Description: The most common professionally dispensed whitening system is custom fitted bleaching trays made in-office. An appropriate bleaching agent is then given to the patient who is instructed on how to properly use the trays at home.8 There are a number of different bleaching agents available for use with take-home trays, so it is very important to tell your patients to always follow the manufacturer’s instructions for the product dispensed.
Take-home trays are popular for several reasons: patients are still monitored by their dental professionals, patients have control on when the desired whiteness has been achieved, patients can “touch up” as needed, and typically this option costs less than the in-office application. Ten to 30% CP or up to 14% HP products are available to use with home trays with varying wear times.
While both HP and CP are used for whitening, they have very different properties. For example, HP is considered very unstable and releases the HP in 30 to 60 minutes,13,18,19 whereas the HP in tray-delivered CP gels is slower, releasing 50% of its peroxide in the first 2-4 hours, and the remainder over the next 2-6 hours.13,18 Thus, the use of CP requires the individual to wear the trays for a longer period of time depending on the concentration of whitening agent, e.g., 2 to 8 hours (overnight) daily.7 In comparison, due to its faster release, HP products have a much shorter daily wear time ranging from 15-60 minutes.13
In addition to take-home custom trays, another professionally dispensed option is whitening strips. The white strip was initially introduced in 2000 by Crest. This flexible polyethylene strip has a pre-measured dose of HP gel. In 2001, Crest Professional Whitestrips included 6.5% HP, which were to be worn 30 minutes twice daily and were available over the counter (OTC). In 2004, Crest Whitestrips Supreme was introduced with 14% HP concentration with a low controlled dose. This higher concentration strip was designed to be professionally dispensed, however, they also are available online. Several studies show the efficacy, efficiency and safety of whitening strips.12,15,20
As for visible changes in colour using shade guide units, a meta-analysis comparing CP and HP did not reveal any significant differences in the incidence of tooth sensitivity and gingival irritation.13 Both CP and HP are recommended to be used for at least two weeks, with some products requiring up to 6 weeks to achieve maximum results.3,8 A lower concentration of the bleaching agent, such as that released in 10% CP, showed a lower risk and intensity of tooth sensitivity when compared to higher concentrations. Although some faster change in colour was seen with gels of higher concentrations, results were equivalent over time with potentially less risk of tooth sensitivity with 10% CP.21
Pros: The majority of bleaching research is on custom fitted take-home trays, and shows high degrees of safety. Patients control the results through self-administration; some professional supervision; and, less costly than in-office procedures with fewer adverse effects, such as tooth sensitivity and oral tissue irritation.7,12
Cons: Compliance is necessary; results are not as instantaneous as the in-office option; individuals can misuse and/or excessively wear trays or whitening strips leading to sensitivity.3,7 Over bleaching can result in an unnatural opaque white and loss of shine on the tooth surface.