Bassenheim David, Rist Kai, Moszner Norbert, Catel Yohann, Liska Robert, Knaack Patrick
Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163 MC, A-1060 Vienna, Austria.
Ivoclar Vivadent AG, Bendererstrasse 2, FL-9494 Schaan, Liechtenstein.
Polymers (Basel). 2024 Aug 16;16(16):2323. doi: 10.3390/polym16162323.
Color stability is crucial for dental materials to ensure they perfectly match a patient's tooth color. This is particularly challenging in photoresist-based additive manufacturing. Although some studies have addressed this issue, the exact causes of discoloration and ways to minimize it remain unclear. In this study, the intrinsic causes of discoloration in materials intended for 3D printing are investigated by examining thin-film samples (1200 µm) of various compositions, which are stored under different conditions. The samples are evaluated by measuring the UV-Vis absorption spectra at regular intervals to monitor changes. The findings reveal that both the composition of the formulations and the storage conditions significantly influence the discoloration behavior. Furthermore, methods have been developed to reduce or completely prevent discoloration. The use of photoinitiators with sterically demanding benzoyl moieties, as well as the addition of stabilizers, effectively decreases the intensity of emerging discoloration. Furthermore, incorporating the oxidizing agent cumene hydroperoxide (CHP) results in materials that maintain color stability.
颜色稳定性对于牙科材料至关重要，以确保它们与患者牙齿颜色完美匹配。这在基于光刻胶的增材制造中尤其具有挑战性。尽管一些研究已经探讨了这个问题，但变色的确切原因以及将其最小化的方法仍不清楚。在本研究中，通过检查不同成分的薄膜样品（1200 µm）来研究用于3D打印的材料变色的内在原因，这些样品在不同条件下储存。通过定期测量紫外-可见吸收光谱来评估样品，以监测变化。研究结果表明，配方组成和储存条件都对变色行为有显著影响。此外，已经开发出减少或完全防止变色的方法。使用具有空间位阻较大的苯甲酰基部分的光引发剂，以及添加稳定剂，可有效降低出现的变色强度。此外，加入氧化剂异丙苯过氧化氢（CHP）可使材料保持颜色稳定性。
