Over the years, teeth become stained and worn from food, drinks, medication and personal habits such as smoking. Whitening coats the teeth and this procedure can be done in the dental office or at home. Tooth whitening is a process by which the teeth are made whiter using peroxide-based bleaching gels of varying concentrations (from about 8% to over 30%, depending on how it is applied).
The process has become popular in recent years as our image-conscious society strives to maintain a more youthful appearance. Bleaching solutions generally contain carbamide peroxide and hydrogen peroxide as the active bleaching ingredients.Carbamide peroxide breaks down into hydrogen peroxide and urea upon exposure to water (including saliva). Other ingredients include stabilizers (which help prevent decomposition of the bleaching ingredients), preservatives (to prolong the shelf life/effectiveness of the product), and pH (acid) balancers.
Bleaching teeth works because tooth enamel is somewhat porous allowing the bleach solution to penetrate its surface and neutralize pigmented molecules from coffee, cigarettes, colored beverages, and other external sources.