Effect of preservatives on reactivity of fluoride with dental enamel
Rodrigo ARTHUR Cínthia TABCHOURY Magda GIANCRISTÓFARO Altair DEL BEL CURY Jaime CURY
Resumo
Objectives: Evaluate the effect of preservatives, usually present in mouthrinse formulations, on fluoride reactivity with enamel.
Methods: Ninety-six bovine enamel slabs (4 x 4 x 2 mm), 48 sound and 48 with caries-like lesions, were longitudinally sectioned through the center. Half of each slab was kept as control and the other one subjected during 10 min to 0.05% NaF solutions containing or not 0.2% methylparaben, 0.02% propylparaben or 0.35% benzoate. Two consecutive layers of enamel were removed from all slabs, by acid etching and fluoride acid extracted was determined with specific electrode.
Results: Fluoride concentration in the half treated was subtracted from that found in the control and expressed as µg F/cm2 of enamel surface. Fluoride reactivity with sound enamel was not affected by the preservatives (P > 0.05), but methylparaben increased the reactivity of 0.05% NaF solution with carious one (P < 0.05).
Conclusion: The results suggest that methylparaben may improve fluoride reactivity with enamel, presenting caries-like lesions, but further studies are necessary to evaluate the mechanism.
Indexing terms: fluorides; dental enamel; mouthwashes.