Exploring Needle-Like Zinc Oxide Nanostructures for Improving Dental Resin Sealers: Design and Evaluation of Antibacterial, Physical and Chemical Properties
Fabrício Mezzomo Collares, Isadora Martini García, Mariana Klein, Clarissa Cavalcanti Fatturi Parolo, Felipe Antônio Lucca Sánchez, Antônio Shigueaki Takimi, Carlos Pérez Bergmann, Susana Maria Werner Samuel, Mary Anne S. Melo, Vicente Castelo Branco Leitune
Abstract
This study aimed to evaluate the effect of needle-like zinc oxide nanostructures (ZnO-NN) on the physical, chemical, and antibacterial properties of experimental methacrylate-based dental sealers. ZnO-NN was synthesized and characterized. ZnO-NN was added to a co-monomer blend at 20, 30, and 40 wt.%. One group without ZnO-NN was used as a control. The dental resin sealers were evaluated for their flow, film thickness, water sorption, solubility, radiopacity, degree of conversion (DC), dental-sealer interface characterization via micro-Raman, and antibacterial activity. ZnO-NN presented a mean needle diameter of 40 nm and 16 m2/g of surface area. There was no difference among groups containing ZnO-NN regarding their flow. The ZnO-NN addition significantly increased the film thickness. Water sorption and solubility tests showed no difference among groups. The radiopacity increased, and DC decreased with higher concentrations of ZnO-NN. Micro-Raman suggested that ZnO-NN was in close contact with root canal dentin. Overall, the incorporation of ZnO-NN provided an antibacterial effect against Enterococcus faecalis without a significant detrimental impact on the physical and chemical functionality of the material. The use of ZnO-NN as an inorganic filler is a potential application within dental materials intended for root canal treatment.