HEALTH EFFECTS OF DENTAL AMALGAMS IN CHILDREN

描述：本研究设计为一项多中心随机临床试验， 试验比较两套牙科修复材料，汞合金与 用于单面和双面修复和不锈钢冠的复合材料 对于更大的扩张。 提出了四个具体目标。 (The前三个类似于 在RFA中描述，第四个是唯一的。） 1. 为了调查潜在的心理/行为，神经， 儿童的肾或免疫损伤或功能障碍， 这是由于暴露于牙科汞合金置换。 2. 为了调查尿中汞浓度， 血液、头发和口腔中的汞合金与未使用汞合金的儿童不同 道歉 3. 为了调查汞浓度的变化， 尿液，血液，头发，随着时间的推移，在嘴里，开始与 的位置。 4. 为了研究剂量之间的关系，如通过数量测量的 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状况定义的反应 方面的影响. 约有1，000名6至8岁的英语儿童参加， 基线将被跟踪五年。 其他入选标准为 对于有三颗或三颗以上龋牙的儿童， 填充物，没有临床证据表明现有的心理，行为， 神经系统、免疫抑制性疾病或影响肾脏的疾病 功能，没有证据表明高海鲜消费。 人口将 从附属于中心的缅因州临床中心招募 社区牙科健康和波士顿地区的四个地点。 所有这些 诊所为那些没有得到充分服务的人提供治疗，这些人有大量的治疗需求。 所有儿童都将在这些诊所接受受过培训的牙医的牙科护理 在研究方案中。 在每个研究中心，在随机化之前，儿童将 根据龋齿水平分层，需要3-4次或5次或更多次治疗。 主要的结果测量是在五年的研究中智商的平均变化 期 结果变量包括一组神经心理学的 每年重复评估的次数最多。 将通过以下方式评估肾功能： 尿卟啉谱、γ-谷氨酰转肽酶和 白蛋白水平 汞暴露将通过确定 汞合金表面积、汞的释放速率 使用Halbach和斯卡雷改编的程序， 尿液、血浆和头发中的汞含量。 信息 将收集关于其他协变量的信息，包括父母的智力， 社会经济地位、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， 和儿童血铅水平。 将在基线时采集血样， 六个月来测量无机汞和其他重金属， 混淆了神经心理学测试结果 四项尿汞测量 将在第一年收集，然后每年收集。 神经心理学测试、毛发取样和汞合金释放测量 将在基线和每年进行费率调查。 受试者留存率 预计在五年内达到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.