MS student, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil.
PhD student, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo (USP), São Paulo, Brazil.
J Prosthet Dent. 2024 Jul;132(1):251-259. doi: 10.1016/j.prosdent.2022.04.017. Epub 2022 Jul 19.
Three-dimensionally (3D) printed resins have become popular as a new class of materials for making interim restorations. However, little is known about how the fabrication parameters can influence biological compatibility with oral tissues.
The purpose of this in vitro study was to evaluate the effect of the postpolymerization time on the cytotoxicity of resins for printing interim restorations by using a 3D organotypic model of the oral mucosa.
Cylindrical specimens were prepared with conventional acrylic resin (AR), computer-aided design and computer-aided manufacture (CAD-CAM) resin (CC), composite resin (CR), and 2 resins for 3D printing (3DP) marketed as being biocompatible. The 3DPs were submitted to postpolymerization in an ultraviolet (UV) light chamber for 1, 10, or 20 minutes (90 W, 405 nm). Standard specimens of the materials were incubated for 1, 3, and 7 days in close contact with an organotypic model of keratinocytes (NOK-Si) in coculture with gingival fibroblasts (HGF) in a 3D collagen matrix, or directly with 3D HGF cultures. Then, the viability (Live/Dead n=2) and metabolism (Alamar Blue n=6) of the cells were assessed. Spectral scanning of the culture medium was performed to detect released components (n=6) and assessed statistically with ANOVA and the Tukey post hoc test (α=.05).
Severe reduction of metabolism (>70%) and viability of keratinocytes occurred for 3DP resin postpolymerized for 1 minute in all periods of analysis in a time-dependent manner. The decrease in cell metabolism and viability was moderate for the 3D culture of HGFs in both experimental models, correlated with the intense presence of resin components in the culture medium. The resins postpolymerized for 10 and 20 minutes promoted a mild-moderate cytotoxic effect in the period of 1 day, similar to AR. However, recovery of cell viability occurred at the 7-day incubation period. The 3DP resins submitted to postpolymerization for 20 minutes showed a pattern similar to that of CR and CC at the end of the experiment.
The cytotoxic potential of the tested 3DP resins on oral mucosa cells was influenced by postprinting processing, which seemed to have been related with the quantity of residual components leached.
三维（3D）打印树脂已成为制作临时修复体的新型材料。然而，对于制造参数如何影响与口腔组织的生物相容性知之甚少。
本体外研究旨在使用口腔黏膜三维器官型模型评估后聚合时间对用于打印临时修复体的树脂细胞毒性的影响。
用常规丙烯酸树脂（AR）、计算机辅助设计和计算机辅助制造（CAD-CAM）树脂（CC）、复合树脂（CR）和 2 种市场上声称具有生物相容性的 3D 打印树脂（3DP）制备圆柱形样本。3DP 在后聚合紫外（UV）光室内照射 1、10 或 20 分钟（90 W，405nm）。将材料的标准样本与角化细胞（NOK-Si）的器官型模型在共培养物中在 3D 胶原基质中或直接与 3D HGF 培养物密切接触孵育 1、3 和 7 天。然后，评估细胞的活力（Live/Dead n=2）和代谢（Alamar Blue n=6）。对培养物上清液进行光谱扫描以检测释放的成分（n=6），并使用 ANOVA 和 Tukey 事后检验（α=.05）进行统计学评估。
在所有分析期内，3DP 树脂后聚合 1 分钟时，细胞代谢（>70%）和活力严重下降，呈时间依赖性。在两个实验模型中，HGF 的 3D 培养物中的细胞代谢和活力下降适中，与培养基中树脂成分的强烈存在相关。后聚合 10 和 20 分钟的树脂在 1 天的孵育期内引起轻度至中度细胞毒性作用，类似于 AR。然而，细胞活力在 7 天孵育期恢复。在实验结束时，3DP 树脂后聚合 20 分钟后表现出与 CR 和 CC 相似的模式。
测试的 3DP 树脂对口腔黏膜细胞的细胞毒性潜力受后打印处理的影响，这似乎与浸出的残留成分的数量有关。
