I’ve tried just about every teeth whitening system there is: Crest white strips, that DIY baking soda treatment, even ZOOM! whitening—but nothing seemed to work that well. I’d notice results for a few weeks, and one day I’d catch a glimpse of my teeth in the mirror and discover I slid back down the color spectrum to where I started. Last summer, during my routine cleaning at the dentist, I mentioned my whitening frustrations to the hygienist, who was sporting a gleaming row of pearly whites. She told me I simply had to try custom bleach trays, or plastic mouthpieces made especially for your teeth.
A week later, I was back at the dentist to get my own trays made. Once they were ready, I picked them up, along with the bleaching gel (which is usually carbamide peroxide). For the next seven days, I wore them overnight—it felt a lot like wearing a retainer. Lo and behold, the trays really worked. Nearly a year later, my smile is still bright white, and I’ve only done one touch-up session.
To find out what makes custom bleach trays so much more effective than other teeth whitening systems, I turned to Dr. Jessica Emery, a cosmetic dentist and owner of Sugar Fix: A Dental Loft in Chicago. Dr. Emery also helped shed more light on the process, so that you can decide whether custom trays might be right for you.
First, you’ll make an appointment to have an impression made of your teeth. The dentist smears a mixture called silicone elastomer onto teeth, which quickly dries into a rubbery solid mold, and then plastic trays are cast from that mold.
Dr. Emery points out that while the trays are “a highly effective delivery system, it’s the gel inside the trays that whiten your teeth.” It’s important that the trays fit comfortably around your teeth and gums, so they deposit the gel right onto your teeth, and not onto your gums. A poor fit means saliva can leak in and get in the way of whitening.
You simply apply a pea-size dab of the bleaching gel to each tooth impression in the tray, and then wear the trays for about an hour or overnight (like mine), depending on the brand or type, every day for five to seven days. And then you may need touch-ups every three to six months from then on.
Results vary based on the individual, says Dr. Emery, but “show an average of seven shades whiter within two weeks.”
Dr. Emery says custom bleaching trays are “perfectly safe if used as directed, but there are still some things to be aware of.” Namely, the two biggest complaints she gets: tooth sensitivity and, more rarely, gum irritation.
People who have gum recession, cracks in their teeth, or dental restorations may be more susceptible to sensitivity while bleaching. For those patients, Dr. Emery prescribes a toothpaste with potassium nitrate, such as Sensodyne. If you’re concerned about sensitivity, just talk to your dentist about that before starting any whitening treatment.
During the bleaching process, avoid foods and drinks that are known to stain the teeth, such as coffee, red wine, and juices containing beets, carrots, and berries. If you can’t go without your favorite beverage during the bleaching period, Dr. Emery recommends using a straw, “so the staining liquid can bypass your front teeth.”
For me, custom bleach trays were a bit pricier than over-the-counter alternatives—the total was around $200 through my dentist. However, unlike with other whitening systems, I’ll have my custom trays forever. The only thing I’ll have to purchase again is the bleaching gel, which costs roughly $10–$20. And right now, I still have more than two-thirds left of my original supply.
Before you rush off to have impressions made, Dr. Emery urges you to get a routine teeth cleaning from a professional dental hygienist first. “Plaque and calculus [hardened dental plaque] often appear yellow or gray in color, so you’ll be surprised how much better your teeth will look if those superficial stains are removed,” she explains. Still, for pesky stains, Dr. Emery says custom trays do the trick. “They’re comfortable to wear, convenient, and easy to use,” she said.