Look for whitening specials in smaller niche publications such as neighborhood newspapers, trade papers, City Pages, (see "health" tab) and (see "professional" tab). Parkway Dental in Minneapolis has a $250 Zoom special on has a $300 Zoom special from Dr. Steve Hagerman in St. Paul. Ask about any add-ons for whitening specials. A low introductory price for new patients might not include a cleaning or an exam, but most dental insurance covers the cost of cleaning and an exam every six or 12 months.

Check lower prices online for refills of bleaching gel. Even the higher percentages available only from dentists can be found online at a savings of 50 percent or more. For example, the Nite White Excel 22 percent six-pack is $34 at Locally, dentists charge $75 or more. There are caveats, as with all online purchases. It's possible that some sellers misrepresent the product. Dau said that the shelf life of whiteners is usually a year. The website should indicate the expiration date of the product. The peroxide in the gel can become destabilized and lose effectiveness, said Dr. Matt Messina, a consumer adviser for the American Dental Association. A consumer doesn't know if the product sat in a hot truck and was compromised. For best prices, get the name of the gel you like and do a search on Google or one of the price comparison sites such as

Whiten only the teeth that show when you smile. For some people that means the front six teeth on the top and bottom. You'll save money by using less whitening gel.

Try the store brands to save money. Target, Wal-Mart, Walgreens and CVS offer store brands for about 20 percent less than name-brand whiteners. If you're not happy, keep the receipt and packaging and return them.

Ask your dentist about a higher bleach concentration of an OTC product such as Crest Whitestrips if you don't want the expense of custom trays, but want faster results.

Skip whitening toothpastes and mouthwashes. The whitening agent is not in contact with the teeth long enough to have any significant whitening effects, said Alassy.

Don't expect the usual savings at the University of Minnesota dental clinics. Anyone without insurance can often save 30 percent by having students do some of the work at the U, but its whitening prices aren't competitive. At $222 per arch plus $143 for a preliminary exam and X-rays if needed, it's more expensive than at many private dental practices.

John Ewoldt