Retention of antimicrobial activity in plaque and saliva following mouthrinse use in vivo

Caries Res. 2010;44(5):459-64. doi: 10.1159/000320267. Epub 2010 Sep 13.


The aim of this study was to determine the contribution of plaque and saliva towards the prolonged activity, also called substantivity, of three antimicrobial mouthrinses (Listerine®, Meridol®, Crest Pro Health®), used in combination with a toothpaste (Prodent Coolmint®). Volunteers brushed for 4 weeks with a toothpaste without antimicrobial claims, while during the last 2 weeks half of the volunteers used an antimicrobial mouthrinse in addition to brushing. At the end of the experimental period, plaque and saliva samples were collected 6 h after oral hygiene, and bacterial concentrations and viabilities were determined. The contribution of plaque and saliva towards substantivity was assessed by combining plaque obtained after mechanical cleaning only with plaque and saliva obtained after additional use of an antimicrobial rinse. Subsequently, resulting viabilities of the combined plaques were determined. The viabilities of plaque samples after additional rinsing with mouthrinses were lower than of plaque obtained after mechanical cleaning only, regardless of the rinse involved. Moreover, plaque collected 6 h after rinsing with antimicrobial mouthrinses contained a surplus of antimicrobial activity. Only Listerine showed decreased viability in saliva, but none of the mouthrinses showed any residual antimicrobial activity in saliva. The findings indicate that plaque left behind after mechanical cleaning contributes to the prolonged substantivity of antimicrobial mouthrinses.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Amines / metabolism
  • Amines / therapeutic use
  • Anti-Infective Agents, Local / metabolism*
  • Anti-Infective Agents, Local / therapeutic use
  • Bacteria / drug effects
  • Bacterial Load
  • Cetylpyridinium / metabolism
  • Cetylpyridinium / therapeutic use
  • Coloring Agents
  • Dental Plaque / metabolism*
  • Dental Plaque / microbiology
  • Drug Combinations
  • Female
  • Humans
  • Male
  • Microbial Viability / drug effects
  • Mouthwashes / metabolism*
  • Mouthwashes / therapeutic use
  • Salicylates / metabolism
  • Salicylates / therapeutic use
  • Saliva / metabolism*
  • Saliva / microbiology
  • Terpenes / metabolism
  • Terpenes / therapeutic use
  • Time Factors
  • Tin Fluorides / metabolism
  • Tin Fluorides / therapeutic use
  • Toothbrushing
  • Toothpastes / therapeutic use
  • Young Adult


  • Amines
  • Anti-Infective Agents, Local
  • Coloring Agents
  • Crest Pro-Health mouthrinse
  • Drug Combinations
  • Mouthwashes
  • Salicylates
  • Terpenes
  • Tin Fluorides
  • Toothpastes
  • Meridol
  • Listerine
  • Cetylpyridinium