Abstract
Introduction: Due to the COVID-19 pandemic, there has been an increased need for
antiviral 3D printable materials in dentistry. The purpose of this research is to determine the effect of mixing fumed silica (FS) and 5 different antiviral fillers (5 and 10 w/w%) on colloidal stability, viscosity, and flexural strength. Methods: Colloids consisting of five different antiviral fillers [BIOSAFE Glass and 4 different ion-releasing zeolites (Ag only, Cu only, Ag/Cu, and Ag/Zn)] were formulated with varied amounts of FS in a 3D printable resin. Flow distance of the colloids were measured as a function of time (6 months) to determine the stability of the colloids. The viscosity of each mixture was measured for 90 seconds using a rheometer at 1, 10, and 25 RPM. Flexural-strength of the polymerized colloids was determined on specimens (2mm x 2mm x 25mm) with a 3-point bend test. Results: The colloids that incorporated Ag only and Ag/Zn zeolites and BIOSAFE glass with FS remained stable over six months, but colloidal flow tests are not the optimal method of measuring stability over time. All mixtures were pseudoplastic as a function of shear rate except for the colloids containing Ag/Zn zeolites were dilatant. Addition of BIOSAFE glass and FS decreased the flexural strength of the polymerized colloid compared to the neat resin, whereas the addition of the zeolites and FS increased the flexural-strength relative to the neat resin. Conclusions: 3D-printable resins have the potential to be mixed with FS and antiviral fillers to be used for 3D printing in dentistry.