Objectives

The aim of this study was to assess the post curing monomer release of resins applicable for 3D printing of surgical implant guides in dependency of printing technique and storing media using high performance liquidchromatography.

Material and methods

Specimens of Nextdent SG, Freeprint Splint, Fotodent Guide, 3Delta Guide, and V-print SG (n = 4) were additively manufactured with the corresponding DLP/SLA printing devices (Rapidshape D20II, Form2, Solflex350). Postprocessing was done according to the manufacturer’s specifications. Subsequently, samples were eluted in methanol and water for 3 days and analyzed with gas chromatography/mass spectrometry (GC/MS).

Results

A total of twelve different substances released from the tested resin materials. The highest eluted concentration for MMA in methanol was 20.27 ± 8.60 μg/mL followed by 12.66 ± 3.38 μg/mL of HPMA. HEMA was found at concentration of 11.17 ± 2.43 μg/mL in methanol and 1.15 ± 0.11 μg/mL in water. TPGDA and TEGDMA reached maximum concentration in methanol of 4.29 ± 0.54 μg/mL and 5.07 ± 0.93 μg/mL and in water of 0.79 ± 0.19 μg/mL and 0.36 ± 0.14 μg/mL, respectively. Significant difference was found for the material Nextdent SG manufactured on SLA and DLP printing device for THFMA (p = 0.041), TEGDMA (p = 0.026), TPGDA (p = 0.05) and EGDMA (p = 0.06). The amount of monomers released into water did not reach the detection threshold for V-print SG.

Significance

The study revealed significant influence of the printing technique and resin material on the elution of monomers. The elution in methanol and water was significantly different. While the relative amount of eluted monomers from 3D printed guides is comparable to conventional direct composites and below toxic relevant concentrations, the absolute amount of monomer can rise in a clinic situation due to the size of the guides.

中文翻译：

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从使用不同3D打印设备制造的外科手术导向树脂中释放单体。

目标

这项研究的目的是评估依赖于打印技术和使用高效液相色谱法存储介质的3D打印外科植入物导向器的树脂的后固化单体释放。

材料与方法

Nextdent SG，Freeprint Splint，Fotodent Guide，3Delta Guide和V-print SG（n = 4）的样品是使用相应的DLP / SLA打印设备（Rapidshape D20II，Form2，Solflex350）相加制造的。根据制造商的规格进行后处理。随后，将样品在甲醇和水中洗脱3天，并用气相色谱/质谱（GC / MS）分析。

结果

从测试的树脂材料中总共释放出十二种不同的物质。甲醇中MMA的最高洗脱浓度为20.27±8.60μg/ mL，然后是12.66±3.38μg/ mL的HPMA。发现HEMA在甲醇中的浓度为11.17±2.43μg/ mL，在水中为1.15±0.11μg/ mL。TPGDA和TEGDMA在甲醇中的最大浓度分别为4.29±0.54μg/ mL和5.07±0.93μg/ mL，在水中的最大浓度分别为0.79±0.19μg/ mL和0.36±0.14μg/ mL。发现在SLA和DLP印刷设备上制造的Nextdent SG材料在THFMA（p = 0.041），TEGDMA（p = 0.026），TPGDA（p = 0.05）和EGDMA（p = 0.06）方面存在显着差异。释放到水中的单体数量未达到V-print SG的检测阈值。

意义

该研究揭示了印刷技术和树脂材料对单体洗脱的重大影响。在甲醇和水中的洗脱显着不同。尽管从3D打印的指南中洗脱出的单体的相对量与常规直接复合材料相当，并且低于有毒相关浓度，但由于指南的尺寸，单体的绝对量在临床情况下可能会增加。