title: Addition of silver nanoparticles to composite resin: effect on physical and bactericidal properties in vitro.
abstract: The objectives of this study were to evaluate physical properties and antibacterial activity of a light-activated composite modified with silver nanoparticles. Discs were produced with unmodified resin (control group - CG) and modified resin with silver nanoparticles at two concentrations, 0.3% wt (MR03) and 0.6% wt (MR06). Streptococcus mutans and Lactobacillus acidophilus biofilms were induced in vitro by incubation of discs in a 20% sucrose medium, followed by sonication and counting of viable cells after 1, 4 and 7 days (n=9). The arithmetic roughness of all three groups was evaluated by atomic force microscopy (n=9). Compression assay was conducted in all groups to measure the compressive strength at failure and elasticity modulus (n=5). Data were subjected to ANOVA and Tukey's tests (α=0.05%). At all three time points the number of viable cells was statistically lower for MR03 and MR06 compared with CG, for both specimens. MR03 and MR06 showed no significant differences. Microscopic analysis demonstrated no significant differences for roughness among the three groups (p>0.05). The MR03 was stronger to compression than CG, and MR06 was statistically lower than CG and MR03. It was concluded that the MR03 were less conducive to biofilm growth, without compromising the strength in compression and surface roughness.
authors.affiliation: Department of Morphology and Pathology, Federal University of São Carlos, São Carlos, SP, Brazil.
authors.forename: Patrícia Bolzan Agnelli
authors.initials: PB
authors.lastname: das Neves
authors.affiliation: Department of Materials Engineering, Federal University of São Carlos, São Carlos, SP, Brazil.
authors.forename: José Augusto Marcondes
authors.initials: JA
authors.lastname: Agnelli
authors.affiliation: Department of Physics and Materials Science, Physics Institute of São Carlos, University of São Paulo, São Carlos, SP, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Kurachi
authors.affiliation: Department of Morphology and Pathology, Federal University of São Carlos, São Carlos, SP, Brazil.
authors.forename: Clovis Wesley Oliveira
authors.initials: CW
authors.lastname: de Souza
mesh_terms: D003188:Composite Resins; D066298:In Vitro Techniques; D007779:Lactobacillus acidophilus / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D012834:Silver