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White Smile

The pH of Tray Whitening Gels

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 is also due to the breakdown of the active bleaching agents in storage since carbamide peroxide and hydrogen peroxide produce alkaline byproducts after they react. Refrigeration can slow the breakdown of 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


Embrace your ideal smile! Schedule your orthodontist appointment today and embark on the path to a healthier smile right away.

Scott Frey

Scott Frey is a renowned Orthodontist, professional speaker, and founder of the More than Smiles Movement.