Prevention of erosive, abrasive and erosive/abrasive tooth wear by a high-concentration fluoride dentifrice: an in vitro study

This in-vitro study compared the protective effects of a 5000-ppm fluoride dentifrice with an anti-erosive 1450-ppm formulation containing stannous chloride and chitosan under erosive, abrasive, and erosive/abrasive conditions. A total of 240 bovine enamel specimens were randomly assigned to three models: erosion followed by abrasion (EA), erosion only (E), and abrasion only (A) (n = 80 per model; n = 20 per treatment). Four treatments were tested: artificial saliva (AS), a conventional 1450-ppm NaF and SnF2 dentifrice (CT; Colgate Total), an anti-erosive 1450-ppm AmF dentifrice containing stannous chloride and chitosan (EPOS; Elmex professional Opti-Schmelz), and a 5000-ppm NaF dentifrice (CD; Colgate Duraphat). Erosive challenge consisted of 1% citric acid (pH 2.6) for 2 min. In EA, erosion was followed by brushing (1 min); in E, specimens were exposed to AS or slurry without brushing; in A, specimens were brushed without prior erosion. Brushing was performed with a manual toothbrush at 60 strokes/min under 2.5 N. Dentifrices were applied as slurries (1:6.5, artificial saliva). Ten cycles were performed with 1 h storage in artificial saliva between cycles. Enamel surface loss (µm) was measured by contact profilometry at baseline and after 10 cycles. Data were analysed using Kruskal–Wallis and Conover post-hoc tests. Significant differences were observed in EA and E (p < 0.05), but not in A (p = 0.40). In E, only EPOS reduced enamel surface loss compared with AS (p = 0.01), while CT and CD showed no significant differences. In EA, a significant difference was found only between AS and EPOS. CD did not show superior protective effects in any model. Within the limitations of this in-vitro study, increasing fluoride concentration to 5000 ppm did not enhance protection against erosive or erosive/abrasive enamel surface loss. These findings suggest that formulation-related factors, including stannous-based interactions, may be more relevant than fluoride concentration alone for preventing erosive tooth wear.