Effect of NaF, AmF, KF gels and NaF toothpaste combined with a saliva substitute on dentin lesions in vitro.

OBJECTIVE

The aim of the present in vitro study was to evaluate the remineralizing effects of NaF, AmF, KF gels and NaF toothpaste in combination with a potentially demineralizing saliva substitute (Glandosane; pH = 5.1) being widely used in Germany.

METHODS

In each of 120 dentin specimens, three artificial lesions were created. One lesion was covered for analysis of pre-demineralization (ΔZ). Treatments during pH cycling (3 × 1 h demineralization/day [pH = 5.0] and 3 × 3 h Glandosane/day; 12 h 100%humidity) were as follows: no treatment (NT), application (5 min,2×/day) of 12.500 ppm F [pH = 6.04] (NaF-gel), 12.500 ppm F [pH = 7.34] (NaF-gel), 12.500 ppm F [pH = 5.82] (AmF-gel), 1450 ppm F [pH = 7.35] (KF-gel), and 5000 ppm F [pH = 8.14]; (NaF-TP) for 7 days (E1). Subsequently, from each specimen, one lesion was covered, while the remaining lesion was cycled for another 7 days (E2). Differences in integrated mineral loss (ΔΔZ/ΔΔZ) were calculated between values before and after pH cycling.

RESULTS

Mean (95%CI) ΔZ was 3851 (3762;3939) vol% × μm. Except for NaF-gel and NaF-TP, specimens of all other groups further demineralized. Only NaF-gel induced a significant gain in mineral content (p ≤ 0.004; paired t test). Significant differences in the change of mineral loss were found between NT and all fluoride groups for both ΔΔZ and for ΔΔZ (p < 0.05, Bonferroni post hoc test). However, only NaF-gel and NaF-TP induced remineralization.

CONCLUSION

Under the in vitro conditions chosen, all fluoride agents could significantly hamper the adverse effects of a demineralizing saliva substitute.

CLINICAL SIGNIFICANCE

In combination with a demineralizing saliva substitute, slight mineral gain was only observed for neutral NaF-gel and 5000 ppm F toothpaste.