Yang Seo-Young, Koh Young-Hag, Kim Hyoun-Ee
Interdisciplinary Program in Precision Public Health, Korea University, Seoul 02841, Republic of Korea.
School of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea.
Materials (Basel). 2023 Jan 1;16(1):402. doi: 10.3390/ma16010402.
This study reports the utility of solid camphor as a novel diluent in photocurable hexanediol diacrylate (HDDA) monomer to manufacture 4 mol% yttria partially stabilized zirconia (4Y-PSZ) components for dental applications by digital light processing (DLP). The use of a 65 wt% HDDA-35 wt% camphor solution allowed 4Y-PSZ suspensions to have reasonably low viscosities (1399 ± 55.8 mPa·s at a shear rate of 75 s), measured by a cone/plate viscometer, at a high solid loading of 48 vol%, where 4Y-PSZ particles prepared by calcination of as-received 4Y-PSZ granules, followed by a ball-milling process, were used with assistance of a dispersant. These 4Y-PSZ suspensions could be successfully applied to our custom-made DLP machine for manufacturing 4Y-PSZ components. To this end, several processing parameters, including layer thickness of 4Y-PSZ suspension, UV illumination time for layer-by-layer photocuring process, and initial dimensions of 4Y-PSZ objects, were tightly controlled. As sintering temperature increased from 1300 °C to 1500 °C, relative density and grain size of 4Y-PSZ objects increased, and cubic phase content also increased. Thus, after sintering at the highest temperature of 1500 °C for 3 h, high mechanical properties (biaxial flexural strength = 911 ± 40.7 MPa, hardness = 1371 ± 14.4 H) and reasonably high optical transmittance (translucency parameter = 7.77 ± 0.32, contrast ratio = 0.809 ± 0.007), evaluated by a spectrophotometer, were obtained due to a high relative density (97.2 ± 1.38%), which would be useful for dental applications.
本研究报告了固体樟脑作为一种新型稀释剂在光固化己二醇二丙烯酸酯（HDDA）单体中的应用，通过数字光处理（DLP）制造用于牙科应用的4摩尔%氧化钇部分稳定氧化锆（4Y-PSZ）部件。使用65 wt% HDDA - 35 wt%樟脑溶液，在48 vol%的高固体含量下，通过锥板粘度计测量，4Y-PSZ悬浮液具有相当低的粘度（在75 s-1的剪切速率下为1399±55.8 mPa·s），其中通过煅烧接收的4Y-PSZ颗粒，然后进行球磨工艺制备的4Y-PSZ颗粒，在分散剂的辅助下使用。这些4Y-PSZ悬浮液可以成功应用于我们定制的DLP机器以制造4Y-PSZ部件。为此，严格控制了几个加工参数，包括4Y-PSZ悬浮液的层厚、逐层光固化过程的紫外线照射时间以及4Y-PSZ物体的初始尺寸。随着烧结温度从1300℃升高到1500℃，4Y-PSZ物体的相对密度和晶粒尺寸增加，立方相含量也增加。因此，在1500℃的最高温度下烧结3小时后，通过分光光度计评估，由于高相对密度（97.2±1.38%），获得了高机械性能（双轴弯曲强度 = 911±40.7 MPa，硬度 = 1371±14.4 H）和相当高的光学透过率（半透明度参数 = 7.77±0.32，对比度 = 0.809±0.007），这对于牙科应用将是有用的。
