When it comes to tooth whitening with store bought strips, more isn’t necessarily better. At least that’s what researchers at the University of North Carolina at Chapel Hill found when they tested two types of whitening strips: one with 9.5 percent hydrogen peroxide and another with 10 percent hydrogen peroxide. The good news is that both whitening strips had no long term adverse side effects when used as directed.
The control group used the 10 percent hydrogen peroxide treatments for 30 minutes, while the experimental group used the 9.5 percent hydrogen peroxide for two hours. The participants applied their treatments at home and their whitening performance results were measured with digital image analysis on the third, fifth and ninth day for both groups. Although the results were certainly positive for both groups, surprisingly by day three the lower concentration H2O2 strips applied used for two hours outperformed the higher concentration strips used for less time (30 minutes).
In other words, with whitening strips, longer duration with lower concentration of hydrogen peroxide result in a greater yellow reduction and lightness when compared to shorter times with higher concentrations.
Side Effects? What Side Effects?
While no severe or permanent side effects were reported, half of the volunteers experienced some sort of temporary oral discomfort. Twenty-nine percent of the two-hour group using the 9.5 percent strips and thirteen percent of the 30-minute group with 10 percent strips experienced some degree of tooth sensitivity. Gum irritation was experienced by 21 percent of the two-hour strip group and 40 percent of the 30-minute strip group.
These side effects are actually quite common with strips. Based on this study, low concentration bleaching systems applied for a longer period of time can reduce the amount of gum irritation, but higher concentrations used for shorter periods of time seem to cause less tooth sensitivity. Personally, I have found that when I do “touch up” bleaching of my teeth they typically will get slightly sensitive during the bleaching process, but the sensitivity always goes away when I am done bleaching.
Trade-offs Come with Convenience – So what do I recommend?
In a nutshell, this UNC study reveals that when it comes to whitening strips, a higher percentage of people reported gum irritation with the higher concentrations of hydrogen peroxide when worn for shorter periods of time. So higher concentration store bought whitening strips used for shorter periods of time maybe more convenient, but may also give less spectacular results and may have a greater chance of gum irritation.
In our office, we do not use whitening strips. In our experience, the most important factor in reducing gum irritation and improving whitening performance is excellent fitting bleach trays that keep the bleach off of the gums. So in our office we make very accurate custom fitted “deep bleaching” trays for our patients, allowing them to use high concentration (30%) bleaching gels without any gum irritation. Store bought whitening strips may be cheaper, but they typically cover delicate gum tissue and cause irritation. This cannot happen with custom trays made by our staff. Our best bleaching results use a combination of ZOOM bleaching in the office, followed by custom tray bleaching at home with 30% bleaching gel. Tooth sensitivity, when encountered, is rare and easily addressed. Gum irritation is rare and also easily stopped by simply adjusting the custom bleach tray. Our results are predictable, quite spectacular and long lasting. There are very few procedures we do in our office that are this easy and have such a profound effect for our patients!
Call our Southfield dental office at 248-356-8790 and talk to me or my excellent staff for more information on how you can whiten your teeth and have the smile you’ve always wanted!
That’s all for now. Until next time,
Mark W Langberg, DDS, MAGD