Objective: Carbamide peroxide and hydrogen peroxide have been used as tooth whitening agents. The aim of this paper was to determine the efficiency of several enzyme-containing whitening systems. A method to determine the rate of 'in vitro' tetracycline whitening was also developed.
Methods: We determined the tetracycline whitening ability of carbamide peroxide and hydrogen peroxide, and the influence of peroxidase and lactoperoxidase on this tetracycline whitening rate.
Results: High peroxidase and lactoperoxidase concentrations increased the rate of tetracycline decoloration obtained with carbamide peroxide or hydrogen peroxide. The decoloration rate observed was lower when the glucose/glucose oxidase system was used to generate hydrogen peroxide 'in situ'. The presence of peroxidase increased the decoloration rate of extracted teeth obtained with carbamide.
Conclusions: Enzymes such as peroxidase could be used as whitening catalysts to increase the rate of tetracycline decoloration.