Durner Jürgen, Obermaier Julia, Ilie Nicoleta
Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology und Toxicology, Nussbaumstr. 26, 80336 Munich, Germany.
Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr. 70, 80336 Munich, Germany.
Dent Mater. 2014 Feb;30(2):192-9. doi: 10.1016/j.dental.2013.11.003. Epub 2013 Dec 11.
To analyse the influence of irradiation time, aging before bleaching, and bleaching technique (home bleaching vs. in-office bleaching) on the amount of elutable substances from modern nano-hybrid resin-based composites (RBCs).
Specimens (n=5) of three nano-hybrid RBCs (Venus(®) Diamond, Tetric EvoCeram(®) and Filtek™ Supreme XTE) were irradiated for 5, 10, 20 and 40s. The degree of conversion (DC) was measured in real-time with Fourier transform infrared spectroscopy (FTIR). Specimens were bleached either directly after irradiation or after aging (1.5 or 6 month in distilled water at 37°C) with Opalescence(®) PF15% for 6h (simulation of home bleaching) or PF35% for 0.5h (simulation of in-office bleaching) and incubated in ethanol/water (3:1) at 37°C for 7d. The eluates were analyzed by gas chromatography/mass spectrometry. Unbleached specimens at the above mentioned irradiation times were used as controls.
Bleaching increases the amount of elutable substances. This amount is generally stronger influenced by aging than by polymerization time or concentration of the gel. 2-Hydroxyethyl methacrylate was found in amounts up to 334.14 (106.91) μmol/l (Tetric EvoCeram(®), irradiation time 5s; bleaching with 15% CP) as a destruction product. Diethoyxdimethylsilane was found in all eluates from bleached specimens, but not in the control groups. This substance may be formed by oxidation of 3-methacryloxy-propyltrimethoxysilane, indicating that the bond between inorganic filler and organic matrix might be weakened after bleaching.
Bleaching gels might alter the physical properties of resin-based composites, especially at low irradiation times and fresh placed restorations.
分析照射时间、漂白前老化以及漂白技术（家庭漂白与诊室漂白）对现代纳米混合树脂基复合材料（RBCs）中可洗脱物质含量的影响。
对三种纳米混合RBCs（Venus(®) Diamond、Tetric EvoCeram(®)和Filtek™ Supreme XTE）的样本（n = 5）分别照射5、10、20和40秒。采用傅里叶变换红外光谱（FTIR）实时测量转化率（DC）。样本在照射后或老化后（37℃蒸馏水中1.5或6个月），用Opalescence(®) PF15%漂白6小时（模拟家庭漂白）或PF35%漂白0.5小时（模拟诊室漂白），然后在37℃的乙醇/水（3:1）中孵育7天。通过气相色谱/质谱分析洗脱液。将上述照射时间下未漂白的样本用作对照。
漂白会增加可洗脱物质的含量。该含量一般受老化的影响比聚合时间或凝胶浓度的影响更大。作为降解产物，在高达334.14（106.91）μmol/l的含量中发现了甲基丙烯酸2 - 羟乙酯（Tetric EvoCeram(®)，照射时间5秒；15% CP漂白）。在所有漂白样本的洗脱液中都发现了二乙氧基二甲基硅烷，但对照组中未发现。这种物质可能是由3 - 甲基丙烯酰氧基丙基三甲氧基硅烷氧化形成的，表明漂白后无机填料与有机基质之间的键可能会被削弱。
漂白凝胶可能会改变树脂基复合材料的物理性能，尤其是在低照射时间和新放置的修复体中。
