Oral Rehabilitation & Dental Biomaterial and Bioengineering, Sydney Dental School, Faculty of Medicine and Health, The University of Sydney, Australia.
Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Biomed Res Int. 2022 Feb 21;2022:8353137. doi: 10.1155/2022/8353137. eCollection 2022.
Recently, dentists can utilize three-dimensional printing technology in fabricating dental restoration. However, to date, there is a lack of evidence regarding the effect of printing layer thicknesses and postprinting on the mechanical properties of the 3D-printed temporary restorations with the additive manufacturing technique. So, this study evaluated the mechanical properties of a 3D-printed dental resin material with different printing layer thicknesses and postprinting methods.
210 specimens of a temporary crown material (A2 EVERES TEMPORARY, SISMA, Italy) were 3D-printed with different printing layer thicknesses (25, 50, and 100 m). Then, specimens were 3D-printed using DLP technology (EVERES ZERO, DLP 3D printer, SISMA, Italy) which received seven different treatment conditions after printing: water storage for 24 h or 1 month, light curing or heat curing for 5 or 15 minutes, and control. Flexural properties were evaluated using a three-point bending test on a universal testing machine (ISO standard 4049). The Vickers hardness test was used to evaluate the microhardness of the material system. The degree of conversion was measured using an FT-IR ATR spectrophotometer. Statistical analysis was performed using two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test ( ≤ 0.05).
The 100 m printing layer thickness had the highest flexural strength among the other thickness groups. As a combined effect printing thickness and postprinting conditions, the 100 m with the dry storage group has the highest flexural strength among the tested groups (94.60 MPa). Thus, the group with 100 m thickness that was heat cured for 5 minutes (HC 5 min 100 m) has the highest VHN value (VHN = 17.95). Also, the highest mean DC% was reported by 50 m layer thickness (42.84%).
The thickness of the 100 m printing layer had the highest flexural strength compared to the 25 m and 50 m groups. Also, the postprinting treatment conditions influenced the flexural strength and hardness of the 3D-printed resin material.
最近，牙医可以在制作牙科修复体中使用三维打印技术。然而，迄今为止，关于在添加剂制造技术中使用不同的打印层厚度和后打印对 3D 打印临时修复体的机械性能的影响，还缺乏证据。因此，本研究评估了不同打印层厚度和后打印方法的 3D 打印牙科树脂材料的机械性能。
使用不同的打印层厚度（25、50 和 100 μm）对 210 个临时冠材料（A2 EVERES TEMPORARY，SISMA，意大利）样本进行 3D 打印。然后，使用 DLP 技术（EVERES ZERO，DLP 3D 打印机，SISMA，意大利）对样本进行 3D 打印，打印后对样本进行七种不同的处理：水储存 24 小时或 1 个月、光固化或热固化 5 或 15 分钟，以及对照组。使用万能试验机（ISO 标准 4049）对弯曲性能进行评估。使用维氏硬度试验评估材料系统的显微硬度。使用傅里叶变换红外衰减全反射光谱仪测量转化率。使用双向方差分析（ANOVA）和 Tukey 的诚实显著差异（HSD）检验（≤0.05）进行统计分析。
100 μm 打印层厚度在其他厚度组中具有最高的弯曲强度。作为打印厚度和后打印条件的综合影响，在测试组中，干燥储存组的 100 μm 厚度具有最高的弯曲强度（94.60 MPa）。因此，5 分钟热固化组（HC 5 min 100 μm）的维氏硬度值最高（VHN = 17.95）。此外，50 μm 层厚度报告的平均 DC%最高（42.84%）。
与 25 μm 和 50 μm 组相比，100 μm 打印层的厚度具有最高的弯曲强度。此外，后打印处理条件影响 3D 打印树脂材料的弯曲强度和硬度。
