Frequently Asked Questions

  • How does Opalescence™ teeth whitening work?

    How it works video

    Teeth whitening is the removal of stains and discolourations from the enamel and dentin. The outer layer of the tooth is enamel, and beneath the enamel is dentin. Enamel is thin and typically much lighter in colour, while dentin is darker in colour and makes up the bulk of the tooth. Enamel can be discoloured over time simply from age, but also from outside sources like coffee, tea, tobacco, and other foods and beverages. Also, as we age, our enamel thins, causing more dentin to show through, making the overall appearance of the tooth look darker.


    Opalescence whitening gels contain a powerful whitening ingredient—either carbamide peroxide or hydrogen peroxide. Peroxide gels break down into water, oxygen, and reactive oxygen molecules. These reactive oxygen molecules oxidize the bonds of discoloured stain molecules. By changing the stained molecules, the tooth appearance becomes lighter.1


  • Do I need to refrigerate Opalescence™ teeth whitening products?

    During shipping, refrigeration is not required. Once received, some Opalescence™ teeth whitening products require refrigeration, and others do not.


    Keep Opalescence Go™ teeth whitening trays and Opalescence™ PF 35% and 45% syringes stored in a refrigerated environment between 36°F (2°C) and 46°F (8°C).


    Opalescence™ PF 10%, 15%, and 20% syringes should be stored between 36°F (2°C) and 81°F (27°C), which means that these products may be stored refrigerated or at room temperature.


    If a portion of a syringe is unused following a treatment, replace the cap on the syringe and store it appropriately to be used for the next teeth whitening treatment.

  • Why should I whiten my teeth?

    People whiten their teeth for many reasons. You can bring back some of that youthful appearance with a whiter, brighter smile. Do you have a wedding or important day coming up? A whiter smile can help brighten up special occasions. Some people whiten their teeth before a job interview to get that extra boost of confidence that comes with making a great first impression.


    According to a recent survey by the American Academy of Cosmetic Dentistry, “close to one in two (48%) people believe that a smile is the most memorable feature after first meeting someone—more so than the first thing a person says (25%).” That same survey also found that “more than a third of respondents view people with a flawed smile to be less attractive (37%) and less confident (25%) than those with perfect teeth.” Smiles make a lasting impression and a bright, white, beautiful smile won’t be forgotten.

  • Is teeth whitening for everyone?

    Teeth whitening is a safe, comfortable way to get a bright, white smile. Results and treatment time may vary depending on the level of staining and whiteness desired. Crowns, bridges, fillings, and veneers will not whiten. Those with gum disease, worn enamel, cavities, and exposed roots may not be good candidates for whitening their teeth. We recommend visiting your dentist for a pre-whitening consultation so that they can help you choose the professional option that best fits your needs.

  • Should I use teeth whitening if I am pregnant, breastfeeding, or undergoing fertility treatment?

    Like with many other dental or medical treatments, people have wondered if teeth whitening during pregnancy, breastfeeding, or IVF is safe.


    Because no studies have been done regarding the safety of teeth whitening during pregnancy, the ADA suggests that "clinicians may consider recommending that teeth whitening be deferred during pregnancy."2 Most dental professionals follow this suggestion, making it the standard protocol throughout the dental community, and recommend their patients don't whiten during pregnancy or fertility treatments.

    We agree and recommend that pregnant or breastfeeding women, women undergoing fertility treatment, and patients with serious health concerns do not use teeth whiteners.

  • Are Opalescence™ whitening products tested on animals?

    Opalescence™ whitening products are cruelty-free and are not tested on animals.

  • Are Opalescence™ whitening products vegan and/or kosher?

    Yes, Opalescence™ whitening products are vegan, animal by-product free, and kosher certified.

  • Are Opalescence™ whitening products gluten-free?

    Yes, all Opalescence™ whitening products are certified gluten-free.

  • What options are available to whiten my teeth?

    Opalescence™ teeth whitening has been specially formulated and is available in many different concentrations, delivery options, and flavours. This means that you can whiten your teeth in a way that best fits your lifestyle. Whether you want to whiten your teeth with a custom tray, prefilled tray, or with an in-office teeth whitening treatment, Opalescence™ teeth whitening kits offer a professional teeth whitening option for you.

  • Will teeth whitening give me sensitive teeth?

    Tooth sensitivity is a relatively common side effect of teeth whitening. However, Opalescence whitening has not been shown to weaken tooth enamel.3,4 If sensitivity occurs, it is most often temporary and will go away when you've completed the whitening process. If you do experience tooth sensitivity, there are ways to treat it using desensitizing toothpastes and gels such as Opalescence™ Whitening Toothpaste Sensitivity Relief or UltraEZ™ desensitizing gel. Consult with your dentist to determine the best treatment for your needs.


    Find out more about treating tooth sensitivity
  • Do teeth whitening lights work?

    Lots of other in-office whitening treatments use an LED light or a laser during the whitening process. You've probably seen commercials for these kinds of teeth whiteners. Or maybe you've even seen kiosks in the mall where they use a light to whiten your teeth. Are these lights and lasers really effective, though?


    Current research shows that only hydrogen peroxide (the whitening agent used in Opalescence™ Boost in-office whitening and Opalescence Go™ tray whitening) or carbamide peroxide (the whitening agent used in Opalescence™ PF custom-tray whitening) are effective in whitening teeth. No LED teeth whitening lights are necessary with Opalescence teeth whitening, as lights do not affect the whitening results.5 In fact, some research shows that using a light for whitening can be harmful to lips and gums.6

  • Are activated charcoal teeth whitening products effective?

