Analysis of estrogenic activity of resin composites in vitro and in vivo

含有各种单体和添加剂的商用复合材料的雌激素原性尚未完全阐明。本研究采用报告基因法检测了24种复合材料的体外雌激素活性。从复合材料中鉴定出的18种化学物质的雌激素性也通过报告基因测定进行了评估。此外，在体外证实具有雌激素活性的化学物质的雌激素活性在体内进行了检查（子宫营养试验）。在24种复合材料中，有6种产品具有体外雌激素，但没有一种样品含有双酚a。在18种化学物质中，1种光稳定剂（2-羟基-4-甲氧基-二苯甲酮，HMBP）、1种光引发剂（2,2-二甲氧基-2-苯基-苯乙酮，DMPA）和1种抑制剂（2,6-二叔丁基-羟基-甲酚，BHT）在体外表现出显著的雌激素活性。4种雌激素洗脱液中HMBP浓度均大于具有雌激素性的最低浓度。其他2种雌激素浓度。此外，在任何洗脱液中均未发现BHT。因此，体外观察到的复合材料的雌激素活性与HMBP或DMPA的洗脱有关。相反，HMBP和DMPA在体内均未表现出雌激素性。这些结果表明，从树脂复合材料中洗脱的化学物质模拟天然类固醇激素的可能性可以忽略不计。

Estrogenicity of commercial composites, which contain various monomers and additives, has not yet been fully elucidated. In this study, the estrogenic activities of eluates obtained from 24 composites were examined in vitro (reporter gene assay). The estrogenicity of 18 chemicals identified from the composites was also assessed by a reporter gene assay. Furthermore, the estrogenic activity of the chemicals, which were confirmed to have estrogenic activity in vitro, was examined in vivo (uterotrophic assay).Among 24 composites, six products were estrogenic in vitro, although none of the specimens contained bisphenol-A. Moreover, one photostabilizer (2-hydroxy-4-methoxy-benzophenone, HMBP), one photoinitiator (2,2-dimethoxy-2-phenyl-acetophenone, DMPA), and one inhibitor (2,6-di-tert-butyl-ρ-cresol, BHT) showed significant estrogenic activities among 18 chemicals in vitro. The concentrations of HMBP in 4 estrogenic eluates were greater than the minimum concentration to show estrogenicity. For other 2 estrogenic concentration. In addition, BHT was not identified in any of the eluates. Therefore, the estrogenic activites of composites observed in vitro were associated with the elution of HMBP or DMPA. On the contrary, neither HMBP nor DMPA showed estrogenicity in vivo. These results suggest that the possibilities of the chemicals eluted from resin composites mimicking natural steroid hormones are negligible.