Department of Prosthetic Dentistry, Faculty of Medicine, Medical Center, Center for Dental Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin and Berlin Institute of Health, Assmanshauser Str. 4-6, 14197, Berlin, Germany.
Sci Rep. 2022 May 5;12(1):7391. doi: 10.1038/s41598-022-11426-y.
Extrusion-based printing enables simplified and economic manufacturing of surgical guides for oral implant placement. Therefore, the cytotoxicity of a biocopolyester (BE) and a polypropylene (PP), intended for the fused filament fabrication of surgical guides was evaluated. For comparison, a medically certified resin based on methacrylic esters (ME) was printed by stereolithography (n = 18 each group). Human gingival keratinocytes (HGK) were exposed to eluates of the tested materials and an impedance measurement and a tetrazolium assay (MTT) were performed. Modulations in gene expression were analyzed by quantitative PCR. One-way ANOVA with post-hoc Tukey tests were applied. None of the materials exceeded the threshold for cytotoxicity (< 70% viability in MTT) according to ISO 10993-5:2009. The impedance-based cell indices for PP and BE, reflecting cell proliferation, showed little deviations from the control, while ME caused a reduction of up to 45% after 72 h. PCR analysis after 72 h revealed only marginal modulations caused by BE while PP induced a down-regulation of genes encoding for inflammation and apoptosis (p < 0.05). In contrast, the 72 h ME eluate caused an up-regulation of these genes (p < 0.01). All evaluated materials can be considered biocompatible in vitro for short-term application. However, long-term contact to ME might induce (pro-)apoptotic/(pro-)inflammatory responses in HGK.
基于挤出的打印技术可简化并降低口腔种植手术导板的制造经济成本。因此，本研究评估了一种生物聚酯（BE）和一种聚丙烯（PP）的细胞毒性，这两种材料拟用于手术导板的熔融沉积制造。为了进行比较，还通过立体光刻技术打印了一种基于甲基丙烯酸酯的医用认证树脂（ME）（每组各 18 个样本）。将人牙龈角质细胞（HGK）暴露于测试材料的浸提液中，并进行阻抗测量和四唑盐测定（MTT）。通过定量 PCR 分析基因表达的变化。采用单因素方差分析和事后 Tukey 检验。根据 ISO 10993-5：2009，没有任何一种材料的细胞毒性超过阈值（MTT 中活细胞率<70%）。反映细胞增殖的 PP 和 BE 的基于阻抗的细胞指数与对照相比几乎没有偏差，而 ME 在 72 小时后导致细胞活力降低了 45%。72 小时后 PCR 分析显示，仅 BE 引起基因表达的微小变化，而 PP 则下调了编码炎症和细胞凋亡的基因（p<0.05）。相比之下，72 小时的 ME 浸提液则导致这些基因的上调（p<0.01）。所有评估的材料在体外短期内应用都被认为具有生物相容性。然而，长期接触 ME 可能会在 HGK 中引起（促）凋亡/（促）炎反应。