    There is no evidence that brushing your teeth with activated charcoal is better, safer, or more effective than standard whitening toothpaste. Charcoal leaves a mess, tends to settle at your gumline, and is difficult for a dental hygienist to remove. Although the abrasiveness of the charcoal may help remove some surface stains, you may risk abrading your enamel too much. Such damage may not be repaired. Additionally, it is impossible for charcoal to actually change the colour of your tooth. The only substance proven to whiten the colour of your enamel is activated oxygen, such as that released by the peroxide contained in Opalescence™ teeth whitening.

    If you are looking for a whitening toothpaste, we recommend Opalescence™ Whitening Toothpaste which successfully whitens by removing surface stains and is gentle enough to use daily without damaging your enamel.

  • Can I whiten my teeth after a root canal?

    Yes! Opalescence™ Endo whitening is designed specifically to whiten non-vital teeth. Consider talking to your dentist to learn more about the process for whitening a non-vital tooth.


    Find out more about our specialty teeth whitening treatments
  • Can I use Opalescence™ teeth whitening products with crowns, veneers, fillings, or other dental work?

    Yes, it is safe to use Opalescence™ whitening products on any unnatural tooth surface. If your natural teeth begin to yellow or develop stain, your goal may be to whiten those teeth so that they more closely match your existing dental work. Whitening treatments will not affect the colour or shade of a crown, veneer, implant, filling, or tooth restoration.

    We recommend abstaining from any whitening treatments for 7–10 days before a bonding procedure.7-9

  • How can I whiten my teeth overnight?

    Opalescence™ teeth whitening gives you flexible options to whiten your teeth when and where you want. Opalescence™ PF 10% teeth whitening trays allow you to whiten overnight by wearing your custom-trays while you sleep. Because the length of time needed to achieve the shade you desire will depend on your specific case, you may require more than one application of Opalescence™ PF 10% teeth whitening over multiple nights. Consult with your dentist to determine if this option is right for you.


    Find out more about Opalescence™ PF teeth whitening
  • How much does teeth whitening cost?

    The cost of teeth whitening can vary greatly depending on what you use and where you get it. While over-the-counter teeth whiteners are the least expensive, they may not be the most effective because they are not tailored to your specific needs and they may increase the risk of having sensitive teeth. Other dentist-administered teeth whitening treatments may be more expensive because of costly teeth whitening lights or lasers used in the procedure, but these accessories generally do not provide any added benefit. Opalescence™ teeth whitening offers the benefits of a dentist prescribed whitening treatment without any costly gimmicks, making it the best value. Talk to your dentist about specific costs and to determine the best whitening option for you.

  • How long do teeth whitening results last?

    Teeth whitening results are very stable, leaving you with a stunning smile long after your teeth whitening treatment is over. However, there are a few factors that can make teeth lose their luster. Things like genetics, diet, age, some medications (like tetracycline), and certain habits (like smoking) may affect the length of your whitening results. Fortunately, touch-up treatments are quick and easy, helping you get that bright, white smile back.

  • How do I get Opalescence™ teeth whitening?

    Opalescence™ teeth whitening is available from dental professionals. This ensures that you receive safe, untampered, and real Opalescence™ teeth whitening. After a routine exam to ensure you are a good candidate for teeth whitening, your dentist will provide you with the right Opalescence™ teeth whitening product for your needs.

  • 1. Kwon SR, Wertz PW. Review of the Mechanism of Tooth Whitening. J Esthet Restor Dent. 2015 Sep-Oct;27(5):240–257.
  • 2. Tooth whitening/Bleaching: Treatment Considerations for Dentists and Their Patients. ADA Council on Scientific Affairs. September 2009 (revised November 2010).
  • 3. Cadenaro M, Navarra CO, Mazzoni A, et al. An in vivo study of the effect of a 38 percent hydrogen peroxide in-office whitening agent on enamel. J Am Dent Assoc. 2010;141(4):449-454. doi:10.14219/jada.archive.2010.0198
  • 4. Cadenaro M, Breschi L, Nucci C, et al. Effect of two in-office whitening agents on the enamel surface in vivo: a morphological and non-contact profilometric study. Oper Dent. 2008;33(2):127-134. doi:10.2341/07-89
  • 5. Mondelli RF, Azevedo JF, Francisconi AC, Almeida CM, Ishikiriama SK. Comparative clinical study of the effectiveness of different dental bleaching methods - two year follow-up. J Appl Oral Sci. 2012;20(4):435–443. doi:10.1590/s1678-77572012000400008
  • 6. Bruzell EM, Johnsen B, Aalerud TN, Dahl JE, Christensen T. In vitro efficacy and risk for adverse effects of light-assisted tooth bleaching. Photochem Photobiol Sci. 2009;8(3):377–385. doi:10.1039/b813132e
  • 7. Da Silva Machado J, Cândido MS, Sundfeld RH, De Alexandre RS, Cardoso JD, Sundefeld ML. The influence of time interval between bleaching and enamel bonding. J Esthet Restor Dent. 2007;19(2):111–119. doi:10.1111/j.1708-8240.2007.00077.x
  • 8. Spyrides GM, Perdigão J, Pagani C, Araújo MA, Spyrides SM. Effect of whitening agents on dentin bonding. J Esthet Dent. 2000;12(5):264–270. doi:10.1111/j.1708-8240.2000.tb00233.x
  • 9. Unlu N, Cobankara FK, Ozer F. Effect of elapsed time following bleaching on the shear bond strength of composite resin to enamel. J Biomed Mater Res B Appl Biomater. 2008 Feb;84(2):363–368.