Song Gun, Son Ji-Won, Jang Ji-Hyun, Choi Sung-Hyeon, Jang Woo-Hyung, Lee Bin-Na, Park Chan
Department of Conservative Dentistry, School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
Department of Conservative Dentistry, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Republic of Korea.
J Adv Prosthodont. 2021 Apr;13(2):71-78. doi: 10.4047/jap.2021.13.2.71. Epub 2021 Apr 27.
This study aims to compare the volumetric change, degree of conversion (DOC), and cytotoxicity of 3D-printed restorations post-cured under three different conditions.
3D-printed interim restorations were post-cured under three different conditions and systems: 5 min, 30 min, and 24 h. Three-unit and six-unit fixed dental prostheses (n = 30 for each case) were printed; ten specimens from each group were post-cured and then scanned to compare their volumetric changes. Root-mean-squared (RMS) values of the data were acquired by superimposing the scanned files with original files. Thirty disk-shaped specimens were printed to evaluate the DOC ratio. Fourier transform infrared spectroscopy was used to compare the DOCs of 10 specimens from each group. Human gingival fibroblasts were used to measure the cell viability of every specimen (n = 7). The data from this experiment were employed for one-way analysis of variance and Tukey's post-hoc comparisons.
Differences between the three-unit restorations were statistically insignificant, regardless of the post-curing conditions. However, for the six-unit restorations, a high RMS value was acquired when the post-curing duration was 30 min. The average DOC was approximately 56 - 62%; the difference between each group was statistically insignificant. All the groups exhibited cell viability greater than 70%, rendering them clinically acceptable.
The post-curing conditions influenced the volume when the length of the restoration was increased. However, this deviation was found to be clinically acceptable. Additionally, post-curing did not significantly influence the DOC and cytotoxicity of the restorations.
本研究旨在比较在三种不同条件下后固化的3D打印修复体的体积变化、转化率（DOC）和细胞毒性。
3D打印的临时修复体在三种不同条件和系统下进行后固化：5分钟、30分钟和24小时。打印了三单位和六单位的固定义齿（每种情况n = 30）；每组十个样本进行后固化，然后扫描以比较它们的体积变化。通过将扫描文件与原始文件叠加来获取数据的均方根（RMS）值。打印了30个圆盘形样本以评估DOC比率。使用傅里叶变换红外光谱法比较每组10个样本的DOC。使用人牙龈成纤维细胞测量每个样本的细胞活力（n = 7）。本实验的数据用于单向方差分析和Tukey事后比较。
无论后固化条件如何，三单位修复体之间的差异在统计学上均无显著性。然而，对于六单位修复体，后固化持续时间为30分钟时获得了较高的RMS值。平均DOC约为56 - 62%；每组之间的差异在统计学上无显著性。所有组的细胞活力均大于70%，使其在临床上可以接受。
当修复体长度增加时，后固化条件会影响体积。然而，发现这种偏差在临床上是可以接受的。此外，后固化对修复体的DOC和细胞毒性没有显著影响。
