Colgate Optic White ComfortFit Teeth Whitening Kit with LED Light and Whitening Pen, LED Teeth Whitening Kit, Enamel Safe, Works with iPhone and Android

It works with no enamel errosion.
This does work and is approved to not errode enamel so is ADA approved and sold by Colgate and Crest. The only problem for me is that I’m missing some teeth so without the partial in… And u can’t use this with them in,, it’s really hard to bite down on the mouth piece where there r no teeth to grip it.. but I make it work.. privately. It will make a big lightening effect.

Good for price
I’ve been using this product for the past couple months now and I have to say it works really well. It lasts a very long time. The pen itself is really easy to use. You have to dry your teeth to put it on and then the LED light even plugged into your phone to use. It is insanely helpful and easy and automatically turn off when the timer is done. I have noticed my teeth getting whiter throughout using this.HIGHLY REMCOMMEND

VERY hard to keep in place.
The mouthpiece is VERY difficult to keep in place. The tabs provided are small – barely the with of the teeth. The plastic is smooth and there’s no groove for your teeth to grip so it easily slips out when even before it gets wet. Additionally, the curve of the mouthpiece doesn’t match the front teeth so your teeth aren’t just holding it in place like other devices. You need to continuously exert effort to keep it from straightening out, pulling away from your teeth and pulling those little tabs out from between your teeth.
I can’t say how well this device whitens teeth – my jaw was exhausted well before the first 10 minute treatment was complete and I decided to return it.

It worked for me
In the past couple of years I went to two separate dentists to professionally whiten my teeth and it didn’t work. I was told that professional whitening didn’t work for everyone and I was one of the small percentage where whitening wouldn’t work.
I used this Colgate whitener over the recommended 10 days and noticed an improvement in the color of my teeth though.
My particular situation: I have a crown in the front that was put in over 15 years ago. My teeth got stained over the 15+ years so the crown looked whiter than my other teeth. Although my teeth didn’t whiten to match the crown there was a noticeable improvement and the crown didn’t stand out as much as it did before. I plan to buy additional pens and continue to use this whitener in the future.

If you use it for 10 days as instructed, you will see a difference, but the pen doesn’t work well or last long. There’s no good way to clean the pen without it ending up a mess.