Ma Qian, Wu Feng-ming
Department of Prosthodontics, Nanjing Medical University, Nanjing 210029, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2011 Mar;46(3):172-6.
To evaluate the types and compositions of oxide films formed during porcelain-fused-to-metal (PFM) firing on three kinds of dental casting alloys, and to investigate the corrosion property of these alloys in Dulbecco's modification of Eagle's medium (DMEM) cell culture fluid, before and after PFM firing.
Specimens of three dental casting alloys (Ni-Cr, Co-Cr and Ni-Ti) before and after PFM firing were prepared, and were immersed in DMEM cell culture fluid. After 30 days, the type and concentration of released metal ions were measured using inductively coupled plasma atomic emission spectroscopy (ICP-AES). X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used for analysis of oxide film on the alloys. One way-ANOVA was adopted in data analysis.
The total amount of metal ions released from the three dental alloys was found to be highest in Ni-Cr alloy [(2.829 ± 0.694) mg/L], followed by Co-Cr [(2.120 ± 0.418) mg/L] and Ni-Ti alloy [(1.211 ± 0.101) mg/L]. The amount of Ni ions released from Ni-Cr alloys [(1.531 ± 0.392) mg/L] was higher than that from Ni-Ti alloys [(0.830 ± 0.052) mg/L]. The amount of Cr, Mo ions released from Co-Cr alloy [Cr: (0.048 ± 0.011) mg/L, Mo: (1.562 ± 0.333) mg/L] was higher than that from Ni-Cr alloy [Cr: (0.034 ± 0.002) mg/L, Mo: (1.264 ± 0.302) mg/L] and Ni-Ti alloy [Cr: (0.013 ± 0.006) mg/L, Mo: (0.151 ± 0.026) mg/L] (P < 0.05). After PFM firing, the total amount of metal irons released from the three dental alloys decreased [Ni-Cr: (0.861 ± 0.054) mg/L, Co-Cr: (0.695 ± 0.327) mg/L, Ni-Ti: (0.892 ± 0.115) mg/L] (P < 0.05). In addition, XPS showed increase of Cr(2)O(3) and Mo-Ni oxide on the surface of all the alloys after PFM firing.
The amount of ions released from Ni-Cr alloy was the highest among the three dental casting alloys, this means Ni-Cr alloy is prone to corrode. The PFM firing process changed the alloys' surface composition. Increased Ni, Cr and Mo were found in oxide film, and the increase in Cr(2)O(3) can improve the corrosion-resistance of alloys.
评估三种牙科铸造合金在烤瓷熔附金属（PFM）烧制过程中形成的氧化膜类型及成分，并研究这些合金在PFM烧制前后在杜氏改良伊格尔培养基（DMEM）细胞培养液中的腐蚀性能。
制备三种牙科铸造合金（镍铬合金、钴铬合金和镍钛合金）在PFM烧制前后的样本，并将其浸入DMEM细胞培养液中。30天后，使用电感耦合等离子体原子发射光谱法（ICP-AES）测量释放的金属离子的类型和浓度。采用X射线光电子能谱法（XPS）和扫描电子显微镜（SEM）分析合金上的氧化膜。数据分析采用单因素方差分析。
发现三种牙科合金释放的金属离子总量中，镍铬合金最高[（2.829±0.694）mg/L]，其次是钴铬合金[（2.120±0.418）mg/L]和镍钛合金[（1.211±0.101）mg/L]。镍铬合金释放的镍离子量[（1.531±0.392）mg/L]高于镍钛合金[（0.830±0.052）mg/L]。钴铬合金释放的铬、钼离子量[铬：（0.048±0.011）mg/L，钼：（1.562±0.333）mg/L]高于镍铬合金[铬：（0.034±0.002）mg/L，钼：（1.264±0.302）mg/L]和镍钛合金[铬：（0.013±0.006）mg/L，钼：（0.151±0.026）mg/L]（P<０.05）。PFM烧制后，三种牙科合金释放的金属离子总量减少[镍铬合金：（0.861±0.054）mg/L，钴铬合金：（0.695±0.327）mg/L，镍钛合金：（0.892±0.115）mg/L]（P<０.05）。此外，XPS显示PFM烧制后所有合金表面的Cr(2)O(3)和钼镍氧化物增加。
三种牙科铸造合金中，镍铬合金释放的离子量最高，这意味着镍铬合金易于腐蚀。PFM烧制过程改变了合金的表面成分。在氧化膜中发现镍、铬和钼增加，并且Cr(2)O(3)的增加可以提高合金的耐腐蚀性。
