PRECISE ANALYSIS AND DISSOLVING BEHAVIOR OF BISPHENOL A (ENDOCRINE DISRUPTING CHEMICAL) IN DENTAL MATERIALS.

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The pit and fissure sealant is used very frequently in the pediatric dentistry clinic. It is possible that bisphenol A, one of the endocrine disturbing chemicals, might be contained in the sealant. The concentration of the bisphenol A in the sealant was measured in this study.In the first year, analysis of estrogen and bisphenol A was conducted using a yeast-based steroid hormone receptor gene transcription assay. A linear dose response relation was obtained between 10ィイD1-8ィエD1M to 10ィイD1-7ィエD1M for estrogen and 10ィイD1-4ィエD1M to 10ィイD1-3ィエD1M for bisphenol A. Higher or lower concentration that these ranges resulted in a lower estrogenic reaction. These data indicated that bisphenol A had 10ィイD1-4ィエD1 of reactivity than estrogen. Because of the poisonous nature of the sealant itself, about 20 times of dilution was necessary to apply sealant to the assay. This concentration did not cause any estrogenic reaction. In the second year, GCMS method was used in order to analyze much smaller amount of bisphenol A. As only very small amount of bisphenol A exists in sealant, a concentration and purification procedure was conducted before the application of the sample. Two times of extraction of bisphenol A were conducted with 30 ml of methanol against 2.5185 g of sealant. The extract was applied to silicagel chromatography containing 5 % water for the purification. This purified sample was applied to the GCMS and finally 0.025μg of bisphenol A was detected per 1 g of sealant.