Impact of toothbrushing frequency and toothpaste fluoride/abrasivity levels on incipient artificial caries lesion abrasion

To investigate the interplay among brushing frequency, dentifrice slurry abrasivity, and fluoride content on the surface loss (SL) of incipient enamel caries-like lesions. Lesions were created in 96 bovine enamel specimens (5 × 5 mm) using methylcellulose acid gel. Specimens were randomly allocated to 12 groups (n = 8), resulting from the association of three experimental factors: (1) slurry abrasive level [low: REA = 4/RDA = 69 and high: REA = 7/RDA = 208], (2) fluoride concentration [275 and 1250 ppm F as NaF], and (3) brushing frequency [1, 2 and 3× daily]. Specimens were kept in artificial saliva in between brushings and overnight. SL was determined by optical profilometry after lesion creation, 1, 3, 5, and 7 days. Data was analyzed with repeated measures ANOVA and Tukey’s tests (α = 0.05). High abrasive slurry caused significantly more SL than low with 275 ppm (p