title: Antibacterial, physical and mechanical properties of flowable resin composites containing zinc oxide nanoparticles.
abstract: OBJECTIVE
  The aim of this study is evaluating the antibacterial activity of resin composites containing ZnO nanoparticles against Streptococcus mutans and examining their physical and mechanical properties.
  
  
  METHODS
  The properties of flowable resin composites containing 0-5wt.% nano-ZnO are investigated using different tests:
  
  
  RESULTS
  Although the agar diffusion test reveals no significant difference between the groups, the direct contact test demonstrates that by increasing the nanoparticle content, the bacterial growth is significantly diminished (p<0.05). In the aging test, however, the antibacterial properties reduce significantly (p<0.05). The flexural strength and compressive modulus remains unchanged by incorporation of nanoparticles (p>0.05) while the compressive strength and flexural modulus significantly increase (p<0.05). The ZnO containing resins show significantly lower depth of cure (p<0.05), and higher bond strength (p<0.05). There is no significant difference between the degrees of conversion, measured by FTIR technique, of the groups (p>0.05).
  
  
  CONCLUSIONS
  Production of a dental resin composite with antibacterial activity without significant sacrificing effect on the mechanical properties is desirable in dental material science.
authors.affiliation: Pediatric Department, Shahed Dental School, Tehran, Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Tavassoli Hojati
authors.forename: Homayoon
authors.initials: H
authors.lastname: Alaghemand
authors.forename: Faeze
authors.initials: F
authors.lastname: Hamze
authors.forename: Fateme
authors.initials: F
authors.lastname: Ahmadian Babaki
authors.forename: Ramazan
authors.initials: R
authors.lastname: Rajab-Nia
authors.forename: Mohammad Bagher
authors.initials: MB
authors.lastname: Rezvani
authors.forename: Mehrnoosh
authors.initials: M
authors.lastname: Kaviani
authors.forename: Mohammad
authors.initials: M
authors.lastname: Atai
mesh_terms: D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003188:Composite Resins / Q000737:chemistry*; D019245:Compressive Strength; D055119:Elastic Modulus; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D058105:Polymerization; D033081:Shear Strength; D013295:Streptococcus mutans / Q000187:drug effects*; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003188:Composite Resins; D015034:Zinc Oxide