::aid-jbm2>3.0.co;2-h.
Surface topography varies widely among commercially available orthopedic and dental implants. While it is generally accepted that the surface topography of an implant influences the formation of bone and affects its performance, few systematic studies have dealt with this important feature. Quantification of the mineralized tissue at the implant interface has typically been attempted using histologic methods or conventional radiographic procedures. However, histologic methods are often technically demanding and time consuming, whereas conventional radiographic procedures lack resolution and sensitivity to identify small areas of mineralization. The objective of this study was to study systematically the effects of micromachined surfaces on bone formation by applying digital radiographic techniques to identify and quantify mineralized tissue. Titanium-coated epoxy replicas of 19 different micromachined grooved or pitted surfaces that ranged between 30 and 120 microns deep, as well as smooth control surfaces, were implanted percutaneously and fixed to the parietal bone of rats. After 8 weeks the implants and attached tissue were removed and processed for light and electron microscopy. A total of 316 implant surfaces were processed, radiographed using conventional and digital techniques, and sectioned for histologic observations. The area of the bonelike tissue and its density were calculated using National Institutes of Health Image software. Mineralization was frequently noted at the interface of some types of micromachined surface but rarely on smooth surfaces. The presence of bone in histologic sections and areas identified as bone through digital radiography and image processing correlated strongly. The frequency of bonelike foci formation decreased as the depth of the grooves increased. In contrast, mineralization occurred more frequently as the depth of the pit increased. In addition, bonelike foci were oriented along the long axis of the grooves. It is thus feasible that the bonelike tissue is shaped, directed, or engineered to a predetermined configuration which is dictated by the surface topography. This study indicated that surface topography influences the frequency as well as the amount of bone deposited adjacent to implants, and mineralized product can be guided by the surface topography. Moreover, digital radiography and image processing can be used reliably to identify and quantify mineralized tissue at the implant interface.
市售的骨科和牙科植入物的表面形貌差异很大。虽然人们普遍认为植入物的表面形貌会影响骨的形成并影响其性能，但很少有系统的研究涉及这一重要特征。通常尝试使用组织学方法或传统的放射学程序来量化植入物界面处的矿化组织。然而，组织学方法在技术上往往要求很高且耗时，而传统的放射学程序缺乏识别小面积矿化的分辨率和灵敏度。本研究的目的是通过应用数字放射技术来识别和量化矿化组织，系统地研究微加工表面对骨形成的影响。将19种不同的微加工沟槽或凹坑表面（深度在30至120微米之间）以及光滑对照表面的钛涂层环氧树脂复制品经皮植入并固定到大鼠的顶骨上。8周后，取出植入物和附着组织，进行光镜和电镜处理。总共对316个植入物表面进行了处理，使用传统和数字技术进行放射照相，并切片进行组织学观察。使用美国国立卫生研究院图像软件计算骨样组织的面积及其密度。在某些类型的微加工表面的界面处经常观察到矿化，但在光滑表面上很少观察到。组织学切片中骨的存在与通过数字放射照相和图像处理确定为骨的区域密切相关。随着沟槽深度的增加，骨样病灶形成的频率降低。相比之下，随着凹坑深度的增加，矿化发生得更频繁。此外，骨样病灶沿沟槽的长轴排列。因此，骨样组织有可能被塑造、引导或设计成由表面形貌决定的预定构型。这项研究表明，表面形貌会影响植入物附近骨沉积的频率和数量，矿化产物可以由表面形貌引导。此外，数字放射照相和图像处理可以可靠地用于识别和量化植入物界面处的矿化组织。
