Dentin erosion by whitening mouthwash associated to toothbrushing abrasion: a focus variation 3D scanning microscopy study.

The aim of this study was to determine the erosive potential of hydrogen peroxide (HP) containing mouthwash on dentin assessed by Focus variation three-dimensional (3D) microscopy. Twenty dentin slabs were selected and randomly allocated into two groups (n = 10): DW--Distilled water (pH = 7.27) and HP-1.5% (pH = 3.78). Each specimen was cyclically demineralized (4 x 60 s/day, 10 days) with HP or DW and brushed 3x/day (200 g, 150 strokes--toothpaste with 1,450 ppmF as NaF). Between the challenges, the specimens were exposed to artificial saliva. Afterward, dentin loss was analyzed using focus variation 3D microscopy, and the data were submitted to unpaired t-test (alpha = 0.05). Statistically significant difference was found between the mean wear rate (mum, +/-SD) of HP (1.98 +/- 0.51) and DW (1.45 +/- 0.39). The results suggest that the use of HP-containing mouthwash associated to brushing may increase the risk of tissue loss and focus variation 3D microscopy may be used as a technique for quantifying dental wear.