Innovation and Evaluations of 3D Printing Resins Modified with Zirconia Nanoparticles and Silver Nanoparticle-Immobilized Halloysite Nanotubes for Dental Restoration

Additive manufacturing technologies can be used to fabricate 3D-printed dental restorations. In this study, we evaluated the effectiveness of the functionalized loading of zirconium dioxide (ZrO2) nanoparticles and silver-nanoparticles-immobilized halloysite (HNC/Ag) nanotubes into 3D printing resins. We created 3D printing resins by adding different mass fractions of ZrO2 and HNC/Ag. First, six groups of samples containing ZrO2 were prepared, comprising five groups with different mass fractions and one control group of ZrO2 containing 1 to 16 %wt. Different mass fractions of HNC/Ag fillers were combined with the ZrO2 mixture and resin at the ideal ratio from 1 to 7.5 %wt. The mechanical characteristics of 3D resin that we assessed were the flexural strength, flexural modulus, fracture toughness, and the microhardness. Additional rates of ZrO2 4 %wt. and HNC/Ag 5 %wt. significantly increase the flexural strength, flexural modulus, and fracture toughness compared to the control group (p < 0.001). ZrO2 16 %wt. and HNC/Ag 5 %wt. were found to be significantly harder compared to the other groups (p < 0.001). The amounts of NPs that can be added to 3D printing resin modification appears to be 4 %wt., and HNC/Ag 5 %wt. can be advantageous in terms of fracture toughness, flexural strength, and flexural modulus. All additions of nanoparticles raised the resin's hardness.