Salivary Fluoride

Clinical paper summary: effect of post-brushing mouth rinse solutions on salivary fluoride retention

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

Mouth rinses are commercially available with fluoride concentrations ranging from 0 to 500 ppm (equivalent to 0.1% sodium fluoride). In a few countries, mouth rinses with sodium fluoride up to 990 ppm (equivalent to 0.2% sodium fluoride) are available. These products are generally marketed for use immediately post-brushing or at a time separate from when brushing takes place. Post-brushing mouth rinses have the capacity to enhance or diminish fluoride efficacy from toothpaste depending on fluoride level and usage pattern.1

This three-phase, randomised, cross-over study evaluated the effects of three post-brushing mouth rinses containing 0 ppm F, 225 ppm F, and 500 ppm F (equivalent to 0.05% and 0.1% sodium fluoride respectively) on salivary fluoride retention after brushing with 1450 ppm fluoride (as NaF) toothpaste and rinsing with water immediately after brushing.1

An ion-specific electrode was used to measure salivary F levels in thirty trial participants before brushing, and after brushing, rinsing with water, and then rinsing with one of the three mouth rinses. Time points evaluated after brushing were one, three, five, 10, 20, 30, 45, and 60 minutes. For saliva sample collections, subjects were asked to pool saliva in their mouths for 10 seconds before spitting out into a container for each of the time points.1


Salivary fluoride concentrations were expressed as area under the curve (AUC) over 60 minutes. The AUC0-60 means for F in saliva were 554, 252, and 20 for the 500, 225, and 0 ppm F mouth rinse groups, respectively.1


  1. Cooper L et al. Effect of post-brushing mouthwash solutions on salivary fluoride retention - study 2. J Clin Dent 2012; 23: 92–96.