Bayarsaikhan Enkhjargal, Lim Jung-Hwa, Shin Seung-Ho, Park Kyu-Hyung, Park Young-Bum, Lee Jae-Hoon, Kim Jong-Eun
Department of Prosthodontics, Yonsei University College of Dentistry, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Korea.
Oral Research Science Center, BK21 FOUR Project, Department of Prosthodontics, College of Dentistry, Yonsei University, Yonsei-ro 50-1, Seodaemun-gu, Seoul 03722, Korea.
Polymers (Basel). 2021 Apr 7;13(8):1180. doi: 10.3390/polym13081180.
Three-dimensional (3D) printing is an attractive technology in dentistry. Acrylic-based 3D printed resin parts have to undergo postcuring processes to enhance their mechanical and biological properties, such as UV-light and thermal polymerization. However, no previous studies have revealed how the postcuring temperature influences the biocompatibility of the produced parts. Therefore, we postprocessed 3D printed denture teeth resin under different postcuring temperatures (40, 60 and 80 °C) for different periods (15, 30, 60, 90 and 120 min), and evaluated their flexural properties, Vickers hardness, cell cytotoxicity, cell viability, and protein adsorption. In addition, confocal laser scanning was used to assess the condition of human gingival fibroblasts. It was found that increasing the postcuring temperature significantly improved the flexural strength and cell viability. The flexural strength and cell viability were 147.48 ± 5.82 MPa (mean ± standard deviation) and 89.51 ± 7.09%, respectively, in the group cured at 80 °C for 120 min, which were higher than the values in the 40 and 60 °C groups. The cell cytotoxicity increased in the 40 °C groups and for longer cultivation time. Confocal laser scanning revealed identifiable differences in the morphology of fibroblasts. This study has confirmed that the postcuring temperature influences the final mechanical and biological properties of 3D printed resin.
三维（3D）打印是牙科领域一项颇具吸引力的技术。基于丙烯酸的3D打印树脂部件必须经过后固化处理，以提高其机械性能和生物学性能，如紫外线光固化和热聚合。然而，此前尚无研究揭示后固化温度如何影响所生产部件的生物相容性。因此，我们在不同后固化温度（40、60和80°C）下对3D打印义齿树脂进行了不同时长（15、30、60、90和120分钟）的后处理，并评估了它们的弯曲性能、维氏硬度、细胞毒性、细胞活力和蛋白质吸附情况。此外，还使用共聚焦激光扫描来评估人牙龈成纤维细胞的状况。结果发现，提高后固化温度可显著提高弯曲强度和细胞活力。在80°C下固化120分钟的组中，弯曲强度和细胞活力分别为147.48±5.82MPa（平均值±标准差）和89.51±7.09%，高于40°C和60°C组的值。40°C组的细胞毒性随着培养时间延长而增加。共聚焦激光扫描显示成纤维细胞形态存在明显差异。本研究证实后固化温度会影响3D打印树脂的最终机械性能和生物学性能。
