Q: I want to whiten my teeth, but would like more information about the procedure. What exactly is involved?

Ask Our Expert About Teeth Whitening

About Our Expert

Sophia C. Kladias, D.M.D., is Chair of the Department of Dental Medicine at Lehigh Valley Hospital and Health Network

• I want to whiten my teeth, but would like more information about the procedure. What exactly is involved?
• Are there some stains that don’t respond to bleaching?
• How effective are over-the-counter products?
• Are there any harmful side effects?
• How can I keep my teeth from getting more stained?

Q: I want to whiten my teeth, but would like more information about the procedure. What exactly is involved?

A: Everyone wants to have a nice smile, but over the years most people accumulate intrinsic stains which won’t brush away. These stains are in the inner layer of your teeth, called the dentin, under the top layer of enamel. Teeth whitening uses peroxide solutions that seep through the enamel into the dentin, bleaching away stains.

You can have your teeth professionally bleached at your dentist’s office. First, the dentist isolates your gums and lips from the bleaching agent, a hydrogen peroxide solution. Then the solution is applied to your teeth. Some systems use a light to activate the bleach. The procedure takes about an hour, but you may need a second application in a few weeks if your teeth are badly stained.

You can also whiten your teeth at home with a kit especially formulated for you by your dentist. This system uses a tray custom-made for your mouth from impressions of your teeth taken in the dentist’s office. Using the custom tray minimizes contact of the bleaching agent—carbamide peroxide—with your gums and other soft tissues in your mouth. You put the peroxide gel in the tray and wear it for one to three hours during each day or while sleeping. It usually takes two weeks for each arch—upper and lower jaw. Professional whitening often lasts for years. You can use the same trays just to touch up from time to time, on the advice of your dentist.

Q: Are there some stains that don’t respond to bleaching?

A: Whitening procedures are most effective on teeth with yellow stains and less so on brown ones. Unfortunately, whitening has very little impact on teeth with a grayish tone, or on stains from taking tetracycline drugs. In those cases porcelain veneers may be a good option to mask severely discolored teeth. If you had chipped teeth rebuilt with a compound that matched your tooth color, be aware that the whitening won’t affect the compound.

Q: How effective are over-the-counter products?

A: Make sure the product you choose has the American Dental Association (ADA) seal of approval and follow the manufacturer’s directions. Many people get good results with the Crest White Strips. These treatments usually last about three months. These products contain mild concentrations of bleaching agents and work best for mildly yellow teeth. If you have very yellow teeth, then you will likely need professional-type whitening. I do not recommend the kits with generic, 'one size fits all' trays because your gums may come in contact with the bleaching agent and become irritated.

Q: Are there any harmful side effects?

A: The most common side effects are tooth sensitivity and irritation to gum tissue, which usually stop after treatment is finished. Whitening is not recommended for people with overly-sensitive teeth or lots of gum recession (exposed roots). Have your teeth examined and take care of any problems before starting a whitening process. Over-using whitening products, while resulting in unnaturally white smiles, is probably not permanently harmful.

Q: How can I keep my teeth from getting more stained?

A: The tannins and polyphenols in foods like tomato sauce, grape juice, red wine, coffee and tea adhere to your teeth in less than an hour. These chemicals start to bond with plaque on your teeth and harden into tartar, making the stains almost impossible to brush away. So, brush your teeth as soon as you can after eating culprit foods like these. If you use whitening toothpaste, make sure it also has fluoride, which helps strengthen the enamel.

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