| Autor: |
Pereira R; Department of Restorative Dentistry, Division of Operative Dentistry, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba 13414-903, SP, Brazil.; Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany., Lins RBE; School of Dentistry, Federal University of Alagoas, Lourival Melo Mota Ave, Maceió 57072-900, AL, Brazil., Lima EFS; Federal Institute of Education, Science and Technology of Goiás (IFG-Campus Uruaçu), Rua Formosa, Qd 28 e 29-Loteamento Santana, Uruaçu 76400-000, GO, Brazil., Mainardi MDCAJ; Department of Restorative Dentistry, Division of Operative Dentistry, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba 13414-903, SP, Brazil.; Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany., Stamboroski S; Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany., Rischka K; Department of Restorative Dentistry, Division of Operative Dentistry, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba 13414-903, SP, Brazil.; Department of Adhesive Bonding Technology and Surfaces, Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Wiener Straße 12, 28359 Bremen, Germany., Aguiar FHB; Department of Restorative Dentistry, Division of Operative Dentistry, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira 901, Piracicaba 13414-903, SP, Brazil. |
| Abstrakt: |
Graphene is a promising biomaterial. However, its dispersion in aqueous medium is challenging. This study aimed to modify graphene nanoparticles with L-dopa to improve the properties of experimental dental adhesives. Adhesives were formulated with 0% (control), 0.25%, 0.5%, and 0.75% of graphene, modified or not. Particle modification and dispersion were microscopically assessed. Degree of conversion was tested by Fourier-transform infrared spectroscopy. Flexural strength and modulus of elasticity were evaluated by a 3-point flexural test. Bond strength was tested by shear. To test water sorption/solubility, samples were weighed during hydration and dehydration. Antibacterial activity was tested by Streptococcus mutans colony-forming units quantification. Cytotoxicity on fibroblasts was evaluated through a dentin barrier test. The modification of graphene improved the particle dispersion. Control presented the highest degree of conversion, flexural strength, and bond strength. In degree of conversion, 0.25% of groups were similar to control. In bond strength, groups of graphene modified by L-dopa were similar to Control. The modulus of elasticity was similar between groups. Cytotoxicity and water sorption/solubility decreased as particles increased. Compared to graphene, less graphene modified by L-dopa was needed to promote antibacterial activity. By modifying graphene with L-dopa, the properties of graphene and, therefore, the adhesives incorporated by it were enhanced. |
