两种口腔镍铬合金离子析出的体外实验研究

目的 研究Heraenium S与TILITE P两种口腔镍铬合金在唾液pH值和成分变化时离子析出行为。方法 将两种合金试件在pH6墙正常唾液环境中浸泡一周，再用pH4的酸性及酸性加0．1％F^-的人工唾液处理两小时，之后回到正常唾液环境中浸泡一周，观察其在处理前、后镍离子的析出和表面理化状态的改变。结果 ①在正常唾液环境中HeraeniumS合金镍离子的析出量大于TILITEP合金；②pH降低和氟化物的加入增大了两种合金镍离子的析出量，其中TILITEP合金大于HeraeniumS合金；③在短暂的pH降低和加入氟化物后再回到正常唾液环境中，TILITEP合金的镍离子析出量大于HeraeniumS合金；并且在合金表面可以观察到形态学上的腐蚀破坏。结论 口腔镍铬合金的镍离子析出受到口腔环境动态变化的影响，TILITEP合金对环境改变的敏感性曼大。

Effects of salivary contents and pH on element released from Ni - Cr dental alloys

Objective To examine the effects of salivary contents and pH on elements released from Ni-Cr dental alloy Heraenium S and TILITE P in different pH and contents of saliva.Methods Eighteen specimens for each alloy were first immersed in pH 6.8 AS(represented the normal salivary environment in oral cavity)for one week.Then the specimens were treated with pH 4 AS and pH 4 AS containing 0.1% F-for two hours,respectively.The release of nickel ion was measured after the treatments with atomic absorption spectrophotometry.Changes of alloy surface were also observed with scanning electron microscope and X-ray photoelectron spectroscopy.Results The release of nickel ion from Heraenium S was higher than that from TILITE P in normal salivary environment.The release of nickel ion from both alloys was higher in saliva with lower pH and the presence of fluoride than in normal salivary environment.In saliva with lower pH and the presence of fluoride,the release of nickel ion from TILITE P was higher than from Heraenium S.After transient treated with lower pH and the presence of fluoride,the release of nickel ion from TILITE P became higher than that from Heraenium S in the normal saliva environment,and corrosion on the surface of TILITE P was also observed.Conclusion The release of nickel ion from Ni-Cr dental alloys may be affected by the dynamic oral environment and TILITE P appears to be more sensitive to environmental changes.