Department of Prosthetic Dentistry, UKR University Hospital Regensburg, 93042 Regensburg, Germany.
Department of Operative Dentistry and Periodontology, UKR University Hospital Regensburg, 93042 Regensburg, Germany.
J Dent. 2022 May;120:104097. doi: 10.1016/j.jdent.2022.104097. Epub 2022 Mar 22.
Printed splints may be an alternative as a treatment of functional disorders in addition to physical, manual and physiological therapeutics. The objective is to investigate whether different 3D printed splint materials, which are fabricated with different fabrication orientation and post-processing (washing and post polymerisation) exhibit different in vitro cytotoxicity.
600 discs (n = 25 per group, 5mmx1mm) were printed (P30+ DLP-printer, Straumann, CH; 100 µm layer) from splint materials (M1: Luxaprint OrthoPlus, DMG, G; M2: V-Print Splint, Voco, G). Printing was performed under 90° (A1), 45° (A2) or 0° (A3) alignment to the building platform. Specimens were either automatically washed (W1) (Straumann P Wash, Straumann, CH) or manually cleaned (W2) (Voco Pre-/Main-Clean protocol, Voco, G), and post polymerization was performed (P1: Cure, Straumann, CH; P2: Otoflash N171, Ernst Hinrichs Dental, G). RAW264.7 mouse macrophages were exposed to extracts of the specimens and cytotoxicity was determined as cell survival using a crystal violet assay. Optical density values obtained from exposed cell cultures were normalized to untreated controls (100%), summarized as means and statistically analyzed (ANOVA, α=0.05).
Cell survival varied between 9.1+/-1.3% (alignment A2/post cure P2/material M2/wash system W2) and 58.5+/-5.9% (alignment A1/post cure P1/material M1/wash system W1). Univariate analysis of variance revealed significant differences between mean values for post cure (p = 0.000), wash system (p = 0.002) and materials (p = 0.000), but not for the alignment (p = 0.406). With standardised washing and adapted post cure, both tested materials provided lowest cytotoxicity even in all three printing alignments.
The selection of the material as well as the post-processing (post-polymerization, washing procedure) show influence on the in vitro cytotoxicity. Alignment during manufacturing does not affect toxicity.
Materials, washing and post-polymerization should be matched to reduce cytotoxic effects during additive manufacturing.
除物理、手动和生理治疗外，打印夹板可能是治疗功能障碍的另一种选择。目的是研究不同的 3D 打印夹板材料（用不同的制造方向和后处理（清洗和后聚合）制造）是否表现出不同的体外细胞毒性。
从夹板材料（M1：Luxaprint OrthoPlus，DMG，德国；M2：V-Print Splint，Voco，德国）中打印（P30+DLP 打印机，Straumann，瑞士）600 个直径为 5mmx1mm 的圆盘（n=每组 25 个，共 25 个）。打印在与构建平台成 90°（A1）、45°（A2）或 0°（A3）的方向下进行。标本要么自动清洗（W1）（Straumann P Wash，Straumann，瑞士），要么手动清洗（W2）（Voco Pre-/Main-Clean 方案，Voco，德国），然后进行后聚合（P1：Cure，Straumann，瑞士；P2：Otoflash N171，Ernst Hinrichs Dental，德国）。RAW264.7 小鼠巨噬细胞暴露于标本提取物中，并通过结晶紫测定法测定细胞存活率作为细胞活力。从暴露的细胞培养物中获得的光密度值与未处理的对照（100%）归一化，总结为平均值，并进行统计分析（方差分析，α=0.05）。
细胞存活率在 9.1+/-1.3%（对齐 A2/后聚合 P2/材料 M2/清洗系统 W2）和 58.5+/-5.9%（对齐 A1/后聚合 P1/材料 M1/清洗系统 W1）之间变化。单因素方差分析显示，后聚合（p=0.000）、清洗系统（p=0.002）和材料（p=0.000）之间的平均值存在显著差异，但对齐方式（p=0.406）没有差异。采用标准化清洗和适应性后聚合，两种测试材料即使在三种打印对齐方式下均表现出最低的细胞毒性。
材料的选择以及后处理（后聚合、清洗程序）对体外细胞毒性有影响。制造过程中的对齐方式不会影响毒性。
在增材制造过程中，应匹配材料、清洗和后聚合，以减少细胞毒性。
