Conventional and Anti-Erosion Fluoride Toothpastes: Effect on Enamel Erosion and Erosion-Abrasion

Abstract

New toothpastes with anti-erosion claims are marketed, but little is known about their effectiveness. This study investigates these products in comparison with various conventional NaF toothpastes and tin-containing products with respect to their erosion protection/abrasion prevention properties. In experiment 1, samples were demineralised (10 days, 6 × 2 min/day; citric acid, pH 2.4), exposed to toothpaste slurries (2 × 2 min/day) and intermittently stored in a mineral salt solution. In experiment 2, samples were additionally brushed for 15 s during the slurry immersion time. Study products were 8 conventional NaF toothpastes (1,400–1,490 ppm F), 4 formulations with anti-erosion claims (2 F toothpastes: NaF + KNO₃ and NaF + hydroxyapatite; and 2 F-free toothpastes: zinc-carbonate-hydroxyapatite, and chitosan) and 2 Sn-containing products (toothpaste: 3,436 ppm Sn, 1,450 ppm F as SnF₂/NaF; gel: 970 ppm F, 3,030 ppm Sn as SnF₂). A mouth rinse (500 ppm F as AmF/NaF, 800 ppm Sn as SnCl₂) was the positive control. Tissue loss was quantified profilometrically. In experiment 1, most NaF toothpastes and 1 F-free formulation reduced tissue loss significantly (between 19 and 42%); the Sn-containing formulations were the most effective (toothpaste and gel 55 and 78% reduction, respectively). In experiment 2, only 4 NaF toothpastes revealed significant effects compared to the F-free control (reduction between 29 and 37%); the F-free special preparations and the Sn toothpaste had no significant effect. The Sn gel (reduction 75%) revealed the best result. Conventional NaF toothpastes reduced the erosive tissue loss, but had limited efficacy regarding the prevention of brushing abrasion. The special formulations were not superior, or were even less effective.

Use of dentifrices to prevent erosive tooth wear: harmful or helpful?

“…35 More recently, SnF 2 dentifrices were shown to be superior in reducing dental erosion when compared with NaF dentifrices, but not combined erosion and Braz Oral Res., (São Paulo) 2014;28(Spec Iss 1):1-6 not able to increase the resistance to erosive dissolution. 22 The same was shown for calcium sodium phosphosilicate. Although it was deposited on enamel and on dentin surfaces as well, 45 this either had no preventive or repairing effect on erosion 46 or the effect against erosion was similar to that of conventional fluoride dentifrices.…”

“…11,18 On this basis, interpretation of a recent study analyzing the abrasive potential of new anti-erosion dentifrices on eroded enamel is difficult, since only RDA and not REA values were given. 22 However, RDA values of the special-formulation dentifrices were in the range of conventional dentifrices, which may account for the fact that the special formulations were not superior, and may even be less effective in preventing enamel erosion-abrasion.…”

“…20,21 However, interpretation of dentifrice abrasivity studies is challenging, particularly because the REA or RDA values obtained from different sources may vary distinctly. 22 Moreover, the relationship between enamel abrasion (REA) and dentin abrasion (RDA) is not necessarily direct, e.g., a dentifrice with a high RDA value may have a relatively low REA value and vice versa. 11,18 On this basis, interpretation of a recent study analyzing the abrasive potential of new anti-erosion dentifrices on eroded enamel is difficult, since only RDA and not REA values were given.…”

“…Different fluoride compounds have been used, such as NaF (sodium fluoride), MFP (sodium monofluoride phosphate), SnF 2 (stannous fluoride) and AmF (amine fluoride). Fluoride concentrations in dentifrices typically vary between 550 and 1450 ppm F. However, recent studies have shown a limited beneficial effect of conventional 1100 ppm F dentifrices (NaF) compared with non-fluoridated dentifrices with regard to abrasion of eroded dentin and enamel (an approximate abrasion, 22 although another study showed that SnF 2 -containing dentifrices significantly reduced erosive and abrasive wear compared to NaF dentifrices. 36 Thus, evidence available so far suggests that SnF 2 seems to be the best fluoride salt that should be incorporated into dentifrices for preventing erosion and abrasion, at least for enamel.…”

Role of arginine and fluoride in the prevention of eroded enamel: anin vitromodel

“…The calcium and phosphate present in the slurries could also contribute to establishing surface precipitates in the presence of very low amounts of F, and it can be assumed that protective effects depend on the amount, type and acid solubility of such deposits. 27 This hypothesis could partially explain the difference between microhardness and enamel wear for ESPR. Further research is necessary to elucidate the mode of action of toothpastes in enamel erosion.…”