Ytterbium Trifluoride as Filler for an Experimental Resin for 3D Printing

Objectives: To formulate an experimental methacrylate-based photopolymerizable resin for 3D printing with ytterbium trifluoride as filler and to evaluate mechanical, physicochemical, and biological properties.
Methods: Resin matrix was formulated with 60 wt.% UDMA, 40 wt.% TEGDMA, 1 wt.% TPO, and 0.01 wt.% BHT. Ytterbium Trifluoride was added in
concentrations of 1 (G_1%), 2 (G_2%), 3 (G_3%), 4 (G_4%), and 5 (G_5%) wt.%. One group remained without filler addition as control (G_C). The samples were designed in 3D builder software and printed using a UV-DLP 3D printer. The samples were ultrasonicated with isopropanol and UV cured for 60 minutes. The resins were tested for degree of conversion (DC), flexural strength, Knoop microhardness, softening in solvent, radiopacity, colorimetric analysis, and cytotoxicity (MTT and SRB).
Results: Post-polymerization increased the degree of conversion of all groups (p<0.05). G_2% showed the highest DC after post-polymerization. G_2% and G_C presented no difference in flexural strength (p>0.05). All groups showed a hardness reduction after solvent immersion, except G_C . No statistical difference was found in radiopacity, softening in solvent (ΔKHN%), colorimetric spectrophotometry, and cytotoxicity (MTT) (p>0.05). G_1% showed reduced cell viability for SRB assay (p<0.05).
Conclusions: It was possible to produce an experimental photopolymerizable 3D printable resin with the addition of 2% ytterbium trifluoride as filler without
compromising the mechanical, physical-chemical, and biological properties, comparable to the current provisional materials.