Fluoridation with mouthrinses: effects of different fluoride compounds and the solution pH. - ROS - 2011 - Tome 40 - N°3

Several mouthrinses contain active compounds intended to fight against caries by supplying fluoride to dental tissues. Among these compounds, different types of mineral fluorides such as sodium fluoride (NaF) and, more recently, organic fluorides can be found.
The objective of this study was to examine an in vitro action of different fluoride solutions and determine their fluoridation capacity on an apatitic mineral resembling dental enamel by using a standard fluoride solution for comparison.
Following to a validation phase of the analyticalmethod, synthetic hydroxyapatite discs were placed in contact with the tested mouthrinses and a control NaF solution (250 ppm F-, pH: 4.33) for 2, 4 and 6 hours.
Based on the amount of fluoride fixed on the apatitic support, the testedmouthrinses can be divided into two groups: those with the fluoridation effect much higher than and those with the fluoridation effect identical or inferior to that of control NaF solution. The most effective solutions all contain an organic fluoride compound and their superiority compared to the control solution was increasing in proportion with the increased contact time between the hydroxyapatite discs and the tested product.
The main factors explaining these differences are the acidity, which promotes fluoridation but increases the risk of superficial attack to the mineral network, and the nature of the fluoride compound. In the case of Nicomethanol hydrofluoride (fluorinol), a significant fluoridation is observed even at moderate pH.