title: Antimicrobial activity of silver and gold in toothpastes: A comparative analysis.
abstract: OBJECTIVE
  In this study, we compared the antimicrobial activity of identical toothpastes differing only in silver or gold nanoparticles against the activity of one of the common toothpastes containing a chemical active ingredient. We also compared the active concentrations of the toothpastes.
  
  
  METHODS
  For this study, we selected "Royal Denta" toothpastes containing silver and gold particles, and the "Blend-A-Med Complete" toothpaste containing zinc citrate as the active ingredient. We used 8 standard microorganism cultures on the basis of their individual mechanisms of protection. The antimicrobial activity of each studied preparation was evaluated at 9 concentrations.
  
  
  RESULTS
  Most effective against gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) was the "Silver Technology" – MIC was 0.004-0.0015 g/mL. Neither "Silver Technology" nor "Orange and Gold Technology" had any effect on Escherichia coli or Proteus mirabilis. Antimicrobial activity against the motile bacterium Proteus mirabilis was observed in "Silver Technology", "Orange and Gold Technology", and "Blend-A-Med Complete" – the MIC was 0.015 g/mL or lower. No antimicrobial activity against Candida albicans fungus at the studied concentrations was observed in the "Orange and Gold Technology". The toothpaste "Blend-A-Med" demonstrated the most effective antimicrobial activity - the MIC of 0.0015 g/mL and 0.015 g/mL inhibited Staphylococcus aureus and Enterococcus faecalis, respectively, and the MIC of 0.15 g/mL inhibited the growth of the bacteria Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and fungus Candida albicans.
  
  
  CONCLUSIONS
  Silver in toothpaste has a greater antimicrobial effect than gold, but its effect is still inferior to that of a chemical antimicrobial agent.
authors.forename: Jonas
authors.initials: J
authors.lastname: Junevičius
authors.forename: Juozas
authors.initials: J
authors.lastname: Žilinskas
authors.affiliation: Ukmergės g. 32-18, Kaunas, Lithuania. kcesaitis@gmail.com.
authors.forename: Kęstutis
authors.initials: K
authors.lastname: Česaitis
authors.forename: Gabrielė
authors.initials: G
authors.lastname: Česaitienė
authors.forename: Darius
authors.initials: D
authors.lastname: Gleiznys
authors.forename: Žaneta
authors.initials: Ž
authors.lastname: Maželienė
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D058491:Bacterial Load / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D002951:Citrates / Q000494:pharmacology; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006046:Gold / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008422:Materials Testing; D053758:Nanoparticles / Q000008:administration & dosage; D011513:Proteus mirabilis / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012834:Silver / Q000008:administration & dosage / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D014100:Toothpastes / Q000008:administration & dosage / Q000494:pharmacology*; D017967:Zinc Compounds / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D002951:Citrates; D014100:Toothpastes; D017967:Zinc Compounds; D012834:Silver; D006046:Gold