The Crest 3D White Radiant Express Strips work really, really well. My teeth look whiter just after using it a few times and Im excited to see the results after the full 14 day treatment course. The strips are very easy to apply, they peel off easily and adhere to teeth without slipping. I didnt have any problem keeping them on my teeth for 1 hour, while I worked around the house. After I used them a couple days in a row, I did notice mild tooth sensitivity but it resolved as the day went on. I did take a break for a day from using the strips and it didnt happen since. I would recommend using these strips every other day or every few days if you have sensitive teeth to avoid sensitivity.