Department of Pediatric Dentistry, School of Dental Medicine, Ahvaz Jundishapur University of Medical Sciences, PO Box T: 61357-15794, Ahvaz, Iran.
Department of Dental Anatomy, Dental Faculty, Azad University of Medical Sciences, Tehran, Iran.
Biol Trace Elem Res. 2019 Jan;187(1):65-73. doi: 10.1007/s12011-018-1376-0. Epub 2018 May 23.
Nickel and chromium existing in stainless-steel crowns (SSCs, used in pediatric dentistry) might be cytotoxic and allergenic. However, no in vivo studies have examined their salivary levels in children using SSCs, or in young children without SSCs. Also, the effect of acidity on metal ion release has not yet been evaluated in any previous in vivo studies in the whole literature. Therefore, this preliminary before-after clinical trial was conducted. Salivary nickel/chromium levels of 30 children before and after 2 months of placement of SSCs were measured using atomic absorption spectrophotometry. Salivary pH was measured with a digital pH meter. The effects of treatment, pH, number of SSCs, gender, and age on salivary ions were analyzed statistically (α = 0.05, β = 0.15). Salivary nickel concentrations increased from 4.9010 ± 4.7390 to 5.6320 ± 4.7210 μg/L (P = 0.000, paired t test). Chromium increased from 0.3273 ± 0.5214 to 0.4199 ± 0.6404 μg/L (P = 0.016). Saliva pH increased from 6.81 ± 0.52 to 7.04 ± 0.47 (P = 0.000). Ion levels were not correlated with pH (P > 0.14), except chromium in the follow-up (rho = - 0.435, P = 0.016). Nickel increase (but not chromium increase) was correlated with pH increase (rho = 0.367, P = 0.046). Age was only correlated with baseline chromium (rho = 0.373, P = 0.042). Being male was associated with baseline/follow-up nickel levels (P ≤ 0.030). SSC number was not correlated with ions or pH (P > 0.36). It was shown for the first time that SSCs might increase salivary nickel and chromium concentrations and reduce saliva acidity. Nickel increase might be in line with pH elevation. The raised pH might be associated with reduced chromium release. Boys might have higher nickel levels than might girls, with or without SSCs.
不锈钢冠（用于儿童牙科）中的镍和铬可能具有细胞毒性和致敏性。然而，目前尚无研究使用不锈钢冠的儿童或无不锈钢冠的幼儿体内唾液中这些金属的水平。此外，在整个文献中，以前的体内研究都没有评估酸度对金属离子释放的影响。因此，进行了这项初步的前后对照临床试验。采用原子吸收分光光度法测量 30 名儿童在放置不锈钢冠后 2 个月内的唾液镍/铬水平。使用数字 pH 计测量唾液 pH 值。统计分析了治疗、pH 值、不锈钢冠数量、性别和年龄对唾液离子的影响（α = 0.05，β = 0.15）。唾液镍浓度从 4.9010 ± 4.7390 增加到 5.6320 ± 4.7210μg/L（P = 0.000，配对 t 检验）。铬从 0.3273 ± 0.5214 增加到 0.4199 ± 0.6404μg/L（P = 0.016）。唾液 pH 值从 6.81 ± 0.52 增加到 7.04 ± 0.47（P = 0.000）。除了随访时的铬（rho = - 0.435，P = 0.016）外，离子水平与 pH 值无关（P > 0.14）。镍的增加（而非铬的增加）与 pH 值的增加相关（rho = 0.367，P = 0.046）。年龄仅与基线铬相关（rho = 0.373，P = 0.042）。男性与基线/随访时的镍水平相关（P ≤ 0.030）。不锈钢冠数量与离子或 pH 值无关（P > 0.36）。这是首次表明不锈钢冠可能会增加唾液中的镍和铬浓度并降低唾液酸度。镍的增加可能与 pH 值升高有关。升高的 pH 值可能与铬释放减少有关。有或没有不锈钢冠的男孩的镍水平可能高于女孩。
