In vitro evaluation of roughness and color change of bovine enamel submitted to tooth brushing with different whitening and desensitizing dentifrices

Abstract

The present study will evaluate surface roughness of dental enamel and of acrylic plates, also the color alteration of dental enamel, after brushing with different commercial dentifrices that contain whitening and desensitizing claims, or only whitening claim, trying to compare them with similar products without whitening claim when it is available. 100 enamel slabs (6mm × 6mm × 2mm), obtained from the crowns of bovine incisors and 100 acrylic plates (115mm× 25mm × 3 mm) will be used. The enamel slabs will be analyzed for their initial surface roughness (Ra0) with an optical profilometer, and their initial color will be evaluated by spectrophotometry. All the specimens will be randomly allocated into 10 experimental groups (n = 10), according to the dentifrice: 1. Negative control; 2. Sensodyne Repair & Protect - Regular; 3. Sensodyne Repair & Protect - Whitening; 4. Colgate Sensitive Pro-Relief - Regular; 5. Colgate Sensitive Pro-Relief - Whitening; 6. Colgate Total 12 - Regular; 7. Colgate Total 12 - Whitening; 8. Sensodyne True White; 9. Curaprox Black is White; 10. Oral-B 3D white perfection. The specimens will be then subjected to a cycle of abrasion (30.000 cycles of brushing), on a brushing machine with soft brushes (Brush machine - BIOPDI - São Carlos - São Paulo - Brazil) and a suspension of dentifrice (according to the experimental group) with artificial saliva, for enamel slabs or with water, for acrylic plates. After brushing, the specimens will be rinsed in an ultrasonic bath for 480 s, to remove the particles of the dentifrice. They will then be stored in artificial saliva at 37ºC for 24 hours. Finally, the specimens will be analyzed again for surface roughness (Ra) and color change(”E). The data obtained will be statistically analyzed, considering a level of significance of 5%.