Buck R A, Cai J, Eleazer P D, Staat R H, Hurst H E
University of Louisville, KY, USA.
J Endod. 2001 May;27(5):325-7. doi: 10.1097/00004770-200105000-00003.
The effects of endodontic irrigants and calcium hydroxide on lipopolysaccharide (LPS; endotoxin) were analyzed using the highly selective technique of mass spectrometry/gas chromatography with selected ion monitoring. An aqueous solution of LPS was mixed with one of a variety of endodontic irrigants for 30 min. Because it is a commonly used interappointment dressing, calcium hydroxide was also applied to LPS for 1, 2, or 5 days. LPS inactivation was measured by quantitation of free fatty acid release. Water, EDTA, ethanol, 0.12% chlorhexidine, chlorhexidine + sodium hypochlorite, and sodium hypochlorite alone showed little breakdown of LPS. Long-term calcium hydroxide--as well as 30-min exposure to an alkaline mixture of chlorhexidine, ethanol, and sodium hypochlorite--did detoxify LPS molecules by hydrolysis of ester bonds in the fatty acid chains of the lipid A moiety.
采用具有选择离子监测功能的质谱/气相色谱这种高选择性技术，分析了根管冲洗剂和氢氧化钙对脂多糖（LPS；内毒素）的影响。将LPS水溶液与多种根管冲洗剂之一混合30分钟。由于氢氧化钙是常用的诊间封药，因此也将其应用于LPS 1、2或5天。通过定量游离脂肪酸释放来测定LPS的失活情况。水、乙二胺四乙酸（EDTA）、乙醇、0.12%氯己定、氯己定+次氯酸钠以及单独的次氯酸钠对LPS的分解作用很小。长期使用氢氧化钙以及将LPS暴露于氯己定、乙醇和次氯酸钠的碱性混合物中30分钟，确实会通过水解脂多糖A部分脂肪酸链中的酯键使LPS分子解毒。
