The Effect of Erosive Products on Bleached Human Enamel

Methods: In the present study, two categories of bleaching products were used: Opalescence Boost (40% hydrogen peroxide) representing the in-office bleaching and Perl Weiss Hollywood Bleaching Weiss (10 % carbamide peroxide) representing home bleaching. Five groups of human enamel samples (n=12/group) were prepared. Two groups were bleached with Opalescence Boost (3x20 minutes) and two groups were bleaching twice per day (for 20 minutes) for 7 days with the home bleaching product. The fifth group was used as negative control and it was stored in human saliva. After the end of the bleaching procedure, one subgroup of each bleaching category was immersed three times per day (20 minutes each) for five days in an erosive soft drink (Coca Cola). Between the treatments the samples were stored in human saliva. The surface roughness of each sample was measured by using laser profilometry at four different time periods: before bleaching, after bleaching, after the end of the erosive period, and 4 weeks later.

Results: The baseline values before bleaching were all similar among the groups (p>0.05).  Both bleaching products increased enamel roughness significantly (p<0.05). The enamel roughness was higher after in-office bleaching compared to home bleaching. The statistical analysis showed that the use of soft drink after bleaching resulted in significant increase of the enamel roughness (p<0.05). The storage of the enamel samples in saliva did not have any beneficial effect on the surface roughness (p>0.05).

Conclusion: The use of erosive soft drinks after tooth bleaching have a negative effect on the enamel roughness, especially in the case of in-office bleaching products. Therefore, in the case of excessive consume of erosive soft drinks, tooth bleaching should be avoided.