Effect of four different opalescence tooth whitening products on enamel microhardness : scientific

Objectives: The purpose was to evaluate the effect of various Opalescence tooth-whitening products on enamel. Methods and Materials: Enamel blocks were exposed to Opalescence PF 10% Carbamide Peroxide (n=10), Opalescence PF 20% Carbamide Peroxide (n=10), Opalescence Treswhite Supreme 10% Hydrogen Peroxide (n=10) and Opalescence Quick PF 45% Carbamide Peroxide (n=10) according to the manufacturer's instructions. The control group was enamel blocks (n=10) kept in artificial saliva. The values were obtained before exposure and after the 14-days treatment period. Enamel blocks were kept in saliva between treatments. Indent marks on enamel blocks were examined using the scanning electron microscope for treatment effects. Results: All four different Opalescence products damaged enamel. The most damage was done when treated for a long period (112 hours). SEM images also showed damage to enamel by all 4 products. Opalescence with 10% and with 20% Carbamide Peroxide showed the highest damage, which also differed significantly (p<0.05) from the saliva control group (pl0.05; Tukey-Kramer Multiple comparison test). Conclusion: All 4 Opalescence products damaged enamel. Higher damage was done by the 10% carbamide peroxide and 20% carbamide peroxide products because of the much longer exposure period (112 hours in comparison to 7 hours).