told me in an email that hydrogen peroxide or carbamide peroxide are “most effective in a gel form that is held against your teeth (think whitening strips, gel in trays, etc.).” Each method ...
If you want whiter teeth, you don't need to shell out huge ... usually using hydrogen peroxide or carbamide peroxide. If that doesn't sound like something you're interested in, there are also ...
A mould of the teeth is taken and a mouth guard made to exact specifications. The patient wears the mouthguard filled with a whitening gel made from carbamide peroxide or hydrogen peroxide.