Influence of the post-processing protocol on a biocompatible 3D-printed resin.

Purpose: This study aimed to evaluate the cytotoxicity of a biocompatible 3D-printed resin material for occlusal devices after post-processing with two different high-intensity UV-polymerization devices and two rinsing solvents, in the presence of human gingival fibroblasts (HGFs).

Material and methods: Sample discs from the 3D-printed resin material were printed (2 mm in height and 6 mm in diameter [N = 40]) and divided into 4 groups (n = 10) based on post-processing methods: a high-intensity UV polymerization device with isopropyl alcohol, a high-intensity UV polymerization device with a modified glycol solvent, a UV cleaning and curing unit with isopropyl alcohol, a UV cleaning and curing unit with a modified glycol solvent, and a control group cultured in DMEM medium. Different tests were performed to evaluate their cytocompatibility on HGFs: MTT assay, cell migration assay, cell cytoskeleton staining, scanning electron microscopy (SEM), and cell apoptosis and generation of intracellular reactive oxygen species (ROS). Statistical analyses were performed using one-way ANOVA and the Tukey post hoc test (α = 0.05).

Results: Cytocompatibility, MTT assay, cell migration assay, cell cytoskeleton staining, and SEM images were similar, regardless of the post-processing protocol, compared with the control group.

Conclusions: No differences were found in the cytotoxicity of the 3D-printed resin material for occlusal devices after the following post-processing methods: two different UV-polymerization devices and two rinsing solvents (isopropyl alcohol and a modified glycol solvent).