title: Antibacterial activity of glass ionomer cement modified by zinc oxide nanoparticles.
abstract: This study evaluated the antibacterial activity of zinc oxide nanoparticles incorporated into self-cured glass ionomer cement (GIC) and light-cured resin-reinforced GIC on Streptococcus mutans biofilm. The GICs, Fuji II (GC America) and Fuji II LC (GC America), were incorporated with nanoparticles at concentrations of 0%, 1%, and 2% by weight, and the biofilm maturation time was one and seven days. Circular specimens of each GIC type were prepared. The antibacterial activity was evaluated by determining the number of colony forming units of S. mutans strain per milliliter. Morphology of the biofilm was analyzed by scanning electron microscopy (SEM). The data obtained for each GIC were analyzed by two-way ANOVA (α = 5%). For chemically activated GIC, no significant difference was observed in relation to the time of biofilm maturation (p = 0.744), concentration of nanoparticles (p = 0.966), and their interaction (p = 0.800). The results from analysis of GIC modified by light-polymerized resin showed that only of the maturing time significantly affected the number of adhered cells on the biofilm (p = 0.034, F = 4.778). The more mature the biofilm, higher the number of cells. SEM analysis showed no change in cell morphology in relation to the type of GIC, maturation time, and nanoparticles concentration. We conclude that the inclusion of zinc oxide nanoparticles at concentrations of 1% and 2% by weight into the GICs evaluated here, did not promote their antimicrobial activity against S. mutans.
authors.affiliation: Department of Social Dentistry, Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Patrícia Petromilli Nordi Sasso
authors.initials: PPNS
authors.lastname: Garcia
authors.affiliation: Department of Social Dentistry, Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Mariana Florian Bell
authors.initials: MFB
authors.lastname: Cardia
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Renata Serignoli
authors.initials: RS
authors.lastname: Francisconi
authors.affiliation: Department of Social Dentistry, Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Lívia Nordi
authors.initials: LN
authors.lastname: Dovigo
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Denise Madalena Palomari
authors.initials: DMP
authors.lastname: Spolidório
authors.affiliation: Department of Restorative Dentistry Araraquara School of Dentistry, University of São Paulo State, São Paulo, Brazil.
authors.forename: Alessandra Nara
authors.initials: AN
authors.lastname: de Souza Rastelli
authors.affiliation: Department of General Dentistry, Stony Brook School of Dental Medicine, Stony Brook, New York.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Botta
keywords: SEM; antibacterial; biofilms; glass ionomer cement; microscopy; nanoparticles; zinc oxide