Teeth whitening (bleaching) is a process which can make teeth up to seven or eight shades whiter.
Whitening is a chemical oxidation reaction of the external tooth surface using hydrogen and carbamide peroxide based chemicals. There are two ways of teeth whitening: surgical and night-time whitening. With surgical whitening the results are faster, but the chemicals that are used are very concentrated. The night-time whitening is done by the patient, using with transparent foils which are put over the teeth and which contain low concentrations of chemicals. The results are slower, but this is less aggressive for the tooth surface.