Method: Bovine dentin specimens were divided into 10 groups according to the treatment paste: 10% Ca/P; 10% Ca/P plus 900 ppm F (NaF); 20% Ca/P; 20% Ca/P plus 900 ppm F; 20% Ca/P plus 9000 ppm F; placebo (DentsCare/FGM, Brazil); placebo with 900 ppm F (DentsCare/FGM, Brazil); placebo with 9000 ppm F (DentsCare/FGM, Brazil); MI paste (CPP-ACP, Recaldent TM) and MI paste plus 900 ppm F (NaF, Recaldent TM, GC-USA). Ten specimens in each group were subjected to an erosive demineralization (Coca-cola, pH 2.6) for 90 s, 4 times a day. After erosion, the specimens were treated with one of the experimental pastes using a microbrush for 3 min. After that, the excess of the paste was removed with a cotton swab. Between the erosive challenges, the specimens were remineralized in artificial saliva (pH 6.8). Dentin loss was measured profilometrically (µm) after 5th day. Data were analyzed by Kruskal-Wallis and Dunn´s tests.
Result: The treatment pastes (10% Ca/P plus 900 ppm F: 3.33±0.23 µm; 20% Ca/P plus 900 ppm F: 3.46±0.62 µm; 20% Ca/P plus 9000 ppm F: 3.23±0.65 µm; placebo with 900 ppm F: 3.10±0.26 µm) significantly reduced dentin loss compared with placebo paste (4.70±0.44 µm).
Conclusion: The experimental calcium phosphate nanoparticles' plus F pastes seem to be a good option to prevent dentin loss by mild erosive challenges.