Department of Orthodontics, Institute of Craniofacial Deformity, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea.
BK21 FOUR Project, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea.
Dent Mater. 2024 Oct;40(10):1575-1583. doi: 10.1016/j.dental.2024.07.009. Epub 2024 Jul 26.
This study aimed to use a carboxybetaine methacrylate (CBMA) copolymer solution to surface treat 3D printed clear aligners at different fabrication stages, to impart antifouling properties, and assess the surface treatment at various fabrication stages' impact on physico-mechanical characteristics.
Surface treatments using a blend of 2-hydroxyethyl methacrylate (HEMA) and CBMA, termed CCS, were performed at various stages of 3D printed clear aligner fabrication. Experimental groups, CB1, CB2, and CB3, were determined by the stage of surface treatment during post-processing. CB1, CB2, and CB3 received treatment before post-curing, after post-curing, and after post-processing, respectively. Untreated samples served as controls. Physical and mechanical properties were assessed through tensile testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and UV-Vis spectroscopy. The surface was further characterized through scanning electron microscopy and contact angle measurements. The cytotoxicity was assessed with 7-day elution and agar diffusion assays. Lastly, bacterial biofilm resistance was evaluated using confocal laser scanning microscopy. Crystal violet assay was performed using Streptococcus mutans.
Surface treatment during CB1 stage exerted the most significantly unfavorable influence on properties of the 3D printed aligner resin. CB2 samples showed the maximum preservation of translucency even after 7-day aging. CB2 and CB3 phases showed enhanced hydrophilicity of sample surfaces with reduced adhesion of multispecies biofilm and S. mutans.
Application of CCS surface treatment immediately after post-curing (CB2) can enhance the biofilm resistance of 3D printed clear aligners while maintaining high fidelity to optical translucency and constituent mechanical properties.
本研究旨在使用羧基甜菜碱甲基丙烯酸酯（CBMA）共聚物溶液对 3D 打印透明矫正器在不同制造阶段进行表面处理，赋予其抗污性能，并评估不同制造阶段的表面处理对物理机械性能的影响。
使用 2-羟乙基甲基丙烯酸酯（HEMA）和 CBMA 的混合物（称为 CCS）对 3D 打印透明矫正器制造的各个阶段进行表面处理。实验分组为 CB1、CB2 和 CB3，根据后处理过程中的表面处理阶段确定。CB1、CB2 和 CB3 分别在后固化前、后固化后和后处理后进行处理。未处理的样本作为对照。通过拉伸试验、傅里叶变换红外光谱（FTIR）、差示扫描量热法（DSC）和紫外可见光谱评估物理和机械性能。通过扫描电子显微镜和接触角测量进一步表征表面。通过共聚焦激光扫描显微镜评估细胞毒性。使用 7 天洗脱和琼脂扩散试验评估细菌生物膜的抵抗力。使用 Streptococcus mutans 进行结晶紫试验评估抗细菌生物膜能力。
CB1 阶段的表面处理对 3D 打印矫正器树脂的性能产生了最显著的不利影响。即使经过 7 天老化，CB2 样本的透光率保持最大。CB2 和 CB3 阶段显示出样品表面亲水性增强，多种生物膜和 S. mutans 的黏附减少。
立即在后固化后（CB2）进行 CCS 表面处理可以增强 3D 打印透明矫正器的抗生物膜能力，同时保持光学透明度和组成机械性能的高保真度。
