One of the most frequent topics I get asked about as a dentist/orthodontist is teeth bleaching. As a general dentist, I remember seeing a girl with 20+ cavities in her mouth, and, when I asked her what she wanted out of treatment, she asked me how she could bleach her teeth! True story. With that in mind, I thought I’d cover a few of the basic questions surrounding bleaching teeth.
First, there are a number of reasons why teeth change color. Tea, soda, coffee, and red wine are the most common culprits; tobacco use will almost always stain teeth. Wear of enamel over time can expose the next layer of the tooth (dentin), which is often more yellow in color than the translucent enamel. Finally, trauma to a tooth can cause the tooth to turn grey, red, or brown.
It is important to know the cause of the color change because it dramatically affects how successful bleaching, in the conventional sense, will work. For example, bleaching will work better on a more yellow hued tooth (soda stain) than it will on a brown tooth (tobacco stain). Likewise, bleaching will not work as well when a tooth has changed color because of enamel loss, where the yellowish color of the dentin is now more prominent. Teeth that are discolored due to trauma will also not respond to conventional external bleaching; they can be “bleached,” but it is called “internal bleaching,” and it requires a root canal and the expertise of a dentist. Bottom line: bleaching does not work equally well on all discolored teeth!
Second, just about all bleaching products that I’m aware of all contain one of two active ingredients: hydrogen peroxide or carbamide peroxide, but at different concentrations. The higher the concentration the quicker the bleaching effect. The lowest concentration is 6% in some Crest Whitestrips products (other Crest Whitestrips are 10% and 14% concentrated) and some “in office” bleaching can reach 40% concentration of the active ingredient. Generally speaking, “at home” bleaching products are those under 15% and “in office” products are 15-40%. So, they pretty much all work using the same active ingredients.
There are side effects to bleaching teeth! The stronger the concentration the more likely one is to experience side effects. The most common side effect is tooth sensitivity to cold; chemical burns on the gums surrounding the teeth are the next most common side effect. Chemical burns typically heal within a few days; sensitivity to cold may persist for weeks or even months.
Finally, the last thing you should know is that almost all bleaching will have a “rebound effect.” In other words, right after bleaching, your tooth may have gotten 3 shades whiter, and, in just a few days, it may darken a bit so that the end result is only 1 or 2 shades whiter. In my opinion, you are more likely to see a greater rebound with higher concentrations of whitener.
My recommendation: Because of the side effects and because of the rebound effect, I recommend that someone who is interested in bleaching their teeth start with a low-level, “at home” bleaching product like Crest Whitestrips. (Side note: Crest White Strips just received the seal of approval from the American Dental Association!) If you don’t experience sensitivity initially, stick with the Whitestrips and use them consistently over a period of time. While you won’t experience the dramatic change that comes with a 40% “in office” bleaching product, I believe you will achieve the same long term results, with less chance of side-effects, with less rebound, and for less money!
Disclaimer: I do not stand to profit in any way/shape/form from the endorsement of Crest Whitestrips. I own no stock in Crest/Oral B and I most frequently brush my teeth with Colgate toothpaste (I just like the taste better).