Department of Restorative Odontology and Endodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia.
J Biomed Mater Res B Appl Biomater. 2013 Jan;101(1):61-7. doi: 10.1002/jbm.b.32815. Epub 2012 Sep 21.
Elution of potentially toxic substances, including monomers, from resin-based dental composites may affect the biocompatibility of these materials in clinical conditions. In addition to the amounts of eluted monomers, mathematical modeling of elution kinetics reveals composite restorations as potential chronic sources of leachable monomers. The aim of this work was to experimentally quantify elution of main cross-linking monomers from four commercial composites and offer a mathematical model of elution kinetics. Composite samples (n = 7 per group) of Filtek Supreme XT (3M ESPE), Tetric EvoCeram (Ivoclar Vivadent), Admira (Voco), and Filtek Z250 (3M ESPE) were prepared in 2-mm thick Teflon moulds and cured with halogen or light-emitting diode light. Monomer elution in ethanol and water was analyzed using high-performance liquid chromatography up to 28 days postimmersion. The mathematical model was expressed as a sum of two exponential regression functions representing the first-order kinetics law. Elution kinetics in all cases followed the same mathematical model though differences in rate constants as well as the extent of monomer elution were material-, LCU-, medium-dependent. The proposed mechanisms of elution indicate fast elution from surface and subsurface layers and up to 100 times slower monomer extraction from the bulk polymer.
从树脂基牙科复合材料中洗脱潜在有毒物质，包括单体，可能会影响这些材料在临床条件下的生物相容性。除了洗脱单体的量之外，洗脱动力学的数学模型还揭示了复合材料修复体是可浸出单体的潜在慢性来源。本工作的目的是从四种商业复合材料中实验定量洗脱主要交联单体，并提供洗脱动力学的数学模型。将 Filtek Supreme XT（3M ESPE）、Tetric EvoCeram（Ivoclar Vivadent）、Admira（Voco）和 Filtek Z250（3M ESPE）的复合材料样品（每组 7 个）在 2 毫米厚的聚四氟乙烯模具中制备，并通过卤素或发光二极管光固化。在浸渍后 28 天内，使用高效液相色谱法分析乙醇和水中的单体洗脱情况。该数学模型表示为两个指数回归函数的和，代表一级动力学定律。尽管速率常数以及单体洗脱的程度取决于材料、LCU 和介质，但所有情况下的洗脱动力学都遵循相同的数学模型。洗脱机制表明从表面和次表面层快速洗脱，而从聚合物本体中以快 100 倍的速度提取单体。
