表没食子儿茶素没食子酸酯对镍铬合金电化学腐蚀后表面结构和性能的影响

The effect of epigallocatechin gallate(EGCG) on the surface properties of nickel-chromium dental casting alloys after electrochemical corrosion

目的:研究表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)对镍铬合金电化学腐蚀后表面结构和性能的影响。方法:采用体视显微镜和扫描电镜,观察经0 g/L和1.0 g/L EGCG人工唾液电化学腐蚀后镍铬合金的表面形貌,并运用光电子能谱仪分析经0 g/L和1.0 g/L EGCG人工唾液电化学腐蚀后镍铬合金的表面腐蚀产物。结果:经0 g/L和1.0 g/L EGCG人工唾液电化学腐蚀后,镍铬合金表面均有不同程度的腐蚀,在0 g/L EGCG人工唾液中,出现的点蚀坑直径较小,基本未影响合金表面的枝晶结构;而在1.0 g/L EGCG人工唾液中,镍铬合金表面发生了较为严重的腐蚀,点蚀坑直径较大,枝晶区间开始融合、变得模糊不清。此外,经0 g/L EGCG和1.0 g/L EGCG人工唾液电化学腐蚀后,镍铬合金表面溅射120 s后均检测到了O、Ni、Cr、Be、C及Mo元素,表面氧化物均主要为NiO和Cr2O3。与0 g/L EGCG人工唾液相比,镍铬合金在1.0 g/L EGCG人工唾液电化学腐蚀后表面O元素、NiO和Cr2O3的含量较低。结论:经EGCG人工唾液电化学腐蚀后,镍铬合金表面形貌和表面腐蚀产物结果一致,提示1.0 g/L EGCG促使镍铬合金表面耐腐蚀性能变差,表面腐蚀产物中氧化物含量也降低。

PURPOSE： To investigate the effect of epigallocatechin gallate（EGCG） on the surface properties of nickelchromium dental alloys after electrochemical corrosion. METHODS： The surface morphology and surface structure of nickel-chromium dental alloys were examined by stereomicroscope and scanning electron microscopy before and after electrochemical tests in 0 g/L and 1.0 g/L EGCG artificial saliva. The surface element component and chemical states of nickel-chromium dental alloys were analyzed by X-ray photoelectron spectrograph after electrochemical tests in 0 g/L and1.0 g/L EGCG artificial saliva. RESULTS： More serious corrosion happened on the surface of nickel-chromium alloy in1.0 g/L EGCG artificial saliva than in 0 g/L EGCG. The diameters of corrosion pits were smaller, and the dendrite structure of the alloy surface was not affected in 0 g/L EGCG. While the diameters of corrosion pits were larger, the dendritic interval of the alloy surface began to merge, and the dendrite structure was fuzzy in 1.0 g/L EGCG. In addition,the O, Ni, Cr, Be, C and Mo elements were detected on the surface of nickel-chromium alloys after sputtered for 120 s in0 g/L EGCG and 1.0 g/L EGCG artificial saliva after electrochemical corrosion, and the surface oxides were mainly NiO and Cr2O3. Compared with 0 g/L EGCG artificial saliva, the content of O, NiO and Cr2O3 were lower in 1.0 g/L EGCG.CONCLUSIONS： The results of surface morphology and the corrosion products both show that the corrosion resistance of nickel-chromium alloys become worse and the oxide content of corrosion products on the surface reduce in 1.0 g/L EGCG artificial saliva.