The Great Whitening Way

Testing at-home teeth-whitening products.

Tooth whiteners are primed to be the next deodorant: a once-optional form of personal hygiene that’s now simply an obligation. It’s only a matter of time because the more of us who get whitened, the grungier your unwhitened teeth will appear in contrast. Man, look at those choppers! Nasty! Aren’t you going to do something about that? There has lately been a boom in tooth-whitening techniques, both at home and in the dentist’s office. I asked St. Louis-area dentist (and frequent Slate dental correspondent) Dr. William Hartel about the various options, then tried a few for myself. Below, my findings.

At the Dentist’s Office

Dentists have been whitening teeth for years. You have two options here: 1) The dentist gives you special equipment, and you do it yourself at home, over a few weeks; or 2) the dentist does it entirely at his office, in a single day.

With Option 1, the dentist molds vinyl trays to fit your teeth. Then he gives you a prescribed gel to put in the trays. This gel will contain carbomide peroxide (which reacts with your saliva to become hydrogen peroxide) at a concentration somewhere between 10 percent and 25 percent. You go home, load the gel into the trays, wear the trays two to four hours per day for two to three weeks, and your teeth get whiter as the gel oxidizes their stains. This option has been available for more than a decade, and it works. You’ll see a difference within two days. The whole thing costs about $200 to $400, and the effects won’t wear off for several years.

Option 2 is actually the same thing but massively speeded up. The dentist puts the peroxide on your teeth and then uses a laser (or plasma arc lamp) to activate the oxidization and whiten your teeth much more quickly. You spend about an hour in the chair, and it costs between $400 and $1,000 (one Slatester paid $800 for this service). The results are the same as with Option 1, but it’s clearly more convenient. Of course, it’s more expensive, too, and you spend a full hour in the dentist’s chair with your mouth open the entire time—which can be quite unpleasant.

At Home

First of all, let’s crush the myth of “whitening toothpaste” for good. I’ve said it before; I’ll say it again: Whitening toothpastes don’t work. They don’t do anything regular toothpastes can’t do. They just cost a whole lot more (up to $7 for a tube of Rembrandt).

Toothpaste—any toothpaste—removes only surface stains. That yellowness that’s bothering you is likely not on your surface enamel (which is transparent and can be polished with toothpaste), but rather in the dentin inside your teeth (where toothpaste can’t reach). Your dentin gets yellower as you get older, even if you don’t smoke tobacco or drink coffee. It’s the yellow within this dentin that hydrogen peroxide can bleach away—when applied correctly and for an extended period.

So, can you whiten your teeth at home? Yes, but you need a hydrogen peroxide kit that mimics what the dentist does. I tried three such kits, then ranked them from worst to first.

Absolute worst: Natural White Pro Tooth Bleaching System.
I at first thought this would be the best product. It came in a fancy box with plastic dental trays, “pre-whitening toothpaste,” an “oral rinse neutralizer,” and a complicated set of steps to follow. But I soon realized this was all nonsense. The “oral rinse neutralizer” is plain old mouthwash; the “pre-whitening toothpaste” is just toothpaste. My dental expert calls this “mad scientist marketing,” wherein they convince you you’re accomplishing something by assigning lots of technical-seeming busy work. Really, all you need (or want) is the dental trays and the peroxide whitening gel.

The dental trays were a nightmare. Using the “warm and form” technique described in the instructions, I immersed the plastic trays in boiling water, then pressed them into place around my teeth. At this point, I had steaming water burning my tongue and melty plastic against my gums. Once the trays had set, I was left with mouth guards that sort of, kind of molded to my teeth. (In a dentist’s office, they make trays that fit much better.)

Next, I was to fill the trays with whitening gel and bite down on them. Another nightmare. You’re meant to wear the trays for 10-20 minutes at a time, but after 30 seconds, you begin drooling a gel-infused drool—either disgustingly down your chin or unappetizingly down your throat. You’re asked to repeat this process twice a day for one week. No thanks. And don’t think about trying to wear the trays at work or while talking on the phone. You’re a drooling mute as long as they’re in your mouth. What’s more, the concentration of hydrogen peroxide in the gel is a measly 3 percent—nowhere near what the dentist can prescribe.

