镍铬合金烤瓷冠修复6个月及1年后血清镍铬元素含量变化:与健康对照者比较

背景：镍、铬虽人体必需元素，但其浓度过高将对人体产生许多不良影响，因此用于修复牙齿镍铬合金材料的生物安生性值得重视。目的：观察镍铬合金烤瓷冠修复6个月及1年后血清中镍铬元素含量的变化，并与健康对照者比较探讨镍铬合金长期存在于口腔中的安全性。设计、时间和地点：病例对照观察，于2006—01/2007-12在河北北方学院附属第一医院完成。对象：选择2006—01/12在河北北方学院附属第一医院口腔修复科就诊的60例上颌前牙有3颗行镍铬合金烤瓷冠修复的患者为实验组，男28例，女32例．平均40岁，均无其他金属充填物和修复体者。以60名同期到院健康体检者为对照组。男30例，女30例，平均39岁。方法：无菌抽取对照组健康者及实验组患者修复后0．5年，1年空腹静脉血，采用石墨炉原子吸收光谱法测定血清中镍、铬元素的含量。主要观察指标：实验组与对照组血清镍、铬元素含量变化。结果：纳入镍铬合金烤瓷冠修复患者60例及健康对照者60名均进入结果分析。实验组上颌前牙修复后0．5年血清镍含量与对照组比较差异无显著性意义（P〉0．05），修复后1年血清镍含量明显高于对照组（P〈0．05）。实验组修复后0．5及1年血清铬含量与对照组比较，差异无显著性意义（P〉0．05）。结论：上颌前牙行镍铬合金烤瓷冠修复后在口腔环境中释放一定的镍、铬。血清镍含量随修复时间延长有增高趋势，但量很微小，在人体生物安全范围内，是否会随修复时间延长而持续增加，需要长期随访评定。

Changes of serum nickel and chromium content at 6 months and 1 year after porcelain-fused-to-nichrome crown restoration: A comparison with healthy controls

BACKGROUND: Although nickel and chromium are essential elements of human body, over high concentration of them will produce many adverse effects to human body, therefore biological safety of nichrome material for dental restoration deserves attention.OBJECTIVE: To observe the changes of nickel and chromium content at 6 months and 1 year after porcelain-fused-to-nichrome crown restoration, and compare to healthy controls to investigate the long-term safety of nichorme in oral cavity.DESIGN, TIME AND SETTING: A case-control observation was performed between January 2006 and December 2007 at the First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei Province, China.PARTICIPANTS: Sixty patients who visited Department of Stomatology, the First Affiliated Hospital of Hebei North University, between January and December 2006 were included in test group, including 28 male, 32 female, the mean age was 40 years. Each of them had 3 anterior maxillary teeth restored by porcelain-fused-to-nichrome crowns, without other metal fillings or protheses. Sixty healthy cases visited the hospital at the same time were used as control, including 30 male, 30 female, the mean ages was 39 years.METHODS: Fasting venous blood of participants in two groups was harvested sterilely at 6 months and 1 year after test group restoration, serum nickel and chromium content were determined using graphite furnace atomic absorption spectrometry.MAIN OUTCOME MEASURES: ① Serum nickel content changes in test and control group. ②Serum chromium content changes in test and control groupRESULTS: All cases were involved in result analysis. ① Serum nickel content changes in test and control group: At 6 months postrestoration, there was no significant difference in serum nickel content between test group and control group (P>0.05). At 1 year after restoration, serum nickel content of test group was significantly higher than that of control group (P<0.05). ② Serum chromium content changes in test and control group: There was no significant difference in chromium content between test and control group at 6 months and 1 year after test group restoration (P>0.05).CONCLUSION: Nickel and chromium released from porcelain-fused-to-nichrome crowns after restoration under oral environment, serum nickel content had an increasing tendency with the prolongation of restoration time, but in small quantity and within biosafety range, to identify whether the increasing tendency will increased continuously with the prolongation of restoration time needs long-term follow-up.