Mechanical and antibacterial characteristics of a 3D-printed nano-titanium dioxide–hydroxyapatite dental resin-based composite

Abstract Titanium dioxide (TiO 2 ) and hydroxyapatite (HA) nanoparticles are used to improve the mechanical performance and biological integration of dental implants. One of the manufacturing methods widely used for making implants is 3D printing. In this research, a TiO 2 and HA nanoparticle composite is used as the additive to the dental resin photopolymer matrix for the stereolithography method. Herein, nanoparticles at 1, 2, 3, and 4 wt% concentrations were mixed with the resin to produce composite specimens. Hardness, tensile, impact, and wear tests were conducted to evaluate the mechanical properties of the composite material. The particle distribution and surface morphology were revealed by scanning electron microscopy. The mechanical properties of material showed fluctuating results due to particle agglomeration, micro-voids, and poor interfacial bonding of the matrix and nanoparticles during mixing and printing. Antibacterial activity of the composite material was examined by the Kirby–Bauer method using Escherichia coli and Staphylococcus aureus bacteria. The highest inhibition zone occurred around the sample with the composition 2 wt% HA and 3 wt% TiO 2 against both bacteria. For S. aureus , the inhibition zone occurred in almost all sample compositions compared to E. coli due to plasmolysis in the bacterial cell wall.