A key ingredient in whitening products is peroxide. But even peroxide comes in different forms. Typically, hydrogen peroxide and carbamide peroxide are the variations used in home whitening products. So what is the difference?
This simple form of the active whitening ingredient is used for in-office and professional teeth whitening. The peroxide breaks down and oxidizes the tooth enamel, causing a whitening effect. Concentrations of this chemical are lower and it works quicker because it is in the basic form. This ingredient also deteriorates quicker during storage.
This is a hydrogen peroxide that contains a urea compound. The concentrations may be higher because the urea will break down into hydrogen peroxide. It takes at least 15-20 minutes for this process to occur. Because the chemical process takes longer in this solution, it is safe to use at home because it is more forgiving to consumer error and overuse. There is less gum irritation, making it good for over the counter trays and strips.
Essentially these 2 chemicals work the same way by oxygenating tooth enamel and causing a whitening effect to take place. The strengths of the variations are different from each other, so just because one shows a higher percentage of the other does not mean it is more effective. For instance, 10% carbamide peroxide has about the same efficacy as 3% hydrogen peroxide. Lower percentages do offer less sensitivity but they will not work as fast. One study showed that 20% Carbamide Peroxide gel showed significantly more whitening than 7.5% Hydrogen peroxide during the first 14 days of use, but at the end of the study there was no significant difference between the products in regards to tooth whiteness.(1)
1. GHASSAN R. MOKHLIS, D.D.S., M.S.D., BRUCE A. MATIS, D.D.S., M.S.D., MICHAEL A. COCHRAN, D.D.S., M.S.D. and GEORGE J. ECKERT, M.A.S; A CLINICAL EVALUATION OF CARBAMIDE PEROXIDE AND HYDROGEN PEROXIDE WHITENING AGENTS DURING DAYTIME USE; JADA 2000.