We discussed last week that more acidic tooth whitening gels produce 
increased tooth sensitivity and are a little more harsh on your teeth in general. This concept is even more important with at-home tray whitening because trays are occasionally worn for several hours and the tooth whitening gels will be in contact with your teeth for quite some time.
You’ll notice in the table below that some of the experimentally tested pH values don’t quite match up with the pH values provided by the companies in the products’ material safety data sheets. Some of the difference is just manufacturing variation, but it also due to the break down of the active bleaching agents in storage, since carbamide peroxide and hydrogen peroxide produce alkaline byproducts after they react. Refrigeration can slow the break down of the tooth whitening gels, so it is best to store them in your refrigerator to maintain their shelf life.
Although it is best to use a tooth whitening gel that has a pH of 7 or above, many of the products with alkaline pH’s are not available in the US or have been discontinued (though I’m not sure why). The best alternatives are carbamide peroxide whitening gels that have a pH just below 7 because carbamide peroxide produces alkaline byproducts that raise the pH during whitening quickly, or tooth whitening gels close to a pH of 7 that have added calcium in their formulation like the ACP products offered by Philips Oral Healthcare.
At-Home Tray Whitening Products
| Manufacturer | Whitening Product | Whitening Agent Concentration (%) | Tested pH | MSDS pH |
|---|---|---|---|---|
| Philips | DayWhite ACP | 7.5-9.5% HP | 7.5-7.7 | ~6.2 |
| Philips | DayWhite ACP 38% Fluoride | 12.28% HP; 5.16% CP | – | 3.75-4.5 |
| Philips | NightWhite ACP | 10-22% HP | – | ~6.5 |
| Philips | NightWhite Turbo ACP (discont.) | 6.0% HP | – | ~7.5 |
| Philips | BriteSmile To Go™ Whitening Gel | 5-6% HP | – | 6.4-6.6 |
| Ultradent | Opalescence PF 20% | 20% CP | – | ~6.5 |
| Ultradent | Opalescence PF 35% | 35% CP | – | 5.6-7.2 |
| Ultradent | Opalescence PF 10% | 10% CP | 6.8 | ~6.5 |
| Ultradent | TresWhite HP PF 15% | 13% HP; 7.5% CP | – | 5.8-7.2 |
| Ultradent | TresWhite HP PF 10% | 7.8% HP; 7.5% CP | – | 5.8-7.2 |
| Evolve Dental Technologies | KOR Whitening | 10%HP | – | ~6.5 |
| Premier | Perfecta Carbamide Peroxide | 11-21% CP | – | ~6.5 |
| Premier | Perfecta Bravo | 9% HP | – | 6.3-6.7 |
| Premier | Perfecta Rev | 14% HP | – | 5.5-5.8 |
| Dentsply | NuPro White Gold | 15% CP | – | 5.7-6.5 |
| SDI | Poladay | 7.5-9.5% HP | – | 5.9-6.1 |
| SDI | Polanight | 10% CP | – | 6.11-6.9 |
| Kettenbach | Visalys 7.5 (Europe) | 7.5% HP | 10.78 | 9.5 |
| Kettenbach | Visalys 13.5 (Europe) | 13.5% HP | 6.15 | 5.8 |
| Ivoclar Vivadent | VivaStyle 10-16% | 10-16% CP | – | 5.0-6.5 |
