Review on 🦷 AZ Smile Teeth Whitening Pen (3 Pens): 30+ Treatments, No Sensitivity Gel, Travel-Friendly Whitener, Removes Stains from Drinks, Smoking, Coffee, Wine by Matt Duffy

I love these bleaching gels because they can get into the darkest corners. They have a good viscosity so they don't drip everywhere. What I like most is the precise brush tip and the ratcheting syringe to avoid waste and overflow. This is the best applicator I have ever used. Super easy to use. There are clear instructions on the packaging and insert (refrigeration recommended), but no mention of ingredients or strength. While the gel blisters like other peroxide bleaches I've used before, it doesn't feel as strong as the gel I usually use which is 35% peroxide (just based on mouthfeel and tooth sensitivity). Difficult to pinpoint the level of whitening, but it seems to work. I'm guessing somewhere on the order of half a shade every three or four treatments. Weak sensitivity seems to go away after a few days. No noticeable gum irritation. Good price $18. In general I am very satisfied, but I would like the concentration of peroxide to be indicated. 4/5 stars.