Biological & Medical Research Department, King Faisal Specialist Hospital & Research Centre, PO Box: 3354, Riyadh 11211, Saudi Arabia.
Sci Total Environ. 2011 Jul 15;409(16):3003-15. doi: 10.1016/j.scitotenv.2011.04.047. Epub 2011 May 20.
The risks and benefits of using mercury (Hg) in dental amalgam have long been debated. This study was designed to estimate Hg body burden and its association with dental amalgam fillings in 182 children (ages: 5-15 years) living in Taif City. Hg was measured in urine (UHg), hair (HHg) and toenails (NHg) by the Atomic Absorption Spectrophotometer with Vapor Generator Accessory system. Urinary Hg levels were calculated as both micrograms per gram creatinine (μg/g creatinine) and micrograms per liter (μg/L). We found that children with amalgam fillings (N=106) had significantly higher UHg-C levels than children without (N=76), with means of 3.763 μg/g creatinine versus 3.457 μg/g creatinine, respectively (P=0.019). The results were similar for UHg (P=0.01). A similar pattern was also seen for HHg, with means of 0.614 μg/g (N=97) for children with amalgam versus 0.242 μg/g (N=74) for those without amalgam fillings (P=0). Although the mean NHg was higher in children without amalgam (0.222 μg/g, N=61) versus those with (0.163 μg/g, N=101), the relationship was not significant (P=0.069). After adjusting for many confounders, the multiple logistic regression model revealed that the levels of UHg-C and HHg were 2.047 and 5.396 times higher, respectively, in children with dental amalgam compared to those without (P<0.01). In contrast, a significant inverse relationship was seen between NHg levels and dental amalgam fillings (P=0.003). Despite the controversy surrounding the health impact of dental amalgam, this study showed some evidence that amalgam-associated Hg exposure might be related with symptoms of oral health, such as aphthous ulcer, white patches, and a burning-mouth sensation. Further studies are needed to reproduce these findings. The present study showed that significant numbers of children with or without amalgam had Hg levels exceeding the acceptable reference limits. The detrimental neurobehavioral and/or nephrotoxic effects of such an increased Hg on children should be a cause of concern, and further investigation is warranted. Our results are alarming and indicate an urgent need for biomonitoring and assessment of exposure. Changes in dental practices involving amalgam, especially for children, are highly recommended in order to avoid unnecessary exposure to Hg.
长期以来，人们一直在争论在牙科汞合金中使用汞（Hg）的风险和益处。本研究旨在估计 182 名居住在塔伊夫市的儿童（年龄：5-15 岁）体内的 Hg 负荷及其与牙科汞合金填充物的关系。通过原子吸收分光光度计与蒸气发生附件系统测量尿（UHg）、头发（HHg）和指甲（NHg）中的 Hg。尿汞水平分别以每克肌酐微克（μg/g 肌酐）和每升微克（μg/L）计算。我们发现，有汞合金填充物的儿童（N=106）的 UHg-C 水平明显高于没有填充物的儿童（N=76），分别为 3.763μg/g 肌酐和 3.457μg/g 肌酐（P=0.019）。UHg 的结果也相似（P=0.01）。HHg 也呈现出类似的模式，有汞合金填充物的儿童的均值为 0.614μg/g（N=97），而没有汞合金填充物的儿童的均值为 0.242μg/g（N=74）（P=0）。尽管没有汞合金填充物的儿童的 NHg 平均值较高（0.222μg/g，N=61），但与有填充物的儿童相比（0.163μg/g，N=101），这种关系并不显著（P=0.069）。在调整了许多混杂因素后，多元逻辑回归模型显示，与没有汞合金填充物的儿童相比，有牙科汞合金填充物的儿童的 UHg-C 和 HHg 水平分别高 2.047 倍和 5.396 倍（P<0.01）。相比之下，NHg 水平与牙科汞合金填充物之间呈显著负相关（P=0.003）。尽管围绕牙科汞合金的健康影响存在争议，但本研究表明，汞合金相关 Hg 暴露可能与口腔健康症状有关，如口疮性溃疡、白斑和口腔烧灼感。需要进一步的研究来复制这些发现。本研究表明，有或没有汞合金的儿童中有相当数量的儿童 Hg 水平超过了可接受的参考限值。这种 Hg 增加对儿童的神经行为和/或肾毒性影响应引起关注，需要进一步调查。我们的研究结果令人震惊，表明迫切需要进行生物监测和暴露评估。为了避免不必要的 Hg 暴露，强烈建议改变涉及汞合金的牙科实践，尤其是针对儿童。
