Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Technicka 5, 16628 Prague 6, Czech Republic.
Biomed Mater. 2010 Oct;5(5):054108. doi: 10.1088/1748-6041/5/5/054108. Epub 2010 Sep 28.
Nowadays, a wide range of materials for human implants is used. To reach the required properties of implants, coatings are applied in some cases. This contribution is focused on the corrosion properties of TiN and ZrN layers on cp-titanium (commercially pure titanium) under environment modelling conditions in an oral cavity. Measurements were done in artificial saliva and a physiological solution unbuffered and buffered to a pH value of 4.2 with the addition of fluoride ions up to 4000 ppm. Standard corrosion electrochemical techniques were applied. Both types of layers were stable in both model saliva and physiological solution with non-adjusted pH. The decrease in pH to 4.2 resulted in a minor decrease of corrosion resistance in all cases, but polarization resistance was still in the order of 10(5) Ω cm². An important change in a specimens' behaviour was noticed in the presence of fluoride ions. TiN was stable in the highest concentration of fluorides used. The ZrN layers were destabilized in an environment containing a few hundred ppm of fluoride ions. As for TiN, the decisive factor is the influence of porosity; the corrosion resistance of ZrN is limited. From the corrosion point of view, the application of the TiN-based barrier layers in dental implantology is more advisable than the use of ZrN, provided that the application of a barrier is inevitable.
如今，人们广泛使用各种材料来制作人体植入物。在某些情况下，为了达到植入物的所需性能，会在材料表面涂覆涂层。本研究专注于模拟口腔环境中，TiN 和 ZrN 层在商用纯钛（cp-titanium）上的腐蚀性能。实验在人工唾液和未缓冲的生理溶液以及缓冲至 pH 值为 4.2 的生理溶液中进行，缓冲液中添加了氟离子，浓度最高可达 4000 ppm。采用标准腐蚀电化学技术进行测量。在未调节 pH 值的两种模型溶液中，这两种类型的涂层都具有稳定性。将 pH 值降低至 4.2 会导致所有情况下的腐蚀阻力略有下降，但极化电阻仍处于 10(5) Ω cm²的量级。在存在氟离子的情况下，发现试件行为发生了重要变化。TiN 在使用的氟化物浓度最高的情况下仍保持稳定。含几百 ppm 氟离子的环境会使 ZrN 层不稳定。对于 TiN，决定性因素是其孔隙率的影响；ZrN 的耐腐蚀性受到限制。从腐蚀的角度来看，在牙科植入物领域应用基于 TiN 的阻挡层比应用 ZrN 更可取，前提是必须应用阻挡层。
