A reader who e-mailed me recently was facing a $2,000 dental procedure. She didn't have dental insurance, and even if she could afford it, the new policy wouldn't have covered the crown and root canal for at least 12 months.

As much as we might hope to buy coverage in a pinch, insurance companies are smarter than that. They might cover exams and X-rays immediately, but fillings and oral surgery usually require a one- to two-year wait.

Instead, the reader bought into a discount network and saved about $800 after purchasing an individual membership for $100 a year. The waiting period before her benefits kicked in? Three days.

It's called a discount dental plan and it's similar to buying a membership at Costco or Sam's Club. For the price of your annual membership, you get the benefit of paying lower prices on the products or services offered.

The dentists who participate in the program agree to accept a discounted fee from the plan as payment in full for their services. For example, a white filling is typically $173, but discount plan members pay $51 to $116, depending on the plan. A crown is typically $1,200, but members pay $473 to $1,000.

Annual membership fees range from $80 to $160 for an individual and $130 to $200 for a family.

One of the best ways to shop for a plan is at www.dentalplans.com. It has aggregated plans from more than 30 companies, including Aetna and Cigna. After putting in a ZIP code, you can find dentists in your area who accept the plans and what the discounted rates are for fillings, crowns, root canals and dentures.

Most people have never heard of the discount plans, probably because nearly 70 percent of Minnesotans have dental insurance, said Loren Hanson, director of marketplace activities at the Minnesota Dental Association in Minneapolis.

But even those with insurance might want to consider a dental plan if they have some unexpected big bills. Dental insurance typically has a maximum benefit per year of $1,000 to $1,200. Anyone who has already met the annual maximum and develops a new toothache is unlikely to wait until January to get it fixed.

Hanson said the MDA has had few complaints about the discount dental plans but says many patients will find that their dentist doesn't offer the discounts. About 10 percent of dentists in the Twin Cities offer them, he said.

Dental plans have a 30-day cancellation policy and no waiting periods, deductibles or maximums. Orthodontia and cosmetic procedures are included in some plans. DentalPlans.com is offering a 10 percent discount with the code "July10," but when I called several months ago I was offered a 20 percent discount after I balked about joining. Call 1-888-632-5353 or visit the website.

To determine if a new dentist is top-rated, check the July issue of Minnesota Monthly or www.minnesotamonthly.com, or the winter 2008 issue of Twin Cities Consumers' Checkbook, available in libraries.

John Ewoldt • 612-673-7633 or jewoldt@startribune.com. If you spot a deal, share it at www.startribune.com/blogs/dealspotter.