First, you apply a bleaching gel to your teeth for a certain amount of time each day. Most kits come with a set of trays (which look like mouth guards) that fit your teeth and hold the gel in place.
The bleach seeps through your tooth enamel to whiten the dentin layer below. Dentin is naturally a darker yellow color, which is why our teeth aren’t perfectly white in the first place.
Teeth whitening pens
Whitening pens are more like brushes; they consist of a small tube of gel that is applied directly to teeth via a built-in brush.
Pens usually contain hydrogen peroxide or carbamide peroxide, although some peroxide-free brands are available. Users like them because they’re so convenient; you can carry them anywhere and use them whenever you have time.
Treatment takes 1-2 weeks, with about two applications per day lasting between 5 and 30 minutes, depending on the manufacturer.
There are numerous brands and types of strip solutions, but they all share some characteristics in common. White strips, in general, are thin, flexible, transparent, or translucent strips that are coated on one side with a tooth whitening gel.