In Vitro Evaluation of Remineralization Potential: Whey Extract, Fluoride Varnish, and Fluoride Mouthwash on Bleached Enamel

Abstract

Background: Extrinsic discoloration is treated with bleaching which increases enamel porosity and roughness. Remineralizing materials is applied to avoid the bleaching side effects. The current study aimed to evaluate time dependent safety of bleaching materials on enamel surfaces roughness, and to assess the remineralizing potential of whey extract as a natural product and to compare it with the commercially available fluoride varnish and fluoride mouthwash after maximum bleaching time (30 min.). Methods: Extracted human incisor teeth without cracks or any enamel defects were used in this study. Teeth were cleaned and decoronated at the level of the cementoenamel junction. A nail varnish was used to cover the entire surface of the crowns of each tooth, leaving a window measuring 4 mm × 4mm. Bleaching material was applied to the enamel of all teeth specimens. The Application of bleaching material was repeated 2 more times, each time for 10 minutes, which amounted in total to 30 min. The specimens in group 1 were soaked in artificial saliva, the specimens in group 2 were soaked in whey extract, the specimens in group 3 were treated with fluoride varnish and group 4 specimens were soaked in fluoride mouthwash. Results: The mean value of the surface roughness of all the teeth specimens was increased significantly after bleaching for 10 minutes, 20 minutes and 30 minutes (p=0.000) when compared with baseline mean value. As well, there was significant direct correlation between application time of bleaching material and mean value of surface roughness (r= 0.94). There were no significant differences (p>0.05) between the specimens of the 4 groups when the mean value of surface roughness compared at baseline and after bleaching. But, after treatment, there was significant difference (p≤0.05) between the 4 groups, with the best result obtained from whey extract and fluoride varnish. Conclusions: The enamel surface roughness is significantly and directly correlated with prolonged application time of bleaching material. Remineralizing materials; whey extract, fluoride varnish and fluoride mouth wash had significantly decreased enamel surface roughness caused by bleaching. Whey extract has statistically the same effect as fluoride varnish on decreasing the surface roughness of bleached enamel surface.