Catel Yohann, Angermann Jörg, Grob Benjamin, Fässler Pascal, Lamparth Iris, Schnur Thomas
Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
Dent Mater. 2023 Oct;39(10):886-893. doi: 10.1016/j.dental.2023.07.007. Epub 2023 Aug 15.
Currently used thiourea-based two-component dental materials may release bitter compounds if they are not properly cured. To address this issue, the objective of this study was to evaluate the potential of acylthiourea oligomers as reducing agents for the development of self-cure composites.
Acylthiourea oligomers ATUO1-3 were synthesized via cotelomerization of the acylthiourea methacrylate ATU1 with butyl methacrylate. They were characterized by H NMR spectroscopy and size exclusion chromatography. Self-cure composites based on the redox initiator system cumene hydroperoxide/acylthiourea oligomer/copper(II) acetylacetonate were formulated. The flexural strength and modulus were measured using a three-point bending setup. The double bond conversions were determined using NIR spectroscopy. The working time of each self-cure composite was measured using an oscillating rheometer. Leaching experiments using light-cure composites were performed in DMSO-d6.
Acylthiourea oligomers ATUO1-3 were successfully synthesized in good yields. Both the oligomer molecular weight and the amount of thiourea groups were varied. Self-cure composites containing ATUO1 or ATUO2 as reducing agents exhibited excellent mechanical properties and high double-bond conversions. The amounts of reducing agent, cumene hydroperoxide and copper(II) acetylacetonate were shown to have a significant impact on the working time. Moreover, a correlation between flexural modulus and the amount of metal salt was clearly established. Self-cure composites containing the oligomer ATUO1 exhibited a longer working time than materials containing ATU1 or acetylthiourea. Contrary to acetylthiourea, ATUO1 was not able to leach out of light-cured composites.
Acylthiourea oligomers are promising reducing agents for the formulation of two-component dental materials that do not induce a bitter taste in mouth.
目前使用的硫脲基双组分牙科材料如果固化不当可能会释放出苦味化合物。为解决这一问题，本研究的目的是评估酰基硫脲低聚物作为还原剂用于开发自固化复合材料的潜力。
通过甲基丙烯酸酰基硫脲（ATU1）与甲基丙烯酸丁酯的共调聚反应合成了酰基硫脲低聚物ATUO1 - 3。通过核磁共振氢谱和尺寸排阻色谱对其进行了表征。基于氧化还原引发体系异丙苯过氧化氢/酰基硫脲低聚物/乙酰丙酮铜（II）配制了自固化复合材料。使用三点弯曲装置测量弯曲强度和模量。使用近红外光谱法测定双键转化率。使用振荡流变仪测量每种自固化复合材料的工作时间。在氘代二甲基亚砜中对光固化复合材料进行浸出实验。
成功合成了产率良好的酰基硫脲低聚物ATUO1 - 3。低聚物分子量和硫脲基团数量均有所变化。含有ATUO1或ATUO2作为还原剂的自固化复合材料表现出优异的机械性能和高双键转化率。结果表明，还原剂、异丙苯过氧化氢和乙酰丙酮铜（II）的用量对工作时间有显著影响。此外，还明确建立了弯曲模量与金属盐用量之间的相关性。含有低聚物ATUO1的自固化复合材料比含有ATU1或乙酰硫脲的材料具有更长的工作时间。与乙酰硫脲不同，ATUO1不会从光固化复合材料中浸出。
酰基硫脲低聚物是用于配制不会在口腔中引起苦味的双组分牙科材料的有前途的还原剂。
