Mouth rinse and fluoride

Brushing with fluoridated dentifrice is an essential part of daily oral hygiene. The use of fluoridated mouth rinse after brushing has been a debated issue within dentistry, due to the possibility of reducing the uptake of fluoride through washing out the dentifrice.

A study was reported in 2009 that investigated these issues. It investigated fluoride uptake under different circumstances. In this supervised, single-blind study, 3 oral care regimes were compared:1

  • Brushing for 1 minute with fluoridated toothpaste (0.3% NaF) followed by rinsing with water
  • Brushing for 1 minute with fluoridated toothpaste (0.3% NaF) followed by rinsing with fluoridated mouth rinse (0.02% NaF)
  • Brushing for 1 minute with fluoridated toothpaste (0.3% NaF) followed by rinsing with a non-fluoridated mouth rinse

Twenty-three adults applied each treatment once in a randomised order, separated by 1-week washout periods, and used a non-fluoridated toothpaste at home prior to and during the study.1

It can be seen from the graph that the use of a fluoridated toothpaste only, and the use of a fluoridated toothpaste followed by fluoridated mouth rinse are similar in terms of mean salivary fluoride. In other words, using a fluoridated mouth rinse after fluoridated toothpaste does not reduce fluoride levels in the mouth.1

Using a non-fluoridated mouth rinse after brushing, however, significantly reduces the fluoride in the mouth. For such patients, a 0.02% NaF mouth rinse would help maintain the level of salivary fluoride attained post brushing.1

In conclusion, this study showed that the use of a fluoridated mouth rinse can help maintain high fluoride levels post brushing;1 in other studies effective mouth rinses have also been shown to deliver a reduction in plaque and improvements in gum health.2

Salivary Fluoride

The benefits of fluoride – inhibition of demineralisation, promotion of remineralisation and prevention of caries – are widely understood by dental professionals.

Salivary Fluoride 2

From the graph, the mouth rinses with higher fluoride concentrations delivered higher salivary fluoride concentrations. The 500 ppm F mouth rinse resulted in a 2660% increase in total fluoride salivary retention over 60 minutes when compared with the 0 ppm F group, and a 120% increase when compared with the 225 ppm F group. 

Fluoride Uptake

For many patients, rinsing after brushing with dentifrice is common, whether with water or a fluoridated mouth rinse. An important question is whether rinsing with water reduces fluoride uptake, and whether this remains the case with a fluoridated mouth rinse, or whether the fluoride contained in the mouth rinse is sufficient to ensure fluoride uptake.

Consensus Statement Post-Brushing

Rinsing with water after brushing with fluoride toothpaste can reduce the benefit of fluoride toothpaste.


  1. Duckworth RM et al. Effect of rinsing with mouthwashes after brushing with a fluoridated toothpaste on salivary fluoride concentration. Caries Res 2009; 43: 391–396.
  2. Sharma NC et al. Adjunctive benefit of an essential oil containing mouthrinse in reducing plaque and gingivitis in patients who brush and floss regularly. A six-month study. J Am Dent Assoc 2004; 135: 496–504.