HEALTH EFFECTS OF DENTAL AMALGAMS IN CHILDREN

描述：本研究设计为多点随机临床试验。 试验比较两组修复牙科材料，银汞合金和。 用于单面和双面修复体和不锈钢全冠的复合材料 用于更大的修复体。 概述了四个具体目标。(前三个与那些相似 在RFA中描述的，第四个是独特的。) 1.调查潜在的心理/行为、神经、 儿童的肾脏或免疫功能损害或功能障碍 归因于接触牙科汞合金修复体。 2.调查尿汞浓度的程度， 使用银汞合金和不使用银汞合金的儿童血液、头发和口腔中的物质有所不同。 修复术。3.调查水银浓度的变化 随着时间的推移，尿液、血液、头发和口腔中的物质，从 修复体的放置。 4.研究剂量与剂量之间的关系，以 汞合金表面，汞暴露的各种生物标志物和可能的 其功能以及由观察到的健康的存在定义的响应 效果。 大约1,000名6-8岁的讲英语的儿童参加 基准将被跟踪五年。其他入选标准包括 对于有三颗或三颗以上龋齿的儿童，事先没有银汞合金 填充物，没有临床证据表明存在心理，行为， 神经学、免疫抑制障碍或影响肾脏的疾病 功能，而且没有证据表明海鲜消费量很高。人口将会 从缅因州附属中心的临床中心招募 社区牙科健康和波士顿地区的四个地点。所有这些都是 诊所治疗有积压治疗需求的服务不足的人群。 所有儿童都将在这些诊所接受训练有素的牙医的牙科护理。 在研究方案中。在每个地点，在随机之前，儿童将被 按龋齿程度分层，需要3-4次或5次或5次以上修复。 主要的结果衡量标准是五年研究期间智商的平均变化。 句号。结果变量包括一系列神经心理学 每年重复最多的评估。肾功能将通过以下方式评估 尿液分析：尿卟啉图谱、γ-谷氨酰转肽酶和 白蛋白水平。汞暴露将通过确定数量来评估 汞合金表面，汞合金表面积，汞的释放率 使用Halbach、Skare和 以及尿液、血浆和头发中的汞含量。信息 关于其他协变量的信息将被收集，包括父母的智力， 社会经济状况，医疗和牙科信息，其他神经毒性 母亲在怀孕期间吸烟和饮酒等暴露， 和儿童血铅水平。血液样本将在基线和 六个月来测量无机汞和其他可能 神经心理测试结果令人困惑。四种尿汞测量方法 将在第一年收集，然后每年收集。 神经心理测试、头发取样和汞合金释放的测量 费率将按基准和每年执行。受试者保留率 预计在五年结束时将达到75%。

DESCRIPTION: This study is designed as a multi-site randomized clinical trial to compare two sets of restorative dental materials, amalgam vs. composite for one and two-surface restorations and stainless steel crowns for larger restorations. Four specific aims are outlined. (The first three are similar to those described in the RFA, and the fourth one is unique.) 1. To investigate the potential psychological/behavioral, neurological, renal or immunological impairments or dysfunction in children that can be attributed to exposure to dental amalgam restorations. 2. To investigate the degree to which mercury concentrations in urine, blood, hair, and in the mouth differ in children with and without amalgam restorations. 3. To investigate the change in mercury concentrations in the urine, blood, hair, and in the mouth over time, beginning with the placement of the restorations. 4. To investigate the relationship between dose, as measured by number of amalgam surfaces, various biomarkers of mercury exposure and possible functions thereof, and response defined by the presence of observed health effects. About 1,000 participating English-speaking children who are 6-8 years old at baseline will be followed for five years. Additional inclusion criteria are for children to have three or more carious teeth, have no prior amalgam fillings, no clinical evidence of existing psychological, behavioral, neurologic, immunosuppressive disorders or disorders affecting kidney function, and no evidence of high seafood consumption. The population will be recruited from clinical centers in Maine affiliated with the Center for Community Dental Health and four locations in the Boston area. All of these clinics treat underserved populations who have a backlog of treatment needs. All children will receive dental care at these clinics by dentists trained in study protocol. At each site, prior to randomization, children will be stratified by caries level, either needing 3-4 or 5 or more restorations. The primary outcome measure is mean change in IQ during the five-year study period. Outcome variables include a battery of neuropsychological assessments with most repeated annually. Renal function will be assessed by urinalysis of urinary porphyrin profiles, gamma-glutamyl transpeptidase, and albumin levels. Mercury exposure will be assessed by determining the number of amalgam surfaces, surface area of amalgam, the release rate of mercury vapor from amalgams using a procedure adapted by Halbach, and Skare and Engquist, and mercury levels in urine, plasma, and scalp hair. Information about other covariates will be collected including parental intelligence, socioeconomic status, medical and dental information, other neurotoxic exposures such as maternal smoking and alcohol consumption during pregnancy, and child blood lead level. Blood samples will be collected at baseline and six months to measure inorganic mercury and other heavy metals that may confound neuropsychological test results. Four urinary mercury measurements will be collected during the first year, and then annually. Neuropsychological tests, hair sampling, and measurement of amalgam release rates will be conducted at baseline and annually. A subject retention rate of 75% at the end of five-years is anticipated.