Takahashi T
Department of Dental Materials, Nihon University School of Dentistry.
Shika Zairyo Kikai. 1990 May;9(3):412-9.
The quantity of the remaining double bonds (RDB) in polymerized visible light cured resins has been determined. Five trial unfilled resins, eight commercial composite resins and three commercial crown and bridge resins were investigated by Fourier transform infrared spectrophotometer with the liquid-film method. Infrared absorbance was measured before irradiation and at various times after irradiation. The quantity of RDB was determined and the data expressed as percentage of the total amount of double bonds in the unpolymerized resins. The quantity of RDB of five trial unfilled resins decreased linearly corresponding to the logarithmic time after the start of irradiation. The difference in the quantity of RDB at 5 min and decreasing rate of RDB could be seen in accordance with the kind of monomer. Among five trial unfilled resins, one with BMPEPP (BPE-200) used as monomer gave the smallest RDB, and one with 4 PN-(TF)2-(EMA)6 used as monomer gave the largest value. The quantity of RDB in the unfilled resin with Tri-EDMA at 5 min decreased in accordance with the irradiation time, but after 1 month, it showed almost the same value irrespective of the irradiation time. The quantity of RDB of commercial composite resins and crown and bridge resins decreased linearly corresponding to logarithmic time. In all commercial resins, the quantity of RDB became small when the base monomer was Bis-GMA but large when it was UDMA.
已测定了聚合可见光固化树脂中剩余双键（RDB）的含量。采用液膜法，通过傅里叶变换红外分光光度计对5种试验用无填料树脂、8种市售复合树脂和3种市售冠桥树脂进行了研究。在辐照前和辐照后的不同时间测量红外吸光度。测定RDB的含量，并将数据表示为未聚合树脂中双键总量的百分比。5种试验用无填料树脂的RDB含量随辐照开始后的对数时间呈线性下降。根据单体种类的不同，可以看出5分钟时RDB含量的差异以及RDB的下降速率。在5种试验用无填料树脂中，以BMPEPP（BPE - 200）作为单体的树脂RDB含量最小，以4 PN-(TF)2-(EMA)6作为单体的树脂RDB含量最大。含三乙二甲基丙烯酸酯的无填料树脂在5分钟时的RDB含量随辐照时间下降，但1个月后，无论辐照时间如何，其RDB含量几乎相同。市售复合树脂和冠桥树脂的RDB含量随对数时间呈线性下降。在所有市售树脂中，当基础单体为双酚A - 二甲基丙烯酸缩水甘油酯（Bis - GMA）时，RDB含量较低；当基础单体为聚氨酯二甲基丙烯酸酯（UDMA）时，RDB含量较高。
