Fluoride Is Unable to Reduce Dental Erosion from Soft Drinks

Abstract

The main aim of the present study was to compare the erosive capabilities of some fruit-flavoured drinks, fresh or saturated with CaF₂, with their content of acids and with previous results from some carbonated soft drinks. The other aim was to measure and compare the rates of dissolution of CaF₂ in some carbonated and non-carbonated drinks and water. Seven commercially available fruit-flavoured drinks were diluted for drinking. Two human molars, each with two approximately 4 × 4 mm windows, were exposed continuously to 500 ml of each drink with or without prior equilibration with CaF₂ under gentle agitation for 48 h. The depths of the erosions were then measured on microradiographs made from sections. Dissolution rate of CaF₂ was measured by suspending 0.5 g of the salt in 0.5 litre of the drinks for 2, 10 and 60 min followed by solution analysis. The pH of the drinks was 2.83–3.51. The amount of NaOH required to bring pH to 5.5 ranged from 12–42 mmol/l, which is more than the amount necessary for most carbonated soft drinks. Equilibration with CaF₂ gave total fluoride concentrations of 3–8 ppm. The depths of the lesions induced by the drinks without added fluoride were 450–625 µm whilst those developed by the drinks equilibrated with CaF₂ were 350–625 µm. The dissolution of CaF₂ was faster in the carbonated drinks and in distilled water than in the non-carbonated drinks. In conclusion, non-carbonated fruit-flavoured drinks contain considerable amounts of acids which, in vitro, induce erosions in teeth similar to those induced by carbonated soft drinks. Saturation with CaF₂ reduced the in vitro development of erosions by 28% induced by drinks with pH above 3; in drinks with pH below 3, erosions were not affected by pH, despite total fluoride concentrations of up to 20 ppm.

Effect of beverages on bovine dental enamel subjected to erosive challenge with hydrochloric acid

“…Fluoride did not provide a protective effect on enamel when present in acidic carbonated beverages (25). The tested black tea contains fluoride, but other ingredients are also present in its composition, such as citric acid and phosphoric acid, which might have contributed to its negative result in terms of decrease of enamel microhardness.…”

Evaluation of some properties of fermented milk beverages that affect the demineralization of dental enamel

“…The effect of fluoride on dental erosion has been studied under various conditions with conflicting results. 19,26,27 It is possible that increasing the fluoride concentration in acidic drinks could contribute to reduce their erosive potential. However, a review paper showed that fluoride admixtures to acidic solutions in a concentration excluding toxicological side effects seem unable to arrest erosive lesions.…”

Effects of tannin-fluoride and milk-fluoride mixture on human enamel erosion from inappropriately chlorinated pool water

“…In order to protect the tooth surface completely, it has been suggested that the CaF 2 -like layer should be dense enough to build up a physical barrier, which protects the underlying enamel form acid attack, and it should be sufficiently stable against erosive dissolution (6). Although several studies have shown that application of high-concentrated fluoride can increase acid resistance of human enamel (7,29,30), a study demonstrated that fluoride does not provide protective effects against erosion from carbonated soft drinks (13).…”

“…Moreover, toothpaste fluoridation has been shown to decrease the development of erosion in situ (11,12). In contrast, several studies have demonstrated that fluorides cannot prevent dental erosion (13,14).…”