Stability of silorane dental monomers in aqueous systems
Stability of silorane dental monomers in aqueous systems
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DOI：
10.1016/j.jdent.2005.09.004
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发表时间：
2006-07-01
影响因子：
4.4
通讯作者：
Kostoryz, Elisabet L.
中科院分区：
文献类型：
--
作者：
Eick, J. David;Smith, Robert E.;Kostoryz, Elisabet L.
研究了硅烷（具有环氧乙烷官能团的硅基单体）作为新型低收缩/应力牙科复合材料的基质树脂。已知含有环氧乙烷基团的化合物与水反应，这可能赋予composite.Objective不稳定性：通过测量环氧乙烷基团在水环境中的化学结构的变化来测试硅烷的稳定性。方法：评价两种硅烷（PH-SIL和TET-SIL）及其1：1混合物（SIL-MIX）（n=2-3）。将硅烷在含有和不含1%四氢呋喃（THF）的水溶液中混合，所述四氢呋喃（THF）含有pH 7.4的肝酯酶或环氧化物氢化酶，或pH 1.4的稀HCl。常规的二环氧乙烷3，4-环氧环己基甲基-3，4-环氧环己烷羧酸酯（ECHM-ECHC）和双酚A二缩水甘油醚（BADGE）的稳定性也在类似条件下监测。NMR被用来估计反应的程度，并给出反应产物的结构信息。相反，ECHM-ECHC在pH 1.4下反应形成含有环氧乙烷、酯、羟基和羧酸基团的物质。在肝酯酶存在下，水水解ECHM-ECHC的酯基。在环氧化物氢化酶的存在下，BADGE环氧乙烷基团被水解为二醇，水解范围从0到34%，取决于水环境。结论：在生物流体模拟物中的稳定性和不溶性的siloranes表明，这些可能是更适合于在口腔环境中使用比传统的环氧乙烷功能单体。(C)2005爱思唯尔有限公司保留所有权利。
Siloranes (silicon-based monomers with oxirane functionality) are investigated as matrix resins for new low shrinkage/ stress dental composites. Compounds containing oxirane groups are known to be reactive with water, which could impart instability to the composite.Objective: To test the stability of siloranes by measuring changes in the chemical structure of the oxirane group in aqueous environments.Methods: Two siloranes (PH-SIL and TET-SIL) and their 1:1 mixture (SIL-MIX) were evaluated (n=2-3). Siloranes were mixed in aqueous solutions with and without 1% tetrahydrofuran (THF) containing either liver esterase or epoxide hydrotase at pH 7.4, or dilute HCl at pH 1.4. The stability of conventional dioxiranes 3,4-epoxycyclohexylmethyl-3,4-epoxycyctohexane carboxylate (ECHM-ECHC), and bisphenol A diglycidyl ether (BADGE) were also monitored under similar conditions. NMR was used to estimate the extent of reaction and give structural information about reaction products.Results: Siloranes were found to be stable for 24 h in all aqueous environments tested. In contrast, ECHM-ECHC reacted at pH 1.4 to form species containing oxirane, ester, hydroxyl and carboxylic acid groups. Water hydrolyzed the ester group of ECHM-ECHC in the presence of liver esterase. In the presence of epoxide hydrotase, BADGE oxirane groups were hydrolyzed to diols, hydrolysis ranged from 0 to 34% depending on the aqueous environment.Conclusion: The stability and insolubility of siloranes in biological fluid simulants suggests that these may be more suitable for use in the oral environment than conventional oxirane-functional monomers. (C) 2005 Elsevier Ltd. All rights reserved.