Effect of brushing with two different abrasives on fluoride release by high-viscosity glass ionomer cement

The effect of brushing with two abrasive levels on the fluoride release of high-viscosity glass ionomers (GIs) was investigated. Forty-eight GI discs were fabricated and randomly assigned to one of the four groups. Treatments, performed for 30 days, included exposure to a carboxymethylcellulose (CMC) solution without fluoride (CMC-F), CMC with 275 ppm fluoride (CMC+F), CMC with fluoride plus brushing with a low abrasive slurry (relative enamel abrasivity = 4; L-ab), and CMC with fluoride plus brushing with a high abrasive slurry (relative enamel abrasivity = 7; H-ab). Fluoride release was measured after 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 days. Surface analysis was performed using optical profilometry in addition to scanning electron microscopy. Data were compared using one-way analysis of variance (α = 0.05). Fluoride release was significantly different among groups, with group H-ab showing the highest rates. Cumulative fluoride release was 10% and 30% greater in groups L-ab and H-ab than in group CMC+F. High surface roughness values were associated with H-ab as well as greater exposure of silica fillers, as observed by scanning electron microscopy. Fluoride release from conventional GIs is enhanced by brushing with high abrasive slurries.