Lee S Y, Huang H M, Lin C Y, Shih Y H
School of Dentistry, Taipei Medical College, Wan-Fang Hospital, Taiwan, ROC.
J Oral Rehabil. 1998 Aug;25(8):575-88. doi: 10.1046/j.1365-2842.1998.00284.x.
The aim of this study was to analyse the leached moieties of dental composites after storage in ethanol and organic acids of plaque and further evaluate the resultant effect on the diametral tensile strength (DTS) of the composites. Three commercial composites were used: Bis-GMA-based Z100, Bis-GMA/UDMA-based Heliomolar, and Bis-MPEPP-based Marathon One. The solutions used were: 99.9% acetic acid, 99% propionic acid and 75% ethanol. Specimens (4 mm diam. x 2 mm thick) were stored at 37 degrees C in 3 mL of solution for up to 30 days. Gas chromatography/mass spectrometry was used to characterize the leached moieties and DTS of the specimens after immersion was evaluated. Data were analysed using ANOVA and Tukey LSD test. The eluted substances were not all the same in different solutions and composites but mostly increased with immersion time, and included diluents (TEGDMA and decamethacrylate) and some additives, such as an ultra-violet stabilizer (TINUVINP), plasticizers (dicyclohexyl phthalate and bis(2-ethylhexyl) phthalate), initiator (triphenyl stibine), coupling agent (gamma-methacryloxypropyl trimethoxysilane), and phenyl benzoate. The chief polymerizing monomers were not found. More kinds of components were found in the acetic acid and ethanol groups studied. The fewest kinds and quantities of leached moieties were found for Bis-GMA specimens and then Bis-GMA/UDMA ones, most of which are diluent agents. Bis-MPEPP specimens leached the most substances, which were composed mostly of a short phenyl group chain structure. The BisGMA composite showed the highest DTS (54.8 +/- 5.7 MPa), which was not greatly affected by the length of storage. Bis-GMA/UDMA (36.2 +/- 6.8 MPa) and Bis-MPEPP (26.1 +/- 4.5 MPa) composites were significantly reduced (P < 0.05) after 30 days storage in the ethanol (35-50%), in the propionic acid (25-30%), and in the acetic acid (40-60%). Irreversible processes such as the leaching of components occur in fluids simulating an oral environment, which may contribute to irreversible material degradation, especially for non-Bis-GMA-based composites.
本研究的目的是分析牙科复合材料在乙醇和菌斑中的有机酸中储存后的浸出成分，并进一步评估其对复合材料径向拉伸强度（DTS）的影响。使用了三种市售复合材料：基于双酚A缩水甘油醚（Bis-GMA）的Z100、基于双酚A缩水甘油醚/二甲基丙烯酸聚氨酯（Bis-GMA/UDMA）的Heliomolar和基于双甲基丙烯酸聚乙烯基酯丙酯（Bis-MPEPP）的Marathon One。所使用的溶液为：99.9%的乙酸、99%的丙酸和75%的乙醇。将试样（直径4 mm×厚2 mm）在37℃下于3 mL溶液中储存长达30天。使用气相色谱/质谱法对浸出成分进行表征，并评估浸泡后试样的DTS。数据采用方差分析和Tukey LSD检验进行分析。不同溶液和复合材料中的洗脱物质并不完全相同，但大多随浸泡时间增加，包括稀释剂（三乙二醇二甲基丙烯酸酯和十甲基丙烯酸酯）和一些添加剂，如紫外线稳定剂（TINUVINP）、增塑剂（邻苯二甲酸二环己酯和邻苯二甲酸二（2-乙基己基）酯）、引发剂（三苯基锑）、偶联剂（γ-甲基丙烯酰氧基丙基三甲氧基硅烷）和苯甲酸苯酯。未发现主要的聚合单体。在研究的乙酸和乙醇组中发现了更多种类的成分。Bis-GMA试样浸出的成分种类和数量最少，其次是Bis-GMA/UDMA试样，其中大部分是稀释剂。Bis-MPEPP试样浸出的物质最多，主要由短苯基链结构组成。BisGMA复合材料显示出最高的DTS（54.8±5.7 MPa），其受储存时间的影响不大。在乙醇（35 - 50%）、丙酸（25 - 30%）和乙酸（40 - 60%）中储存30天后，Bis-GMA/UDMA（36.2±6.8 MPa）和Bis-MPEPP（26.1±4.5 MPa）复合材料的DTS显著降低（P < 0.05）。在模拟口腔环境的流体中会发生如成分浸出等不可逆过程，这可能导致材料的不可逆降解，尤其是对于非Bis-GMA基复合材料。
