And while none of these dental services will transform you into Eva Longoria Parker or George Clooney, they can give you superstar attributes beyond the obvious stain removal and improved color.

Teeth whitening "makes your eyes stand out more, and it makes you look healthier," says Dr. Selena Pape, a dentist with Mortenson Family Dental in Prospect. "It's a little more of a dramatic look and, I think, a youthful look -- and it just brightens everything up."

Demand for whitening picks up at some local dental offices in the spring as residents prepare for the Derby and other special events. "Certainly around all major cultural events and the holidays, people tend to want to have a whiter smile," especially if group or family photographs are planned, says Gary Griffin, a dentist with the St. Matthews Dental Care Group.

And for Derby festivities, "people want to be at their best," Pape says. "We definitely see an upswing during that time."

If you're one of the many who plan to include a smile makeover in your Derby preparations, there are a few caveats to consider first:

• Though promotional materials boast that teeth can be lightened by several shades, results vary, Griffin says.

In general, yellowish or light-brown teeth respond better to bleaching than teeth that have become grayish, which sometimes happens because of medications, such as tetracycline, says Dr. Gary Crim, associate dean for pre-doctoral education at the University of Louisville School of Dentistry.

• Typically, a professional teeth cleaning is recommended before whitening and can be done on the same day. This could add about $100 to your bill.

• Bleaching teeth can cause temporary sensitivity, which can include tingling pain in the teeth or trouble tolerating cold beverages and ice cream, for example, Pape says.

• Your mouth should be pretty healthy. If you have "active decay, it's definitely not a good idea to bleach," because it will hurt, Crim says. Also, "decay discolors teeth, and bleaching is not going to take care of that."

• If you have gum disease, bleaching may not be for you either, depending on how severe it is, so you would need to be evaluated, says Dr. Thomas Cranfill, a dentist with Anchorage Dental.

• Bleaching won't straighten your teeth or get rid of dark-colored fillings. And past restorations, such as crowns, may no longer match your teeth after bleaching. "Anything that's not enamel is not going to whiten at all," so if you have restorations, especially in the front of your mouth, you might want to replace them after whitening, Cranfill says.

• Certain products, such as coffee, tea and red wine, as well as certain habits, such as smoking or chewing tobacco, can re-stain teeth. So, if you're going to invest in an in-office whitening treatment, this is an especially good time to kick or reduce these habits.

Here, more facts on some of the most popular whitening treatments in town:

'Chair-side' whitening (including Zoom! and Sapphire)

Appeals to: People who want quick results from a pro in one office visit; Sapphire is particularly suited to patients with sensitive teeth, Cranfill says.

Estimated cost: $300 to $500.

Pre-Derby timing: Pape (who uses the Zoom! formula in her office) recommends three to five days beforehand, mainly because for 48 hours after whitening "you're supposed to avoid anything that might be staining, like red wine or colored drinks." Otherwise, she says, "You might end up with purple teeth."

Office time: 1½ to 2 hours.

The process: With Zoom! the gum tissue is coated with a plastic barrier and gauze is placed over any exposed areas of the mouth and lips. Whitening gel is applied to the teeth, and a high-powered light is focused on the mouth to activate the gel (Sapphire uses a similar light process). Typically, there are three 15- to 20-minute treatments done in one visit with Zoom Whitening! Some people might need a fourth or might decide to stop at two, Pape says.

The results: Your teeth could get four to 12 shades lighter with chair-side bleaching, but this varies from person to person, and each brand has its own claim.

Similar results can be achieved through take-home whitening systems, but it will take longer, Crim says.

Caveats: If you have extremely sensitive teeth, "we often can't do all of the treatments; we can do a portion of them or most of them," Pape says. "People who have thin enamel or … worn teeth are going to have more sensitivity with it" than others.

A desensitizer can be applied to minimize discomfort. (Sapphire is formulated with a "desensitizing enhancer.") It also helps to take ibuprofen before the procedure, Pape says, and it can be taken afterwards if sensitivity arises. Sensitivity typically dissipates in 12 to 24 hours.

If sensitivity develops after in-office whitening, a fluoride treatment can help, says Cranfill (who uses the Sapphire formula in his practice). "It has a calming effect."

Take-home whitening

Appeals to: These dentist-supervised systems use custom-fitted mouth trays and are appropriate for someone who is self-disciplined, careful and has several days to use the system.

Cost: $200.

Pre-Derby timing: Ten days to two weeks before your event, Pape says.

Office time: Minimal (one office visit), but it may be a couple of days before your tray is ready to pick up.

How it's done: At the office, molds of the teeth are taken to create customized trays that fit "really precisely around the teeth," Pape says.

The process: After the office fitting, patients wear the trays daily at home for a prescribed period, such as a week or two. Custom trays are "very comfortable," Pape says. "They're kind of a soft, flexible plastic."

But some people don't like them in their mouths for a long period, Cranfill says.

There are many different brands of take-home whitening kits. For example, Pape offers a kit with a tray that has to be worn only a half-hour at a time for a week to 10 days. Lengthier treatment may be required in tough cases. "People who have very dark-stained teeth … might do it for 10 days and then wait and then maybe do it for another 10 days," she says.

Sapphire has a take-home system touted to whiten up to nine shades with as little as 3 minutes of wear a day for two weeks.

The results: Whitening results vary, and claims vary by brand. In general, these take-home systems "can achieve the same or better whitening (than chair-side), but it takes longer," Crim says.

Caveats: If you use too much of the gel, your gums can become irritated. Also, if you have very sensitive teeth, you might have to let your teeth "rest" for a day or two before continuing. Desensitizing toothpaste or a prescription-strength desensitizer may be needed, Pape says.

Lumineers

Appeals to: People with tough stains or who have other problems, such as uneven teeth or gaps between them, may prefer Lumineers. They are "porcelain facings or coverings that you put over the teeth to improve the shape and color," Pape says. Some people whiten their teeth first, then cover those that still need work with Lumineers or other veneers.

Cost: $1,000 per veneer.

Pre-Derby timing: "It's usually about a 2- to 2½-week turnaround time on those, so you'd have to schedule them pretty far in advance to have them by Derby," Cranfill says. Pape suggests about a month in advance, since you may need some time to adjust to the veneers, too.

Office time: Two to three visits. Expect at least an hour each visit.

The process: In the first visit, the patient is examined and impressions are made of the teeth. After the veneers have been custom-made at a lab, the patient goes back to the dentist to have the veneers placed on the teeth. The dentist may follow up later to see if fine-tuning is needed.

The results: A brighter, more perfect smile that lasts decades and doesn't look artificial, according to Lumineers' manufacturer. With veneers, patients want "a real natural look; they don't want the chalky white, piano-key, Chiclet look," Pape says. Lumineers can conceal irregularities, such as chipped or oddly shaped teeth, in addition to covering stains and discoloration. Some other brands of veneers offer similar or better results but generally require some grinding down or shaving of the underlying teeth.

Caveats: Lumineers are touted for being especially thin, and painless to place. But there's not that much difference in thickness or pain between Lumineers and more traditional veneers, Crim says. In theory, Lumineers are removable, but the underlying tooth could be damaged during removal, he says. "It's pretty well attached down to the tooth with bonding."

Problems also can result when there's an uneven margin between the regular tooth and the veneer, he says. "That catches plaque and stains, and that can cause decay." Dr Chavez is the premier Dentist in Chatworth and has been serving the San Fernando Valley for over 20 years.