Preventive Effect of Commercial Desensitizing Toothpastes on Bovine Enamel Erosion in vitro

Abstract

This study evaluated in vitro commercial desensitizing toothpastes with respect to the prevention of erosion and explored the effect of their agents alone or in combination with fluoride. Bovine enamel blocks were randomly allocated to five groups of 20 and exposed to: Sensodyne ProNamel (1,425 ppm F as NaF, 5% KNO₃), Sensodyne Original (no fluoride, 10% SrCl₂), Colgate Sensitive (1,450 ppm F as sodium monofluorophosphate, 5% K citrate), Crest (fluoride-only toothpaste, 1,100 ppm F as NaF) and water (negative control). A second experiment was conducted with experimental dentifrices containing fluoride (NaF, 1,100 ppm F), 10% SrCl₂, 5% KNO₃or 5% K citrate alone or the latter three combined with F. The samples were submitted to four cycles, alternating demineralization (cola, 10 min) and remineralization (artificial saliva, 1 h). Before and between cyclic de- and remineralization, blocks were treated with slurries of the respective toothpastes or water (1 min). Erosive tissue loss was analyzed by profilometry. Data were analyzed by Kruskal-Wallis and Dunn’s tests (p < 0.05). The mean erosion depth (± SE, µm) was significantly less for Colgate Sensitive (0.04 ± 0.00), Sensodyne Original (0.06 ± 0.01) and Crest (0.07 ± 0.01) than for Sensodyne ProNamel (2.36 ± 0.25) or water (2.92 ± 0.24), which did not significantly differ from each other. Both F and the desensitizing agents alone reduced erosion, but no additive effect was found. In addition, the combination of F and KNO₃ did not reduce erosion. These in vitro results suggest that the presence of fluoride or desensitizing substances in toothpastes, alone or in combination, can reduce erosion of enamel, but this is not valid for all the formulations.

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

“…Thus, it is very important to carefully analyse the experimental design and the response variables used in different studies before making any inferences regarding their potential clinical effects. 14 The group in which Colgate Sensitive Pro Relief was used showed lower loss of hardness and enamel wear values, and this can be attributed to some of its components, such as arginine, calcium carbonate, sodium monofluorophosphate and titanium dioxide. This is a pioneer study involving the use of arginine, calcium carbonate and fluoride to inhibit the erosive effect on enamel.…”

“…This method has been used in numerous other studies on dental hard tissue wear due to erosion. 17,18 The in vitro model used has been successfully applied to evaluate strategies for preventing dental erosion, 14 as it allows discrimination between different treatments. According to the present design, slurries of the products were applied on the enamel surfaces for 1 minute, a condition that more closely resembles the clinical situation.…”

“…[8][9][10][11][12] However, to date, only a few studies have analysed dentifrices specifically for the prevention of erosion, and the results have been contradictory. 13,14 Thus, the aim of the present study was to evaluate the protective effect against enamel erosion, of …”

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

“…It was reported that the combination of NaF with the desensitizing agent KNO 3 impairs the effect of fluoride on the reduction of wear. 37 It is important to bear in mind that other factors such as pH, consistency and abrasivity may modulate the effect of fluoride dentifrices on dental erosion and abrasion. In a recent study it was shown that fluoride concentration and consistency influenced enamel and dentin wear, while the pH seemed to have no effect, 38 as had been previously shown for commercial dentifrices with pH ranging between 4 and 7.…”

“…2,37,43 This may be due to the interaction between NaF and KNO 3 , which reduces the bioavailability of fluoride. 37 Remineralizing agents, such as hydroxyapatite (with or without F) and Zn-carbonate hydroxyapatite, are expected to induce some mineral precipitation on enamel. 44 However, the incorporation of new hydroxyapatite into demineralized enamel is 30% reduction in wear when compared with a placebo).…”