Dentin permeability and tubule occlusion of dentin treated with NaF and TiF4 varnishes compared to Elmex Opti-namel and Biomin F toothpastes under simulated pulp pressure.

OBJECTIVES

To investigate if a NaF varnish, a TiF4 varnish, a SnCl2+chitosan+amine fluoride/NaF toothpaste (Elmex Opti-namel) and a fluoride-calcium-phospho-silicate glass-containing toothpaste (Biomin F) reduce dentin permeability after treatment and after erosion under simulated pulp pressure, and to assess particle precipitation on dentin.

METHODS

Permeability (n = 13/group) was measured under four conditions: with (LpMin) and without smear layer (LpMax), after treatment (LpTreat), and after erosion (LpEro, 1 min, 6 % citric acid). Specimens were analyzed using laser scanning confocal microscopy (LSCM), and the number of generated particles was quantified. Data were analyzed using mixed factorial ANOVA, 2-way ANOVA and Tukey's post-hoc tests (α=0.05).

RESULTS

Smear layer removal increased the permeability of all groups in nearly 80 %. Biomin F showed significantly lower LpTreat than TiF4 (p < 0.001) and Elmex (p < 0.007), and similar results to NaF (p = 0.24). Only Biomin F presented LpTreat and LpEro significantly lower than LpMax (p < 0.01). LSCM revealed particles on dentin surface and in the tubules of all groups (LpTreat and LpEro). An irregular pattern was observed for NaF on LSCM. After treatment, the number of particles covering the dentin surface was higher for the Elmex toothpaste (p < 0.014). This number was maintained for all groups after erosion, except for the NaF varnish, where a reduction was observed (p = 0.038).

CONCLUSIONS

Only Biomin F reduced dentin permeability under simulated pulp pressure and maintained an effect after erosion. All products formed particles in the tubules and on the surface. Yet, erosion reduced the deposits for NaF varnish, but kept constant for TiF4 varnish, Elmex and Biomin F.

CLINICAL SIGNIFICANCE: Despite its lower fluoride concentration, Biomin F toothpaste effectively reduced dentin permeability under simulated pulp pressure and after an erosive challenge in vitro, suggesting its potential for managing erosion-related dentin hypersensitivity.