This study will analyze surface loss and color change after an erosive/abrasive cycling performed with different dentifrices with whitening, and desensitizing or only whitening claims, in comparison to their non-whitening versions, when these are available. For the surface loss analysis, 130 enamel fragments from bovine incisors (4 mm×4 mm×2 mm) will be used. They will be embedded in acrylic resin, ground flat and polished. For the color change analysis, 130 enamel fragments from bovine incisors (6 mm×6 mm×2mm) will be used. The specimens will be randomly allocated into 13 experimental groups, according to the treatments: 1. Distilled water (control); 2. Sensodyne Repair & Protect - Regular; 3. Sensodyne Repair & Protect - Branqueador; 4. Colgate Sensitive Original; 5. Colgate Sensitive Branqueador; 6. Colgate Sensitive Pró-Alívio - Regular; 7. Colgate Sensitive Pró-Alívio - Branqueador; 8. Colgate Total 12 - Regular; 9. Colgate Total 12 - Branqueador; 10. Sensodyne True White; 11. Curaprox Black is White; 12. Oral-B 3D white perfection and 13. Erosive cycling only. Specimens will be submitted to an erosive/abrasive cycling consisting of 2 min immersion in 1% citric acid solution (pH~2,4), followed by artificial saliva exposure for 60min, 6×/day, for 5 days. Brushing will be performed 2×/day, 30 min after the first and last erosive challenges, with a slurry of one of the dentifrices above mentioned and artificial saliva, in 1:3 ratio. At the end of the cycle, enamel surface loss (in ¼m) will be determined with an optical profilometer, and the color change will be determined in an ultraviolet visible light spectrophotometer, according to the system parameters CIELAB (Comission Internationale de I clairage L*, a*, b*).
News published in Agência FAPESP Newsletter about the scholarship: