Types of Peroxide in Teeth Whitening Gels
Teeth whitening gels contain either hydrogen peroxide or carbamide peroxide as the active bleaching agent, with hydrogen peroxide being the direct bleaching compound and carbamide peroxide breaking down to release hydrogen peroxide. 1
Primary Active Ingredients
Hydrogen Peroxide
- Hydrogen peroxide is used directly in whitening products at concentrations ranging from 3% (over-the-counter) to 6.5% (professional strips). 2, 3
- Professional strip-based systems typically contain 5.3% to 6.5% hydrogen peroxide for at-home use. 3
- The 6.5% hydrogen peroxide strip system provides 52% more whitening efficacy than the 5.3% concentration. 3
Carbamide Peroxide
- Carbamide peroxide is the most commonly used peroxide in dentist-supervised home bleaching systems, with 10% carbamide peroxide being the standard concentration. 1, 4
- Higher concentrations of 15%, 16%, 20%, and 35% carbamide peroxide are available for faster results. 4, 5
- Carbamide peroxide breaks down to release hydrogen peroxide as the active bleaching agent. 1
- Lower concentrations (4%, 5%, and 7% carbamide peroxide) have been shown to be as effective as 10% carbamide peroxide while reducing hydrogen peroxide penetration into the pulp chamber. 6
Concentration-Based Product Categories
Professional In-Office Products
- High concentrations of peroxides (35% carbamide peroxide) are used for in-office bleaching with one-hour sessions. 5
- The 35% carbamide peroxide concentration provides significantly more lightening effect (5-9 shade tabs) compared to 16% concentration (3-5 shade tabs) after two sessions. 5
Dentist-Dispensed Home-Use Products
- Custom-tray systems with 10% carbamide peroxide remain the most common dentist-dispensed bleaching procedure. 4
- Professional strip systems with 6.5% hydrogen peroxide eliminate the need for custom trays while providing equivalent or superior results. 3
Over-the-Counter Products
- OTC products contain lower concentrations of hydrogen peroxide in various delivery systems including rinses, paint-on brushes, strips, toothpastes, and chewing gum. 4
- Most OTC products lack sufficient clinical evidence for safety and effectiveness, with studies primarily manufacturer-supported. 4
Safety Considerations
- Both hydrogen peroxide and carbamide peroxide have been used safely in oral health products and are accepted by the FDA. 1
- Lower concentrations (4-5% carbamide peroxide) reduce hydrogen peroxide penetration into the pulp chamber, potentially decreasing tooth sensitivity. 6
- Transient tooth sensitivity is the most common side effect across all peroxide concentrations. 5
Important Clinical Caveat
The evidence provided focuses on fluoride compounds and acne treatments, which are not relevant to teeth whitening. The question specifically asks about peroxide types in whitening gels, and the research literature clearly identifies hydrogen peroxide and carbamide peroxide as the two peroxide types used. 1, 4, 3