Objectives: Eroded teeth are more susceptible to toothbrushing wear than sound teeth. We tested the hypothesis that fluoride and abrasivity of dentifrices can interact, modulating the development of erosive-abrasive lesions.
Methods: Human enamel and root dentin specimens were submitted to cycles of demineralization, remineralization and toothbrushing using six dentifrices formulated with three different abrasivity levels: low (L), medium (M) and high (H); with (+F) and without (-F) fluoride. Surface loss was quantified by optical profilometry and compared among groups (alpha=0.05).
Results: In dentin, it was ranked: L<M<H, for both +F and -F dentifrices. In enamel, +F dentifrices had similar results; however for -F formulations, M and H did not differ. Fluoride reduced surface loss in enamel, at all abrasive levels. In dentin, the same fluoride effect was observed but only for the low abrasive formulation.
Conclusions: Both fluoride and abrasivity were important modulators of enamel surface loss, while abrasivity had a higher impact than fluoride on dentin.