title: Microbicidal efficacy of thiocyanate hydrogen peroxide after adding lactoperoxidase under saliva loading in the quantitative suspension test.
abstract: OBJECTIVE
  As shown in the quantitative suspension test adding lactoperoxidase to a thiocyanate (SCN(-)) hydrogen peroxide (H(2)O(2)) combination over the physiological saliva level has significant positive antimicrobial effects to a level of totally killing Streptococcus mutans, Streptococcus sanguinis, and Candida albicans. The aim of this study was to evaluate this positive effect under human saliva loading.
  
  
  METHODS
  The bactericidal and fungicidal effect of lactoperoxidase was evaluated in a quantitative suspension test by using two test mixtures of a 2.0% thiocyanate and 1.2% hydrogen peroxide solution, one without (Group A) and one with (Group B) lactoperoxidase under saliva loading. Following the quantitative suspension tests (EN-13727/EN-13624), the growth of surviving bacteria and fungi in a nutrient broth was measured. The exposure times were restricted to 1, 3, 5, and 15 min. All statistical analyses were carried out with SPSS 11.5.
  
  
  RESULTS
  In the quantitative suspension test, the combination of thiocyanate and hydrogen peroxide showed relatively low antimicrobial effectiveness on S. mutans, S. sanguinis, and C. albicans in the presence of human saliva at measured time points in comparison to the mixture with lactoperoxidase, which showed a high bactericidal activity within 15 min (S. mutans and S. sanguinis) and fungicidal activity within 3 min (C. albicans).
  
  
  CONCLUSIONS
  The antimicrobial effectiveness of the tested thiocyanate hydrogen peroxide combination was increased significantly by adding lactoperoxidase in the quantitative suspension test under human saliva loading.
authors.affiliation: Department of Restorative Dentistry, Periodontology and Endodontology, Dental School, University of Greifswald, Rotgerber-Street 8, 17475 Greifswald, Germany. welk@uni-greifswald.de
authors.forename: A
authors.initials: A
authors.lastname: Welk
authors.forename: P
authors.initials: P
authors.lastname: Rudolph
authors.forename: J
authors.initials: J
authors.lastname: Kreth
authors.forename: Ch
authors.initials: Ch
authors.lastname: Schwahn
authors.forename: A
authors.initials: A
authors.lastname: Kramer
authors.forename: H
authors.initials: H
authors.lastname: Below
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007784:Lactoperoxidase / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology*; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D013298:Streptococcus sanguis / Q000187:drug effects* / Q000254:growth & development; D013535:Suspensions / Q000494:pharmacology; D013861:Thiocyanates / Q000494:pharmacology*
chemical_list: D000891:Anti-Infective Agents, Local; D013535:Suspensions; D013861:Thiocyanates; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase