Work

In vitro cytotoxicity, oxidative stress, and inflammatory responses to 3D printing resins in human gingival fibroblasts, compared with CAD/CAM zirconia, CAD/CAM composite blocks and direct resin composites

Year: 2026

Type: article

Abstract: OBJECTIVE: This study evaluated the in vitro cytotoxicity, oxidative stress, and inflammatory responses of three 3D printed dental resins compared with CAD-CAM zirconia, CAD-CAM composite blocks, and direct resin composites, using human gingival fibroblasts. MATERIALS AND METHODS: Eight materials were tested: three 3D printed resins (SC, CC, TQ), three direct resin composites (TE, EP, VP), one CAD-CAM resin composite block (CS), and one CAD-CAM zirconia block (ZR). Specimens were prepared according to manufacturers' protocols, polished and sterilized. Material characterization included SEM surface analysis and degree of conversion (DC). Biological assessments included metabolic activity (AlamarBlue™), viability (Live/Dead™), morphology (DAPI/phalloidin), intracellular ROS levels (OxiSelect™), and IL-6 secretion (ELISA), evaluated under direct and indirect contact conditions. RESULTS: SEM revealed that all 3D printed resins exhibited a micro-hybrid structure and higher DC values (83 %-93 %) than direct resin composites (45 %-60 %). Two 3D printed resins (SC, TQ), the composite block (CS), and zirconia (ZR) demonstrated excellent cytocompatibility, while one 3D printed resin (CC) displayed reduced responses in indirect assays. ROS levels were significantly higher in all printed resins than in ZR or CS, whereas IL-6 remained moderate compared to the TE direct resin composite, which exhibited the most significant proinflammatory response. ZR displayed the most stable biological profile across all assays. SIGNIFICANCE: Within the study limits, 3D printed resins showed acceptable cytocompatibility and better performance than direct resin composites, though associated with high oxidative stress. These findings underline the importance of combining cytotoxicity and inflammatory markers when assessing the biological safety of dental materials.

Source: Dental Materials

DOI: 10.1016/j.dental.2026.01.008