Objectives

BPA release from composites on the short term has been reported in several in-vitro and in-vivo studies. However, it remains unclear whether these materials also leach BPA on the long term. Even though composites may release various (BPA-based) methacrylate monomers up to one year, quantitative data about BPA have not been reported due to the lack of a sensitive method to accurately quantify low levels of BPA. In this context, the aim of the study was to quantify the one-year release of BPA with an optimized analytical method.

Methods

Composite disks (n = 6, 6 mm diameter and 2 mm height) from four commercial materials (G-ӕnial Posterior, Venus, Ceram.x mono and Filtek Supreme XTE) were immersed in 1 mL of water or ethanol as extraction solvent and stored in the dark at 37 °C. The extraction solvent was renewed weekly for a period of 52 weeks. Samples were derivatized with pyridine-3-sulfonyl chloride before analysis with ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

Results

Derivatizing BPA increased the sensitivity of the analytical method and allowed accurate quantification of very low levels of BPA (i.e. 0.78 pmol BPA). BPA eluted continuously in ethanol from all four tested composites over a period of one year. BPA elution was clearly higher when ethanol was used as extraction solution. In water, BPA eluted could be detected up to one year, but levels could not be accurately quantified anymore after several weeks.

Significance

Composites can be considered as a potential long-term source of BPA, and thus should not be neglected when assessing the overall exposure to endocrine disrupting chemicals.

中文翻译：

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从牙科复合材料中长期洗脱双酚 A

目标

一些体外和体内研究报告了复合材料短期内 BPA 的释放。然而，从长远来看，这些材料是否也会浸出 BPA 尚不清楚。尽管复合材料可能会在长达一年的时间内释放各种（基于 BPA 的）甲基丙烯酸酯单体，但由于缺乏准确量化低水平 BPA 的灵敏方法，尚未报告有关 BPA 的定量数据。在这种情况下，该研究的目的是使用优化的分析方法量化 BPA 的一年释放量。

方法

将来自四种商业材料（G-ӕnial 后部、Venus、Ceram.x mono 和 Filtek Supreme XTE）的复合圆盘（n = 6、6 mm 直径和 2 mm 高度）浸入 1 mL 水或乙醇作为提取溶剂中并储存在 37 °C 的黑暗中。萃取溶剂每周更换一次，持续 52 周。在使用超压液相色谱串联质谱 (UPLC-MS/MS) 进行分析之前，先用吡啶-3-磺酰氯对样品进行衍生化处理。

结果

BPA 的衍生化提高了分析方法的灵敏度，并允许对极低水平的 BPA（即 0.78 pmol BPA）进行准确定量。在一年的时间里，BPA 在乙醇中从所有四种测试的复合材料中连续洗脱。当乙醇用作提取溶液时，BPA 洗脱明显更高。在水中，洗脱的 BPA 最多可以检测到一年，但几周后就无法准确量化其水平。

意义

复合材料可被视为 BPA 的潜在长期来源，因此在评估内分泌干扰化学品的总体暴露情况时不应忽视。