How does whitening gel work?

There is an active agent in every whitening gel which gets inside the discoloured segment and dislodge the dark particles.
The common theory is that free radicals from the active agent (hydrogen peroxide, carbamide peroxide) attack organic matrix inside the tooth. That new formed matrix reflects less light, so tooth appears brighter and lighter in shade. The active agent removes the discolorations as well as alters and brightens the inherent colour of dentin.
At Tauranga Crossing Dental we use an advanced tooth whitening system making the whole experience easy, painless and highly effective.