Niobium pentoxide addition to 3D printing resin-based composites.

Abstract

To formulate a 3D Resin Based Composites (RBCs) with Nb₂O₅ addition to induce mineral deposition, and evaluate its influence on mechanical, chemical, and biological properties. The experimental composite was formulated with UDMA (70 wt%), BisEMA (20 wt%), and TEGDMA (10 wt%). Barium glass (45 wt%) was used as an inorganic filler, and Nb₂O₅ was incorporated into the composites at 2 wt% and 5 wt%. 3D RBCs without Nb₂O₅ were used as a control. TPO (2 wt%) and diphenyl iodonium (1 wt%) were the photoinitiators. The degree of conversion, softening, and solvent, radiopacity, and cytotoxicity were evaluated. Flexural strength was tested following ISO 4049:2019. Mineral deposition was analyzed by Raman spectroscopy at the baseline and after 7, 14, and 28 days of artificial saliva immersion. All materials showed a degree of conversion above 90%. Softening in solvent was not affected by Nb₂O₅ addition. Radiopacity results range from 0.9 mmAl to 1mmAl, with no influence of Nb₂O_5. Cytotoxicity assays showed cell viability above 70% for all compositions. Flexural strength exceeded 100 MPa for all groups, reaching the ISO 449:2019 requirements. Mineral deposition analysis showed increased phosphate ion deposition in the 3D RBC with 2% and 5% Nb₂O₅, from early timepoints when compared to the control group. The addition of up to 5 wt% of Nb₂O₅ on an experimental 3D RBC stimulated the mineral deposition of phosphate ions on the material surfaces without reducing the chemical, mechanical, and biological properties.