Reclaru L, Lerf R, Eschler P-Y, Blatter A, Meyer J-M
Groupe PX, PX Tech, Bldv des Eplature 46, La Chaux-de-Fonds 2304, Switzerland.
Biomaterials. 2003 Aug;24(18):3027-38. doi: 10.1016/s0142-9612(03)00145-5.
The corrosion behavior of titanium with vacuum plasma sprayed titanium coatings and with anodized surfaces, both with and without polymeric bone cement were evaluated. Electrochemical extraction tests were carried out with subsequent analysis of the electrolyte by ICP-MS in order to verify our hypothesis of the ionic permeability of the polymer cement. The complexity of the situation resides in the existence of two interfaces: electrolyte-polymer and polymer-metal. The surface preparation (treatment of the surface) plays an important role in the corrosion resistance of titanium. The electrochemical magnitudes that were examined reveal that the plasma spray surfaces have the lowest corrosion resistance. The cement, in spite of having reduced electrical conductivity in comparison to metal, is an ionic transporter, and therefore capable of participating in the corrosion process. In the present study, we observed in fact crevice corrosion at the metal-cement interface. In the case of plasma spray surfaces, a process of diffusion of titanium particles in the electrolyte could accompany the crevice corrosion. In this study, we have shown that there is a corrosion process at the surface of the titanium through the cement which has as a consequence on the one hand the formation of titanium cations and on the other hand the growth of a passive layer on the titanium. In conclusion, we identified two principal factors that influence the corrosion process: [1] the type of surface treatment for the titanium, and [2] the ionic conductivity of the cement. There is indeed ionic transport through the cement; as evidenced by the presence of titanium in the electrolyte solution (ICP-MS analysis) and chloride at the surface of the titanium sample (EDX analysis). We show that the polymer cement is an ionic conductor and participates in the corrosion of the embedded titanium. We cannot deduce from our results, however, whether the polymer itself possesses corrosive properties. Long-term experiments will be necessary to study the degradation behavior of the polymer cement.
对带有真空等离子喷涂钛涂层和阳极氧化表面的钛，在有和没有聚合物骨水泥的情况下的腐蚀行为进行了评估。进行了电化学萃取试验，并随后通过电感耦合等离子体质谱法对电解液进行分析，以验证我们关于聚合物骨水泥离子渗透性的假设。情况的复杂性在于存在两个界面：电解液-聚合物界面和聚合物-金属界面。表面处理（表面的处理）在钛的耐腐蚀性中起着重要作用。所检测的电化学参数表明，等离子喷涂表面的耐腐蚀性最低。尽管与金属相比水泥的电导率降低，但它是一种离子传输体，因此能够参与腐蚀过程。在本研究中，我们实际上观察到了金属-水泥界面处的缝隙腐蚀。在等离子喷涂表面的情况下，缝隙腐蚀可能伴随着钛颗粒在电解液中的扩散过程。在本研究中，我们已经表明，通过水泥在钛表面存在腐蚀过程，其结果一方面是钛阳离子的形成，另一方面是钛上钝化层的生长。总之，我们确定了影响腐蚀过程的两个主要因素：[1]钛的表面处理类型，以及[2]水泥的离子电导率。确实存在通过水泥的离子传输；电解液溶液中钛的存在（电感耦合等离子体质谱法分析）以及钛样品表面氯化物的存在（能量散射X射线光谱分析）证明了这一点。我们表明聚合物骨水泥是一种离子导体，并参与嵌入钛的腐蚀。然而，我们不能从我们的结果中推断出聚合物本身是否具有腐蚀性。需要进行长期实验来研究聚合物骨水泥的降解行为。