I wore these trays for three days before I couldn’t take it anymore. I saw no results, despite the company’s claim that I’d notice a difference after “just a few days.” In the end, it was $24.99 utterly wasted.

Only slightly better than worst: Ultra Plus White Complete Teeth Whitening System. This one came with a “pre-whitener rinse” (mouthwash), a tooth-whitening gel, and a “patented Soft Foam mouth tray.” However, when I got home and opened up the box, there was no mouth tray. Interesting. So, after stealing a tray from the Natural White kit to use for a few days, I went back and bought a second Ultra Plus box which actually included the foam tray.

What was it like to use the Soft Foam mouth tray? Imagine, if you will, a small Nerf ball. Now, in your mind’s eye, coat this Nerf ball with sticky gel. Put the sticky Nerf ball in your mouth, and bite down on it, and stay like this for five whole minutes. The Nerf ball is sponging up your spit and getting soppy. You’re tasting Nerf. You’re unhappy. You’re meant to do this twice a day for a whole week. After each five-minute session of unhappiness, you run the Nerf ball under tap water and squeeze it dry … so you can later put it back in your mouth. This is what it’s like to use a Soft Foam mouth tray.

The Ultra Plus gel did taste a little less gaggy than the Natural White. I managed four days of treatment with it before I gave up in misery. And still no results. Like the Natural White gel, Ultra Plus White is only 3 percent hydrogen peroxide. The sole reason I rank it higher than Natural White is price: Ultra Plus costs only $14.89.

Best by far: Crest Whitestrips.
Please, I beg you—if you’re going to buy one of these kits, buy the Whitestrips. At $43.99, you pay a premium, but it’s well worth it.

Instead of using trays, the Whitestrips affix directly to your teeth, like little Band-Aids coated with peroxide gel. You wear each strip for a half-hour, then throw it away, and do this twice a day for two weeks. Crest says the results will last for “at least 6 months,” whereupon you can repeat the treatment.

I actually noticed results after a couple of days. This is likely because the Whitestrips use 6 percent hydrogen peroxide, double that of the other two chumpish whiteners. What’s more, I didn’t mind using the Whitestrips at all. No drooling! And I could talk with them in my mouth, no problem. You could even wear Whitestrips around the office if you wanted. No one would notice unless you smiled, and anyway if you smile around the office, you should stop. It makes people suspicious.

After 10 days, I checked to see if the Whitestrips had bleached my teeth, using a “Professional Tooth Shade Guide” (thoughtfully included in the Natural White instruction booklet). On the tooth shade scale from 1 (piano key which is not a sharp or flat) to 16 (kernel of corn), I had been at about a 6 before starting the treatment. (You don’t want to see what these sample teeth look like once you get past 11 or so. Just brutal.) After using Whitestrips, I’d say my teeth were at a 2 or a 3. I could actually see the difference. And I could easily compare these whitened upper teeth to my still-yellow bottom teeth, which had remained unchanged despite treatment with Natural White and Ultra Plus White.

Also, unfortunately, I could see how my upper front teeth differed from my upper back teeth. This was the only drawback I found with Whitestrips: They don’t cover your teeth all the way around. They extended about one tooth past my eyetooth on either side. So now if I smile wide, you can see my unwhitened back teeth looking a bit buttery by comparison.

Still, Whitestrips are a fantastic product. Double the peroxide concentration, ingenious delivery system. Besides, if you use all the strips for your upper teeth and you still aren’t satisfied, you can return the lower strips for your money back.

When I called the customer hot lines for the other two products, both said they would soon upgrade to the 6 percent peroxide level. But even after they catch Crest on that front, I’ll be danged if I wear one of those dental trays ever again.


If you have a lot of money that you’d like to spend on your teeth, it may be worth it to go to the dentist for whitening. The effect will be more dramatic and will last much longer. But remember, the at-home dentist treatment still means wearing trays (albeit better-fitting trays), and the in-office treatment can cost up to $1,000. If you want to spend a lot less and still see some results, you’d be extremely well-advised (by me) to go with Crest Whitestrips.