Cytotoxicity of 3D‐printed, milled, and conventional oral splint resins to L929 cells and human gingival fibroblasts

Abstract

Objectives: Evidence on the biocompatibility of three-dimensional (3D)-printed and milled resins for oral splints is limited. This in vitro study assessed the influence of the manufacturing method on the cytotoxicity of oral splint resins on L929 cells and human gingival fibroblasts (GF1).Materials and Methods: Standardized specimens of four 3D-printed, two-milled, one-thermoformed, and one-pressed splint resin were incubated with L929 and GF1 cells for 24 h. Immunofluorescence and WST-8 assay were performed to evaluate cytotoxic effects. One-way analysis of variance and Tukey's multiple comparison test were applied with the variables "splint resin" and "manufacturing method" (p < .05).Results: Immunofluorescence showed attachment of L929 and GF1 cells to the splint resins. Irrespective of the manufacturing method, the WST-8 assay revealed significant differences between splint resins for the viability of L929 and GF1 cells.L929 cells generally showed lower viability rates than GF1 cells. The evaluation of cell viability by the manufacturing method showed no significant differences between 3D printing, milling, and conventional methods. Conclusions:The cytotoxic effects of 3D-printed, milled, and conventional oral splint resins were similar, indicating minor influence of the manufacturing method on biocompatibility. Cytotoxicity of the resins was below a critical threshold in GF1 cells. The chemical composition might be more crucial than the manufacturing method for the biocompatibility of splint resins.

Cellular responses to 3D printed dental resins produced using a manufacturer recommended printer versus a third party printer

“…Wedekind et al concluded that residual monomers and additives that eluded from 3D printed materials resulted in cytotoxicity for human gingival fibroblasts and could cause allergies and cross-reactions. 27 28 Guerrero-Gironés et al 29 found that the NextDent Ortho Rigid resin had similar cellular behavior to conventional resins, supporting the use for occlusal splints, which are also used long-term. Frasheri et al 30 concluded that 3D printed materials, which included the NextDent C&B MFH resin, affected cell proliferation and induced more unfavorable effects on gingival keratinocytes.…”

Digital manufacturing techniques and the in vitro biocompatibility of acrylic-based occlusal device materials

“…However, the MTT results showed reduced cell viability in an extract concentration-dependent manner. In a study by Bürgers et al [ 52 ], the measured cytotoxicity of the same material presented different cell viability results depending on the applied cell line, but the cell viability was not below 70%. Similarly, a slight cytotoxic effect was shown for PMMA interim material blocks [ 53 ].…”

Design of Liposome Formulations for CRISPR/Cas9 Enzyme Immobilization: Evaluation of 5-Alpha-Reductase Enzyme Knockout for Androgenic Disorders

“…Cytotoxicity studies were performed on the mouse fibroblast cell line L929 and the human PC cell line DU145 . L929 is one of the cell lines to study in vitro bioreactivity and cytotoxicity of compounds, delivery systems, and medical devices proposed by the authorities for biological safety evaluation as in the ISO 10993 (Biological evaluation of medical devices) document. , …”

“…35 L929 is one of the cell lines to study in vitro bioreactivity and cytotoxicity of compounds, delivery systems, and medical devices proposed by the authorities for biological safety evaluation as in the ISO 10993 (Biological evaluation of medical devices) document. 36,37 DU145 and L929 cells were cultured in a complete medium containing Dulbecco's modified Eagle's medium (DMEM, low glucose) with 10% fetal bovine serum (FBS), 2 mM Lglutamine, and 1% penicillin−streptomycin to avoid bacterial contamination. Then, the cells were plated in 96-well plates at a density of 5 × 10 3 cells per well in 100 μL growth media and treated with increased concentrations (50,100,200,400, 600, and 800 μg/mL based on lipid concentration) of liposome formulations for 24 h. According to the manufacturer's instructions, the percentage of viable cells was assessed using the Alamar Blue Cell Viability Assay (Thermo Fisher Scientific, USA).…”