title: Effect of silver nanoparticles on the physicochemical and antimicrobial properties of an orthodontic adhesive.
abstract: OBJECTIVE
  This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties.
  
  
  METHODS
  Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) test was performed after bonding metal brackets to enamel. Raman spectroscopy was used to analyze in situ the degree of conversion (DC) of the adhesive layer. The surface free energy (SFE) was evaluated after the measurement of contact angles. Growth inhibition of Streptococcus mutans in liquid and solid media was determined by colony-forming unit count and inhibition halo, respectively. One-way ANOVA was performed for SBS, DC, SFE, and growth inhibition.
  
  
  RESULTS
  The incorporation of AgNP solution decreased the SBS (p<0.001) and DC in situ (p<0.001) values. SFE decreased after addition of 0.18% and 0.33% AgNP. Growth inhibition of S. mutans in liquid media was obtained after silver addition (p<0.05).
  
  
  CONCLUSIONS
  The addition of AgNP solutions to Transbond™ XT adhesive primer inhibited S. mutans growth. SBS, DC, and SFE values decreased after incorporation up to 0.33% AgNP solution without compromising the chemical and physical properties of the adhesive.
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Materiais Odontológicos, Porto Alegre, RS, Brasil.
authors.forename: Felipe Weidenbach
authors.initials: FW
authors.lastname: Degrazia
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Materiais Odontológicos, Porto Alegre, RS, Brasil.
authors.forename: Vicente Castelo Branco
authors.initials: VC
authors.lastname: Leitune
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Materiais Odontológicos, Porto Alegre, RS, Brasil.
authors.forename: Isadora Martini
authors.initials: IM
authors.lastname: Garcia
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Bioquímica e Microbiologia Oral, Porto Alegre, RS, Brasil.
authors.forename: Rodrigo Alex
authors.initials: RA
authors.lastname: Arthur
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Materiais Odontológicos, Porto Alegre, RS, Brasil.
authors.forename: Susana Maria Werner
authors.initials: SM
authors.lastname: Samuel
authors.affiliation: - Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Laboratório de Materiais Odontológicos, Porto Alegre, RS, Brasil.
authors.forename: Fabrício Mezzomo
authors.initials: FM
authors.lastname: Collares
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002417:Cattle; D015169:Colony Count, Microbial; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000187:drug effects / Q000382:microbiology; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry*; D016910:Orthodontic Brackets / Q000382:microbiology; D010316:Particle Size; D015203:Reproducibility of Results; D033081:Shear Strength; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D003188:Composite Resins; D003738:Dental Cements; C516047:Transbond XT Light Cure Adhesive Primer; D012834:Silver