Effect of vegan toothpastes on surface characteristics of human enamel after erosion-abrasion

The study evaluated the effect of vegan toothpaste on the surface and elementary constitution of enamel submitted to erosion-abrasion. Human enamel blocks (3x3mm) were submitted to in vitro erosion-abrasion cycling (1% citric acid, 4x/day). After the first and last erosive challenge, the blocks were brushed with the toothpaste: conventional fluoride-free (Bitufo), containing SnF2/SnCl2 (Oral-B Gingiva Detox, 1100 ppm F-), vegan fluoride-free (Boni Natural), or vegan with NaF (Colgate Zero, 1100 ppm F-). The control area was covered with tape, and the test area was left exposed. The tape was removed after cycling, and the blocks were evaluated for surface roughness (Ra, n=10), scanning electron microscopy (SEM, n=5), and energy dispersive spectroscopy (EDS, at%, n=5). Data analysis used split ANOVA, Kruskal-Wallis, and Dunn tests (α=0.05). Ra values in the test area were higher (p=0.01) for fluoride-free (0.389±0.09) and vegan fluoride-free (0.383±0.08) toothpastes compared to SnF2/SnCl2 (0.297±0.05) and fluoridated vegan (0.303±0.06) toothpastes. EDS analysis showed higher Na% (p=0.02) in enamel exposed to SnF2 and SnCl2 toothpaste (=0.7%) than vegan fluoride-free toothpaste (=0.5%). SEM images indicated less surface alteration in enamel exposed to SnF2/SnCl2 toothpaste. Vegan toothpaste with fluoride showed better performance in reducing the effects of surface alteration than vegan fluoride-free toothpaste; however, toothpaste containing SnF2/SnCl2 promoted the enamel surface to be less altered.