Berdouses E, Vaidyanathan T K, Dastane A, Weisel C, Houpt M, Shey Z
Department of Prosthodontics and Biomaterials, UMDNJ-NJ Dental School, Newark 07103, USA.
J Dent Res. 1995 May;74(5):1185-93. doi: 10.1177/00220345950740050701.
The release of mercury vapor from class I amalgam restorations prepared in human molar teeth was studied during chewing simulations in an artificial mouth of a bi-axial servo-hydraulic mechanical test system. So that the total mercury released from the restoration over a fixed time could be determined, a closed chamber surrounded the envelope of chewing motion. In addition, the influence of sampling frequency on mercury release was corrected by the use of different sampling frequencies over a fixed time interval of mercury release measurement and extrapolation to zero sampling time. Thus, a combination of a closed environment and an extrapolation method to determine the mercury release under continuous sampling was used to determine the mercury released under normal breathing conditions. The measured mercury release rate data were used to calculate the potential daily mercury dose in a patient due to a single amalgam restoration, following the method previously outlined by Berglund. The mercury release from both a conventional and a high-copper amalgam was evaluated at different age intervals after the restoration was placed in the teeth. The results show that while the age of the amalgam and the amalgam type influence the extent of mercury release during the initial non-steady-state conditions, the steady-state value of mercury daily dose due to a single amalgam filling is 0.03 micrograms/day, which is well below the calculated threshold-limiting value (TLV) of 82.29 micrograms/day considered dangerous for occupational exposure in the United States.
在双轴伺服液压机械测试系统的人工口腔中进行咀嚼模拟时，研究了人类磨牙制备的I类汞合金修复体中汞蒸气的释放情况。为了确定修复体在固定时间内释放的总汞量，在咀嚼运动范围内设置了一个封闭腔室。此外，通过在汞释放测量的固定时间间隔内使用不同的采样频率并外推到零采样时间，校正了采样频率对汞释放的影响。因此，采用封闭环境和外推法相结合的方式，在连续采样条件下确定汞释放量，以测定正常呼吸条件下的汞释放量。按照Berglund之前概述的方法，利用测得的汞释放速率数据计算患者因单一汞合金修复体而潜在的每日汞摄入量。在将修复体植入牙齿后的不同年龄间隔，评估了传统汞合金和高铜汞合金的汞释放情况。结果表明，虽然汞合金的使用年限和类型会影响初始非稳态条件下的汞释放程度，但单一汞合金填充物的每日汞摄入量稳态值为0.03微克/天，远低于美国认为对职业暴露有危险的82.29微克/天的计算阈限值（TLV）。
