We all love a bright white smile! However, some of my patients have expressed concern about the long-term safety and short-term sensitivity associated with tooth whitening.
I'd like to address the 5 most commonly asked questions about teeth whitening:
1. Why do Teeth Stain?
The most common causes of stain include coffee, tea, colas, and smoking. Old fillings can also discolor teeth. Stain is more adherent to teeth covered with plaque (a combination of food debris and bacteria). Therefore, eliminating plaque with regular brushing and flossing can reduce accumulation of stain.
2. What is Tooth Whitening and How Does it Work?
Dentists offer two choices: ‘In-office’ whitening takes about an hour and may utilize a laser light to enhance the action of the whitening agent; and ‘at-home’ whitening involves wearing custom trays that fit snug on your teeth and are filled with whitening gel. ‘At home’ whitening trays can be worn several times daily or overnight. Key ingredients in whitening gels are either hydrogen peroxide or carbamide peroxide. When placed on your teeth, these gels achieve a whitening effect by ‘oxidizing’ away stain molecules. Tooth hypersensitivity is most often related to higher concentration of key ingredients but is only temporary.
3. What are the Risks of Tooth Whitening?
One side effect of Tooth Whitening is hypersensitivity. This may be caused by peroxide gel permeating into the sensitive pulp of the tooth, or creating biochemical changes which bother the tooth’s nerve. The actual whitening process of ‘oxidation’ may also contribute to hypersensitivity by dehydrating the tooth. For most patients, sensitivity is mild and lasts only a few days. Studies have not found any long-term negative effects of whitening.
There are several conditions that may predispose a person to hypersensitivity, including gum recession, clenching/grinding of teeth, acidic diet (including colas), bulimia, and acid reflux.
4. What are some helpful tips for people interested in Whitening their Teeth?
Toothpastes containing potassium nitrate containing (such as Synsodyne) can help minimize tooth hypersensitivity. Also using a whitening gel with lower peroxide concentration over a longer period of time may be more comfortable (and effective) than a fast, large dose.
5. How do Whitening Systems Compare?
Many dentists advertise that in-office laser whitening (such as ZOOM) will produce the best results; however, this is not supported by research. Both laser whitening and at-home whitening use carbamide peroxide and both can achieve similar results. In-office whitening can be done in one visit but also comes with larger cost. At-home whitening is less expensive and can be used at your leisure. Popular over-the-counter products such as Crest White Strips are placed across the teeth. While Crest contends they work, they tend to whiten only the front teeth, and it may be tricky to keep the strip from sliding off your teeth since it is not a custom fit to your unique tooth anatomy.
For any dental related questions feel free to ask!
San Francisco, California
Dr. Josh Berd, DDS
Dentist and Educator