Dentists Say This LED Whitening Kit is Gentler on Gums Than Gels and Strips—So I Tried It (2024)

My love for drinking black coffee makes it difficult for me to maintain a pearly white smile. While teeth-whitening kits are readily available at almost every supermarket and drugstore you can shop at, I haven't had the best luck using them. Not because the product is ineffective, but my gums burn the second the whiting gel is applied to my teeth.

It's a pretty common problem for folks trying to whiten their teeth at home, and it's why products like the Colgate Optic White ComfortFit Teeth-Whitening Kit (Normally $50, now $42) have become such a popular alternative. The kit relies on LED light and "purple wavelength technology" to whiten teeth, a process that is reportedly gentler on sensitive gums.

Tired of coffee-stained chompers, I decided to give the Colgate Optic White ComfortFit Teeth-Whitening Kit a whirl. What arrived was a futuristic-looking mouthpiece, a gel-whitening pen, and handful of charging cables. My first thought was, "How, exactly, does this work?" Thankfully, there are dentists to answer that.

How does the Colgate Optic White ComfortFit Teeth Whitening Kit work?

“The LED itself does not whiten your teeth," dentist David Chen, DDS, explains. "What it does is inject energy into the peroxide whitening gel, which causes [dark stains to] decompose." Now, don’t be afraid of the word “decompose"—Dr. Chen assures me my teeth aren't going to fall out of my head.

He explains that the bright light decomposes stain bonds, aka, the very-scientific, color-absorbing double bonds on your teeth that cause yellowing and discoloration. When hit with an LED light, these double bonds undergo the process of decomposition that turns them into single bonds, which reflect more light and make teeth appear whiter to the eye. “What you may find interesting is that these tooth stains don't exactly disappear... all that happened was that the double bonds became single bonds," Dr. Chen says. "Technically they are still there in your tooth but they just become invisible to your eyes since it is now reflecting light instead of absorbing."

So, unlike traditional teeth whitening strips, the LED whitening essentially camouflages stains and discoloration.

My honest review of the Colgate Optic White ComfortFit Teeth-Whitening Kit

Now that we have the "how," it’s time for the experience. According to the box, I would see increased whitening after three uses, with a dramatic difference after 10 uses.

What's included:

The ComfortFit Teeth-Whitening Kit comes with four pieces total: A whitening pen, a lightning connector for Apple devices, an LED mouthpiece, and the case for the head of the LED mouthpiece.

What puts the "comfort" in "ComfortFit" is the LED device itself, which features a soft, silicone mouthpiece that's pleasant to keep in your mouth during treatment. It's moldable, so it fits the shape of your mouth perfectly. The device connects, via a long cord, to a mobile device or power bank with its adaptable head— you choose whether you need a USB-C connection or use the lighting cable attachment.

My experience:

Ahead of even opening the box, I downloaded Colgate’s free mobile app on my phone, which allows users to create a personalized whitening schedule with daily reminders. Through the app, I also gain points that I can redeem in exchange for real products. If there’s a way that I can get my next tube of toothpaste for free, I’m gonna do it.

Once the app was on my phone, I took a picture of my teeth and opened the box. Following the instructions, I clicked the pen about 12 times to get the serum flowing (I was told it can take up to 20 clicks) and dried my teeth with a piece of paper towel before applying the serum. Unlike the whitening strips and gels I've tried in the past that hurt my whole mouth, I only felt a little tingle near the gums on one individual tooth, which was a good sign I could proceed comfortably.

Then, I waited the recommended 15 seconds before popping the LED strip in my mouth. To activate the LED strip all I had to do was plug it into my phone and click the "on" switch, which made it super convenient and hands-free to walk around with. I had just taken my evening shower and was wearing a robe with pockets, so I just tossed my phone into my pocket with the device in my mouth and let it go to work. It beeped once after five minutes (the halfway mark) then twice after 10 minutes to alert me my treatment was complete.

At the 10 minute mark, I shuffled to the bathroom to look in the mirror, brushed away the cured serum (which you can technically leave on over night, but it feels a little filmy, so I brushed mine away with warm water), and took another photo. I was pleasantly surprised that there was a difference from the first photo I took. I even noticed that my once tingly tooth felt fine.

Before I knew it, Day 3 came, and my teeth looked whiter. Not drastically whiter, but a bit sparklier. By Days 4-7, though, it felt like my results had plateaued. The photos I were taking didn't look at difference at the day before. It really wasn't until Day 10 that I realized how much progress had been made. After my final treatment, I put my pre-treatment photo side-by-side with my newest result. My jaw fell open as I realized just how far my teeth had come. Were they as white as a paper towel? No. But, they were significantly whiter than I’ve seen them in ages. Absolutely. Suffice to say, I'm glad I trusted the process.

Photo: Author

Final thoughts

While using the Colgate Optic White ComfortFit Teeth-Whitening Kit was an overall positive experience, there are a few drawbacks I noted. For one, after Day 5 I noticed a bit of a film forming between the bristles of the gel-whitening pen that made it difficult to get an even application. Fortunately, I was able to just pull them out.

The app could also use some improvement. On Day 6 I didn’t get to do my teeth-whitening treatment until 12:15 a.m., so I marked that I did it for the day. The next night, when I went to do my teeth whitening at my normal time of 10 p.m. like I had scheduled (technically on the same day), I couldn’t check it off in the app without risking not gaining points. Turns out, you cannot have completed two sessions in the same calendar day. I wish I could change that to a 12-hour limit so that if I have a late night again, I don’t lose out on points.

All in all, I think this treatment did what it said it would do and effectively whitened my coffee-stained teeth. If you want to embark on this teeth-whitening journey with the Colgate Optic White ComfortFit Teeth-Whitening Kit, make sure to heed dentist Chen’s words of wisdom: “I would complete the full whitening treatment which may be a week or two depending on your product,” he notes. If you ever want a touch-up, Chen recommends doing so every six months, but of course consult with your dentist for the best game plan for your teeth-whitening journey.