Beriat Nilufer C, Ertan Atilla, Cehreli Zafer C, Gulsahi Kamran
School of Dental Technology, Hacettepe University, Ankara, Turkey.
J Endod. 2009 Jan;35(1):110-2. doi: 10.1016/j.joen.2008.09.018. Epub 2008 Nov 7.
The purpose of this study was to investigate the degree of conversion of a methacrylate-based sealer (Epiphany; Pentron Clinical Technologies, Wallingford, CT) with regard to the method of photoactivation, distance from the light-curing unit (LCU), and post-curing time. Freshly mixed Epiphany sealer was dispensed into half-pipe-shaped silicone moulds (n = 48), after which the specimens were photoactivated with one of the following LCUs from the coronal aspect: (1) quartz tungsten halogen/40 seconds and (2) light-emitting diode/20 seconds. In each specimen, the degree of conversion was measured at three different locations (coronal, middle, and apical) using Fourier transform infrared spectroscopy before and after photoactivation. The amount of conversion was approximately 50% after photoactivation and improved by approximately 10% after 15 days. Conversion of Epiphany was not affected by the type of LCU (p > 0.001) or the distance from the LCU (p > 0.001) but showed a significant increase within time (p < 0.001). These results indicate incomplete polymerization of Epiphany, despite a post-curing time of as long as 2 weeks in vitro.
本研究的目的是研究一种甲基丙烯酸酯类封闭剂（Epiphany；Pentron Clinical Technologies，沃灵福德，康涅狄格州）在光活化方法、距光固化装置（LCU）的距离和后固化时间方面的转化程度。将新鲜混合的Epiphany封闭剂注入半管状硅树脂模具（n = 48）中，然后从冠方用以下LCU之一对标本进行光活化：（1）石英钨卤素灯/40秒和（2）发光二极管/20秒。在每个标本中，在光活化前后使用傅里叶变换红外光谱法在三个不同位置（冠方、中间和根尖）测量转化程度。光活化后转化率约为50%，15天后提高约10%。Epiphany的转化率不受LCU类型（p > 0.001）或距LCU距离（p > 0.001）的影响，但随时间显著增加（p < 0.001）。这些结果表明，尽管在体外后固化时间长达2周，Epiphany仍存在不完全聚合的情况。
