Interproximal plaque mass and fluoride retention after brushing and flossing--a comparative study of powered toothbrushing, manual toothbrushing and flossing

Oral Health Prev Dent. 2004;2(2):119-24.


Purpose: To determine differences in interproximal plaque mass and fluoride retention with different modes of toothbrushing and flossing.

Materials and methods: Forty-seven subjects in good health used four treatments in a four-period, randomized, crossover design: 1) manual brushing only; 2) manual brushing and daily flossing; 3) electric brushing using a rotational oscillation toothbrush; and 4) electric brushing using a sonic toothbrush. Subjects used a standard sodium fluoride dentifrice during the eight-day experimental periods and a fluoride-free dentifrice during the seven-day washout periods between treatments. Interproximal plaque samples were taken on Day 1 and on Day 8, weighed, and analyzed for fluoride content.

Results: The amount of interproximal plaque was lowest with sonic brushing, which left 43-65% less plaque than all other treatments. Manual brushing and flossing yielded less plaque than manual brushing alone and rotational oscillation brushing. Differences were statistically significant (p < 0.05) for treatment; there was no time effect on plaque mass. For fluoride retention, at Day 1 sonic brushing gave at least 54% more fluoride in the interproximal plaque than all other treatments, which was significant. All treatments demonstrated a significant increase in fluoride concentration with time except manual brushing and flossing, which showed a significant decrease. At Day 8, the fluoride concentration was significantly higher for sonic brushing than for manual brushing or rotational oscillation brushing by over 40%, and all treatments exhibited significantly greater fluoride than the manual brushing and flossing combination.

Conclusion: The mode of toothbrushing may impact the amount of plaque retained interproximally and its fluoride concentration.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cariostatic Agents / pharmacokinetics*
  • Cariostatic Agents / therapeutic use
  • Cross-Over Studies
  • Dental Devices, Home Care*
  • Dental Plaque / metabolism
  • Dental Plaque / pathology*
  • Dentifrices / therapeutic use
  • Equipment Design
  • Female
  • Fluorides / pharmacokinetics*
  • Fluorides / therapeutic use
  • Humans
  • Male
  • Sodium Fluoride / therapeutic use
  • Tooth / pathology
  • Toothbrushing / instrumentation
  • Toothbrushing / methods*


  • Cariostatic Agents
  • Dentifrices
  • Sodium Fluoride
  • Fluorides