Influence of Toothpaste Fluoride Concentration and Remineralization Time on Erosive Tooth Wear

Objectives: Remineralization of eroded dental surfaces can decrease their susceptibility to toothbrushing abrasion; however, the influence of toothpaste fluoride concentration on this protection is not known. This in-vitro study investigated how toothbrushing with toothpaste slurries (0ppm F, 1100ppm NaF, 1100ppm SnF₂, 5000ppm NaF) simulated after different remineralization times (0, 30, and 60 min) impacted the development of erosive tooth wear lesions.
Methods: Enamel and root dentin specimens were prepared from bovine incisors (n=8) and submitted to a cycling protocol including erosion, remineralization at the test times, and toothbrushing, for five days. Dental surface loss (SL, in micrometers) was determined by optical profilometry. Data were analyzed using mixed-model ANOVA and Fisher’s PLSD tests (alpha=0.05).
Results: For toothpaste comparison, 1100ppm SnF₂ had significantly less SL than 0ppm, 1100ppm NaF, and 5000ppm NaF (all p<0.05), regardless of substrate or remineralization time. 0ppm did not differ from 1100ppm NaF or 5000ppm NaF (p>0.05), except when 5000ppm NaF was used on enamel after 60min remineralization (p<0.05). 1100ppm NaF did not differ from 5000ppm NaF, except when used on dentin substrate after 30min of remineralization, or on enamel substrate after 60min (p<0.05). When comparing remineralization times, for 0ppm, regardless of substrate, and for 1100ppm SnF₂ used on enamel, 0min remineralization had significantly higher SL than 30min (p<0.05) and 60min (p<0.05); with no difference between 30 and 60min (p>0.05). For 1100ppm SnF₂ on dentin, remineralization time had no effect (p>0.05). For 1100ppm NaF and 5000ppm NaF, regardless of substrate, no clear linear trend was noted.
Conclusions: Overall, the toothpaste containing 1100ppm SnF₂ demonstrated the greatest potential for protection against toothbrushing abrasion on both enamel and dentin, which was enhanced by remineralization time for enamel, but not for dentin.